It's Raining! (Now What?)

A reprise of a post from a few years ago seems appropriate given today's welcome visitor… I originally wrote this on January 18, 2010; and while some names and statistics may have changed since then, the core message remains the same.—JB

It's been hard to miss the message over the past year that we're in a drought. And Californians have responded remarkably well: residential water use was reduced by 9.4% in Santa Clara County, 12% in Los Angeles County, and up to 25% in San Diego County from previous periods. I still see far too many gratuitous lawns, thirsty "exotic" plants and wasteful irrigation systems. But on the whole, we're at least trying to handle our water.

So the next place to look is, naturally, increasing our supply. And on the cusp of a major El Niño week like the one currently forecast for the Bay Area, the opportunities seem abundant. So why isn't everyone harvesting rainwater? To understand why it's not quite that simple, let's do a little math:

First, let's assume we're in for nine inches of rain — that's 3/4 foot — over the next week or so.

Second, let's assume we can harvest that rain from the roof of our detached 2-car garage, which has a roof area (equals footprint) of about 20 feet by 20 feet.

So if we catch every drop that falls on our roof, we would harvest 20' * 20' * 3/4' = 300 cubic feet.

Using a handy-dandy volume converter, we find that 300 cubic feet equals 2,244.156 gallons.

Holy crap! Seriously?! More than two thousand gallons? That can't be right.

Well, actually, it isn't right. Because we won't catch every drop. Some will splash away, some will get trapped in the gutters, some will leak out. So a capture rate of 60% is usually considered reasonable, and our potential volume actually is 2,244.156 * 60% = 1,346.494 gallons.

Holy crap! Seriously?! More than thirteen hundred gallons?

Yep. And unfortunately, that huge number is less than 5% of the annual water needs of a 1,000 square foot lawn. Never mind that if you're serious about water conservation, you don't have a 1,000 square foot lawn; are you getting a sense of the quantity of water we're talking about? Say you did have a 20'x50' patch of grass: 1,346 gallons of rainwater would irrigate it for all of about two weeks. For the year you'd need twenty times that, or around 27,000 gallons.

Which raises another issue, specific to Mediterranean climates like ours where most of the rain comes in one season, as opposed to throughout the year: storage.

We get most of our rain during the winter, when plants are dormant and evapotranspiration rates are low. We don't need the captured rainwater now. We need it six to nine months from now, when skies are sunny and the ground is parched. Even if you have no lawn and your xeric garden only needs 1,300 gallons, where do you store what you've saved?

There are in-ground cisterns, which may be large enough but are pricey and complicated to install. There are classic, above-ground rain barrels, which are bulky and difficult to link together for additional capacity. There are interesting systems like the Rainwater Pillow which can efficiently store 1,000 gallons or more, but may not be ideal for exposed outdoor locations. And there are modern above-ground tanks such as the Rain Box and Rainwater Hog, which link together with slim rectilinear profiles that use space efficiently but can become pricey.

How pricey? The Rainwater Hog sells in the neighborhood of $500 per 50-gallon tank. To catch 1,346 gallons requires 27 tanks, or $13,500. The Rain Box is more economical, at about $250 per 75-gallon box. But that's still 18 boxes, or $4,500.

Even if cost isn't a consideration, space may be. The Rainwater Hog has such a slim profile — just 20" wide by 10" deep — that it can be mounted not only vertically against walls, but also horizontally, e.g. beneath a deck. But no matter how you set them up, 27 tanks would take a lot of room: far more than the 20' wide wall of our two-car garage. The Rain Box is bigger, about 24" wide by 20" deep, and not designed to mount horizontally; so 18 boxes would need at least 36', or almost two full walls of the garage.

I don't mean to discourage anyone from catching and reusing every drop possible. Even if your "rain barrel" is a garbage can, that's 20 or 30 gallons you don't need to draw from a reservoir. But it won't be your only solution, and in fact might raise more questions, e.g. what do you do with the overflow? We all can install green roofs, detention basins and porous paving, which will help the rain get into the groundwater where it actually can do some good. But these solutions aren't the same as storage; and they're not cheap, either.

I guess my point is that it ain't easy to save the world. It's probably not economical, and you probably won't get your money back. Serious rainwater harvesting requires some serious commitment, and we're not all there just yet. But even if you're not ready to shell out thousands of dollars to store thousands of gallons, you have plenty of other options. Maybe you can swap out your lawn for a delightful garden of unthirsty plants. Maybe you can mulch those plants with 3" of compost instead of leaving the soil bare. Maybe you can redo your driveway with pervious pavers instead of asphalt. Maybe you can take shorter showers or make other changes that reduce your water footprint.

Maybe you can't do much; but you can do something. And what better time to start than now — while there's a break in the weather?

Do-It-Yourself Landscaping

Occasionally I use this space to answer private questions in public. And occasionally I run out of new material. So today I'm addressing the second with a redux of the first, originally asked a couple of years ago but even more relevant in This Economy. Got a landscape design question of your own? Ask away!

Does-It-Himself Greg in San Carlos took a break from remodeling his home to write:

"Here's the problem: I'm a cheap bastard. More specifically, I like a nice yard with blooming vines, healthy hydrangeas and lush, jungle-green ferns. And if there's any way I can plant them and care for them myself, I will. "After our remodel we're going to need to do some substantial landscaping to the front and back. Me being me, I'm thinking I can do it myself. With that in mind, I have dug up and saved hydrangeas and ferns and roses that had been in the line of fire, and I even had the crew dig up and replant a very mature camilia (so far, so good). The crew also cleared out a rotting hot tub and old deck so that we will have much more room in the backyard, where I'd like to put in a small lawn and use plants that thrive under two large Monterey pines. "So my question is, what the hell do I do now? Am I in way over my head? Which aspects of he project should I pay the pros to do, and which could I realistically do myself?"

Greg, your, um, frugality means you need to work extra hard to define two things: (1) your budget, and (2) your priorities. On the first count, you've got to do your homework and figure out exactly how cheap you really are. How much can you spend without losing sleep over it? Remember that remodels have a funny way of costing a bit more than expected; do you want to sock any money away in a special "landscaping" bank account before it's all spent? Don't worry right now how the money will be used—just be honest, pick a finite number, and make it inviolable. (Hint: involve your wife in this exercise.)

On the second count, take stock of what will really bring joy to you and your family. How much lawn will you and your kids really use? Will you need a spot to grill steaks? A shady place to sit and relax while the kids romp? I'm guessing you're the gardener—how much time will you really have each week to keep the yard looking its best? What yard chores will you enjoy, or dread? Is it important to you that your yard look "mature" soon, or can you wait a few years for things to fill in? Make a list of every quality you'll want. Dream out loud. (Hint: involve your wife in this exercise.) Then rank them from highest priority ("absolutely must have") to lowest ("icing on the cake"). This will tell you where your finite number, see above, should be spent.

But let's back up a step or two, Greg. I get that you're, um, economical. My dad was, um, thrifty too: he'd drive across town to fill up at the gas station that was 2 cents cheaper than the others. But what did he actually save? Nothing. Worst of all, he didn't take any real joy in the process or pride in the outcome. So back to you: what's your aversion to hiring a pro to come up with something that's beautiful, within your budget, and facilitates the life you want to live?

Of course you could do it yourself. You could glean tips from garden design books and blogs, copy planting plans from magazines, learn how to design and install irrigation and lighting systems, rent a pickup and a Ditch Witch and a Rototiller, lay your own sod and install your own shrubs. It's not quite rocket science, even the irrigation part, and if you're really a cheapskate, you can do all of this. You'll save a bunch of money. But you'll also be out a bunch of time — time with your wife who adores you, your sons who revere you, your friends who enjoy you, your avocations which enrich you, and probably even your work — which presumably affords you the possibility of not having to spend all your free time on this.

So that's where I would draw the line: What aspects of the project would you truly enjoy? If you aspire to design green spaces, if you love learning about plants and experimenting with what you've learned, then take that on. If you love getting your hands dirty and putting small parts together to create complex yet rational systems, then take on the irrigation/lighting installation. If you love getting your hands really dirty while getting a fair amount of exercise, then take on the soil work and planting. Take on what you'll love… and hire a pro for the rest of it. The money you spend will come back to you in well-designed spaces that enhance your precious time with your family; in well-selected and well-installed plants that thrive under those pines; and in well-designed systems that perform efficiently every day.

I feel like we're just getting started, so tell you what: in a couple of posts, I'll write about how you can keep your costs down when you do choose to hire a pro. Just remember: my advice is worth exactly what you pay for it.

I Hate Being Right About This

Rain or no rain, it's officially a drought emergency. I hate being right about things like this.

So: are you ready to cut your water consumption by 20%? Even before you kill your lawn, schedule a house call: water agencies in San Francisco, the East Bay, Redwood City, and most* of Santa Clara County offer free basic inspections that calculate water usage and point out opportunities for conservation both indoors and out. Santa Clara Valley Water District also is hosting a "Water Efficient Landscaping Workshop Series" including one of my favorite local designers, Alrie Middlebrook.

*California Water Service doesn't offer house calls, but does offer free fixtures and other resources for their customers in Los Altos, Los Altos HIlls, Menlo Park, Cupertino, Sunnyvale, San Carlos, San Mateo and South San Francisco.

And if you want to get an in-depth analysis of your landscape water use, contact a certified irrigation contractor, who will put your system through its paces and really optimize it according to detailed, standardized guidelines.

The prospect of reducing our water use by 1/5 is about as cheering as the stock market these days. But if you've been considering changing up your landscape, this is an opportunity to do it right — and perhaps even get paid for it! With a little professional advice, you can wind up with a yard that is easy on the eyes, easy on the wallet, and easy on the earth as well.

More Rain, Please

“unless the next six weeks deliver rains of biblical proportions, Californians will face major shortages this summer”

So writes Kelly Zito in today's Chronicle. When I wrote about the drought a couple of weeks ago, Lake Shasta was at 31% of capacity. After two weeks more or less full of rain...

Lake Shasta is at 32% of capacity.

For us down here at ground level, it seems like things have really turned around. Our lawns are squishy again; trees are budding out; the rain breaks just often enough for the ground to soak it up, then starts up again. The problem — actually, the two problems — are that (a) squishy lawn at sea level doesn't translate to snow up in the Sierra, where our water comes from by the time August and September roll around; and (b) this is the third consecutive year we've had low rainfall, so the ground is simply parched — as evidenced by how fast my rain garden drains out.

So I repeat my warning about getting water-wise: the drought is coming. Water, especially to irrigate landscapes, will be in short supply, expensive, or both. Gardeners, landscapers and homeowners will have to change the way we think. That will require no small effort, so lazy me hopes I'm wrong. But I drought doubt it.

Not Quite The Apocalypse… Yet

Since I wrote last summer about the threat of drought, things have gotten worse — much worse. The Sonoma County Water Agency has announced mandatory usage cutbacks of at least 30%. In the East Bay, EBMUD has called for 19% reductions, and implemented rate increases for all usage. Bolinas has already emptied one of its two emergency reservoirs, and is limiting household usage to 150 gallons per day (repeat offenders will have their water supply cut off). The Sierra Nevada snowpack is at 61% of normal, and the state's largest reservoir, Lake Shasta, is at 31% of capacity.

So what's a gardener to do?

For starters, kill your lawn. Turf is by far the thirstiest aspect of your landscape, and even if the water is available it's going to cost you an arm and a leg to keep it green.

Next, audit your landscape water usage. Hire a certified irrigation contractor or irrigation auditor to ascertain whether your system is using more water than necessary. Are there leaks in your pipes? Could your run times be shortened? Could those spray heads be converted to drip? The investment will pay for itself.

While you're optimizing your irrigation, optimize your plantings as well. Make sure your plants are grouped together by water need — ferns with dogwoods, sages with grasses, Carex well away from Ceanothus. While you're at it, take another look at some of your thirstier specimens: do you really need those hydrangeas and roses?

Finally, when every drop counts, it makes sense to save every drop you can, and a rain-catchment system is one of the best ways. We've seen the traditional rain barrel any number of different ways, but there are a few other options available now, such as the Rainwater Hog which can mount either vertically against a wall, or horizontally beneath a deck.

Don't forget, Santa Clara County is offering rebates for water-thrifty planting and irrigation updates. But whether you take advantage of the rebates or not, the time to make your garden water-wise is now.

Water in the Landscape

California is officially in a drought (although personally I suspect this is our normal climate and those other years were just extra wet). Some water districts have implemented mandatory rationing, while others are still able to request voluntary cutbacks… for now. But it behooves all of us to be conscious of our water use, and water-wise landscaping is an easy first step.

The Santa Clara Valley Water District has created a very nice booklet on landscape planning, from layout to planting and of course irrigation practices. Their site also offers a list of water-wise plants, not exhaustive but certainly robust enough for most of us. And, if you needed any more incentive, the district is offering a landscaping rebate of up to $1,000 to replace your thirsty turf lawn with more efficient plantings, or an irrigation rebate of up to $1,000 to install drip systems, rain sensors and other "smart" irrigation products.

The Association of Professional Landscape Designers also has issued guidelines to keep its members cognizant of practices that not only reduce irrigation needs, but also respect natural cycles by encouraging stormwater detention and holistic ecological planning. The American Society of Landscape Architects has also issued some pointers on conserving water as well as greening your home overall. And the California Landscape Contractors Association offers not only tips on how to "reduce your use," but also resources for finding certified water managers to install or optimize your low-water landscape.

The threat of a serious and prolonged drought is an abrupt wake-up call for all of us, and the options for adapting to it can be overwhelming. Start by speaking with your landscape professional — designer, architect, or contractor — and you'll get both reassurance and real solutions to save water and save money.

Where All the Gardens are Above Average

Lately I've been playing the Gas Mileage Game: with my car's feature that tells me my current average MPG, I see how much I can goose my fuel efficiency by, say, accelerating on downhill grades and coasting as far as I can on the uphills. It's a great trick to play on yourself to begin the game just before hopping onto the freeway, where even an SUV like mine can exceed 25 or even 28 miles per gallon. But after just one day driving around San Francisco, my average plummeted to 16; and even a week of highway driving couldn't lift my average MPG back up above 17.

It occurs to me that landscaping is subject to the same law of averages, in terms of both functionality and aesthetics. If you have, as I do, a very water thrifty yard but even a small patch of lawn, the lawn is an insurmountable drag on your irrigation efficiency. Likewise, if 90% of your yard is gorgeous, breathtaking even, but 10% looks — well, less than breathtaking — perhaps due to outdated materials or past-their-prime plants you couldn't bring yourself to remove — that minority will bring down the appeal and allure of your entire landscape.

A few of my first-time clients have been shocked when I recommend removing an established tree or shrub that, while not particularly right for their landscape, is a fixture in the yard nonetheless. But the more "average" yards I see, the less sentimental I've become: now I'll counsel that the sooner you remove an ill-fitting or underperforming plant, the sooner you can begin establishing the right plant in the right place.

Similarly, I've met with home owners who have actually told me, "well, we want to upgrade the yard, but we don't want to make it too nice or anything." Which is a little shocking for me: I mean, why wouldn't you want the best space you can afford? A space designed precisely for your tastes and lifestyle, that you love coming home to or spending time in?

A professionally designed garden, well maintained and thoughtfully updated over time, is what will lift the landscaping above average — and keep it there.

Water the Plants, Feed the Soil

My youngest assistant, seen here, hasn't quite got the concept down, but you can: the most efficient way to irrigate (especially in these hot dusty times) is to put just as much water as needed as close to the plant's root zone as possible. This is the principle behind drip irrigation, and it can work equally well with attentive hand watering (for which 4-year-olds are not known).

The other half of the equation is the nutrition your plants are getting. It's tempting to toss a handful of Osmocote or Miracle-Gro (did you know they're both made by the same company?) at the bases of your plants. But this only supports root development at the base, where the roots already are; it does nothing to encourage them to spread out into new ground, which in turn increases the plant's ability to take up water (especially in these hot dusty times).

A great way to enrich the soil on a broad scale is with consistent and generous applications of compost mulch; aim for 2-3" every 6 months. Added bonus: a healthy layer of mulch also helps prevent your precious water from evaporating, which keeps your efficient irrigation practices efficient.

(By the way, you'll notice the mulch is conspicuously lacking in my photo. Just do as I say, not as I do.)

Geez, It's Hot.

Geez, it's hot. It's been hot all week, even in San Francisco, even with overcast skies and a westerly breeze that normally chills things to a level that Kenmore should aspire to. Nope, it's been hot, 80 degrees at 5pm in The City, the same at 10pm down on the peninsula.

There's a sort of ritual among old-timers here: when it gets hot like this, open the doors and windows all night to flood the house with cool air, then shut 'em up tight and draw the blinds all day to keep the heat out. It's a pretty good system, and we used it quite effectively in the 1936 bungalow we lived in until recently. The attic trapped and isolated the hottest air, and the crawl space was a permanent reservoir of coolness. The system takes a bit of getting used to, but it works.

Then a couple of years ago we moved into a brand-new house, built to the latest standards and undoubtedly more energy efficient than last century's technology.

Except it's not.

This house is terribly inefficient. Instead of a full attic, the bedrooms have high peaked ceilings that conduct heat in from the roof and hold it in the room all night (compounded by the fact that the bedrooms are upstairs to begin with). Big skylights provide tons of light... and also transmit tons of heat, without opening to vent any of it out. The crawl space is minimal, so even the ground floor heats up relatively quickly and cools down slowly.

Why would someone build a house this way? Because they also plumbed it for air conditioning. I suppose the thinking was, "as long as we've offered a solution, there's not a problem." Heaven forbid they should have spent more time or money building a smarter house; just throw natural resources at it instead.

Unfortunately, I see this kind of short-term thinking all the time in garden-making as well. Gratuitous lawns are the classic case — fast, cheap, attractive, so what if it takes 100 gallons of water a day? Same with trees that have no business growing >100 yards from a river, yet get plunked down in the middle of town: don't change your planting scheme to include water-wise plants — just increase the irrigation! Then there's hardscaping: impermeable asphalt driveways are replaced with impermeable concrete driveways. Existing concrete paths and pads are broken up and carted off, with new concrete masonry units carted in to make new patios and retaining walls. Dining patios get sited in full sun, demanding that a shade pergola be built, rather than in the shade of existing trees.

A few decades ago pioneering landscape architect Ian McHarg wrote his seminal work "Design With Nature". He challenged land planners to analyze, understand, and work with natural systems rather than bulldozing through them. His advice still holds today — no matter what the scale of the project.

What are you doing to design with nature, or to overcome the problems created by those who didn't?

Baby, It's Hot Outside

Even as East Bay MUD proposes its first water-rationing measure in two decades, this week temperatures are expected to soar toward the century mark.

For your garden, this means get a head start (i.e., now) on keeping your plants hydrated. If you're irrigating with a spray system, see whether your controller can be programmed to repeat cycles — so that rather than watering once for ten minutes, which may deliver more water than the soil can absorb at once — your system waters each zone once for five minutes, then repeats the cycle for another five — so Zone A is absorbing while Zone B is receiving. If you're not sure how much water your plants should be getting, get to know your local Master Gardener; you can also extrapolate some good information from publications developed for commercial growers.

If you're irrigating with a low-flow (drip) system, you will want to increase the length of each cycle and/or add a "syringe" cycle in the middle of the day, effectively giving the plants a drink when their transpiration rates are highest.

You'll also want to make sure all that precious water stays in the soil, where the plants can actually get it, rather than evaporating into thin air. The most effective way to do this is with a generous layer of mulch. Most often we think of mulch as fir bark, which is ground to various consistencies (or shredded into "gorilla hair").

However, there's more than one way to mulch: compost is wonderful, adding nutrients to the soil even as it holds water in; and even pea gravel is effective (although pricey and doesn't decompose like organic matter). Some municipalities even give away free compost to residents. The key with mulch is to apply it generously (I prefer a depth of least 3 inches) and regularly. Remember, organic matter like bark and compost break down over time; so plan to reapply an inch or so at least a couple of times a year.

There are plenty of other considerations in creating "water-wise" gardens. The California Water Service has some good resources, including a list of drought-resistant plants; if you've got good tips for getting your garden through the heat, please let me know!

(Happy) Earth Day

Hooray. It's "Earth Day." One day, 24 hours, for us to be more aware and appreciative of the Earth's environment.

Woo hoo.

Never mind that the other 364 days of the year we're driving our SUV around town, alone and comfy in our captain's chair.

Or that we still leave the water running while we wash our hands with antibacterial soap.

Or that our salmon are now in as much trouble as our tuna.

I put honey in my tea today and was confronted by two unwelcome thoughts:

If this isn't "organic" honey, what crap pesticide residue am I drinking now?

When the bees go extinct, how will I put honey in my tea?

Across the street, the neighbor's sprinklers spray well beyond the curbside planting strip, flooding the gutter and soaking the cars parked there. Then the gardener fires up his gas-powered leaf blower, creating great clouds of dust and grass clippings and pollen that immediately adhere to the wet cars. I am not making this up.

It seems to me that we, as a society, have gone mad. We are pathological, behaving in ways that clearly harm others, if not directly ourselves. We are compulsive, unable or unwilling to modify our behaviors even when it's made clear that they are destructive. And we are delusional, somehow believing — despite overwhelming evidence to the contrary — that our actions either don't have consequences or will be mitigated by someone else.

It's been about two years since Al Gore's An Inconvenient Truth made us all wince just a little bit. And yet the troubles have been on people's lips for more than 15 years — I caught Batman Returns on TV over the weekend, and even in 1992 the Penguin referenced "global warming." I understand that sometimes Hollywood can seem out of touch, but major studio releases don't make their money referencing arcane phenomena advanced only by the intelligentsia.

I was going to write today about a few things we all can do to help our planet, our neighbors, our children. Little things, things you might actually do, like converting your lawn to low-water plantings, not like converting your SUV to biodiesel. But honestly, we've known we're in trouble for, let's conservatively say, a decade. What have you changed in that time? Have you converted your lawn to low-water plantings? Have you stopped buying products whose manufacture kills the environment? Do you recycle and/or compost most, if not all, of your waste?

If you have, great. I applaud you. Tell us all about it, if for no other reason than to help us sustain our delusion that someone somewhere is fixing the problem we're creating. But when my clients still demand lawns that no child will ever play on… when "my" contractors still install spray irrigation because drip is too difficult… when I myself still drive my SUV around town, solo… I think perhaps the problem is outpacing the fix.

So, seriously: what are we going to do about it?

A Little Cold For April

If you're thinking the last few days have been a little cold for April, you're right. In fact, yesterday San Francisco tied its record low for the date and Oakland set a new record, according to NBC11.

By itself the cold snap wouldn't be a problem; but with the weather so deliciously warm for the past few weeks, just about every last plant that had been holding on to dormancy has decided it's finally time to bust out the buds... which leaves them vulnerable to these frosty conditions.

Making the problem worse is the wind, which can chill us down another 10 degrees or more and, even worse, increases the rate at which plants transpire (i.e. lose) water. So the biggest danger isn't actually freezing: it's dehydration.

Ironically, the best defense is the same practice you would use on the hottest days of summer: water your plants, slow and steady, at least once if not twice a day. Make sure the irrigation arrives right onto the soil around the plant's dripline — ideally you have a low-flow system so there's little or no loss, but if you do have spray heads make sure they're not wasting water up into the air. The breeze is often calmest in the pre-dawn hours, so that's a good time to irrigate with little fear of the wind carrying the water away.

(On a side note, if your system is "misting" clouds of water up into the air, your system may be operating with too much water pressure — usually a result of improperly sized pipes. If you can, choke down or manually reduce the flow to your irrigation mainline to see if the misting stops.)

Also, make sure your mulch is adequate: I like to recommend a 2- to 3-inch deep layer of redwood bark or coco hulls, but I've also taken to using the coffee grounds my local java joint bundles up and sets aside. (By the way, they smell awesome for a day, then they just smell like stale Folger's.) Mulch helps the soil retain water, and it also creates the cool, aerated conditions that beneficial mycorrhizae love. No doubt the weather will warm up again soon, and your plants and soil will be prepared for their next challenge: our Mediterranean summer.

Next Stop, Spring

Winter reveals the garden's bones.With only a forecast of showers next weekend standing between us and Spring, now's your last best chance to take care of those winter to-do items and get your garden ready for peak season.

First, cut back grasses to about 6" above ground level, to make room for the coming flush of growth. If perennials such Mexican sage are beginning to regrow from their base, cut those back as well. Woody shrubs such as Salvia greggii, hydrangeas, viburnums and dogwoods may also be showing new growth along their old branches; I trim these back to just above a new growth node about 1/2 or even 2/3 back from the ends.

Second, clear out anything that's obviously dead. Give serious thought to also removing any specimens that struggled last year: it wasn't a particularly brutal year, so anything that didn't thrive probably is in the wrong location (or receiving the wrong care) and won't do much better this year. With this riffraff gone, step back and evaluate the "bones," or basic structure, of your garden. Are there gaping holes? Overly (or underly) vigorous specimens? Poorly shaped trees or large shrubs that are blocking light, views or paths? "Dead end" views with no payoff? Make a list; I use a map of the garden with numbered items in place.

Third, revisit your garden wish list. Is there anything you wish for more of: color, fragrance, movement, wildlife? Anything you've seen in your travels -- whether plants or pots, furniture, lighting, or other ornaments -- that you'd like to try replicating at home? Again, make a list, collect pictures, and start (or update) an idea file. If possible, also identify a budget and prioritize your list into "must have," "nice to have," and "if I win the lottery" levels of importance.

Fourth, give your "tools of the trade" a checkup. Run your irrigation systems and check coverage and pressure; test hoses for leaks; check lighting systems for burned out bulbs or broken fixtures; and sharpen your shovel, spade, hoe, pruning shears, loppers, and lawnmower blades (many local hardware stores offer sharpening services). Also make sure your gloves, knee pads, hat and other gear are in good shape.

Finally, make sure your team of garden experts is at the ready. This might include a landscape designer, landscape contractor, fine gardener, arborist, irrigation specialist, and/or nursery. And if you'll be doing the work yourself, schedule a massage (or chiropractor visit) for the next day. After all, there's no reason all this work can't have its rewards.

Red Ink, Green Joy

Lunaria annua (Money Plant),
by Christian Fischer

On my soggy drive home today, talk radio was filled with opinions about the pending "economic stimulus package" and the looming recession driving it. Lots of doom and gloom, both here and abroad. And it got me thinking (as most things do) about gardens and the people who live with them.

On the one hand, a well-designed garden is a true luxury: it doesn't shelter us from these incessant rains, it doesn't furnish us with cotton or wool to spin into garments. It costs money to design, money to install, and money to maintain. The average bribe rebate from our government will be something like $1600, which will hardly buy you a yard full of gorgeous plants, much less my design fees to wrap them up into a dramatic and fabulous package. Let's face it, you need a custom garden about as much as you need quilted teddy bears on your bath tissue.

On the otherhand, a well-designed garden may be an absolute necessity, especially in darker times. It can save you money on energy and water through intelligent planting design and efficient irrigation and lighting. It can lower your grocery bill by providing physical sustenance, i.e. delicious fruits and vegetables, every month of the year. But most importantly, it can bring you joy every day by creating an environment filled with vibrant colors, intoxicating scents, soothing sounds, bejeweled birds and butterflies, or those priceless spaces where your children can play or you can relax.

So what would I advise to someone who wants to upgrade their landscaping, but isn't sure now whether that's such a good idea? Obviously, I can't tell anyone how to prioritize their budget, and I certainly don't advocate going deep into debt with a landscaping project. But given that it is a short-term investment in your spirit as well as a long-term investment in your most significant asset, maybe — just maybe — a well-designed garden is a luxury you can't live without.

Rainy Day Math Fun

Well, wasn't that refreshing?! Nothing like two inches of solid rain to wake up the winter, and more is coming down today. It's the perfect test of my vernal pool, which began filling around 8 a.m. yesterday and ultimately filled to about 6" below capacity within 12 hours. The water comes primarily from our roof, with about 2/3 of its downspouts tied into a central outlet at the mouth of the pool. (The other downspouts let out onto the permeable driveway, so there's some percolation, although I intend to tie those into the pool as well.) There also was some water siphoned in from drainage problem areas in the back yard, but probably less than 20 gallons.

A couple of things were really amazing to me. The first is that my math was more or less right! Assuming a maximum daily rainfall of about 1 inch (not quite the record, but also above the norm), I wanted the pool to hold all the runoff from my 1200 square foot roof. Ready for some algebra? Follow along:

1200 square feet
* (1 inch of runoff ÷ (12 inches/foot))
___________
100 cubic feet of runoff capacity needed

So I built the pool's surface area to about 110 square feet, at an average depth of about 12":

110 square feet
* (12 inches ÷ (12 inches/foot))
___________
110 cubic feet capacity

Sure enough, this storm dumped 2 inches of rain; and again, the pool collects about 66% of the roof area:

(1200 sq. ft. * 66%) = 800 sq. ft.
* (2 inches ÷ (12 in./ft.))
___________
133 cubic feet of runoff

But wait! Why didn't the pool overflow? Ah, let's not forget about the soil's absorption capacity. My soil isn't completely compacted, so it should still percolate at a rate of at least .75 inch per hour (not that I've actually tested it yet). We don't know the rainfall rates per hour; we do know the day's average was 2" over 24 hours, so let's assume it fluctuated between 1/16" and 1/2" per hour. The pool was receiving those rates (depths) of rain across its 110 sq. ft. area, as well as the 800 sq. ft. of roof.

800
+110
___________
910 sq. ft. total surface area

To determine what percentage of "its own" area the pool was receiving:

910 sq. ft. total area
÷ 110 sq. ft. pool area
___________
8.27

The pool was receiving 8.27 times, or 827%, of its own area. Multiply that by the rate (depth) of rain to find out what volume it was taking on:

8.27 * 1/16" per hour = .52" per hour (assumed minimum flow into pool)
8.27 * 1/2" per hour = 4.14" per hour (assumed maximum flow into pool)

This means at the peak periods, precipitation was outpacing percolation by about 4 inches per hour. That's why the pool filled as much as it did. But that was a small minority of the time: more often, percolation outpaced precipitation by .25 per hour... and that's why the pool never overflowed.

(Knowing that the pool takes on 8.27x its area, we can also determine the "equilibrium" rainfall rate:

.75"/hour pool percolation rate
÷ 8.27
___________
0.91"/hour precipitation rate)

(By the way, the second amazing thing to me was that, after about 12 hours of no rain, the pool had no water this morning. Let's see what the fill/percolation rates are today, now that the soil is saturated.)

This kind of math is what landscape designers and architects have to do all the time in designing drainage systems, water retention basins (like vernal pools), even landscape irrigation systems. It's a lot more complex than just this algebra, but I hope it shows a little bit of the "behind the scenes" work we do — it's not all just pretty pictures.

If you've hung on this long, you're probably doing the math yourself. Please correct me if I've missed something, or feel free to ask questions. It's been a fun rainy-day diversion.

PS: This whole episode has alerted me that I might consider renaming my little water feature. Technically, a vernal pool has the geographic feature of a semi-imperpeable "pan" beneath the grade which slows drainage throughout the winter and spring. Mine, obviously, drains fairly readily; so I suspect rain garden — although becoming nauseatingly trite — may be a better description. Stay tuned.

Have You Seen This Lawn?

Our good buddies at NASA have put out this image showing how much of the U.S. is devoted to turf lawns. Says NASA's Earth Observatory:

The map shows how common lawns are across the country, despite a wide variability of climate and soils. Indeed, the scientists who produced the map estimate that more surface area is devoted to lawns than to any other single irrigated crop in the country. For example, lawns appear to cover more than three times the number of acres that irrigated corn covers.

Just take a look at, Phoenix, Las Vegas, Los Angeles, or any other "desert" town to get a sense of just how important we perceive lawn to be to our way of life. Books such as American Green explore our obsession (albeit a bit pithily, says the New York Times), and magazines such as Forbes estimate that we "Americans spent $25.9 billion on lawn-care and landscape maintenance in 2006, a figure which includes, among other things, professional services and water bills."

That article goes on to mention xeriscaping -- technically, landscaping with plants that can withstand bone-dry conditions, such as the lovely specimens offered by High Country Gardens -- but also notes that local ordinances may actually override common sense, dictating plants of a certain type or lawns of a certain size.

My clients know I believe lawn is good for children and dogs, and not much else. My neighbors despise me because I've let the gratuitous patches of lawn in our front yard die ("it's not brown, it's golden," I remind them) as I await the fall planting season. My readers know I've wrestled with the dilemma of natural vs. artificial turf for my back yard (natural won, in a split and ambiguously ethical decision involving invertebrates). But I still find that most people I talk to for the first time can't let go of their vision of a lush, green lawn. Never mind that we Americans use as much as 19 trillion gallons of water and 2.4 million metric tons of nitrogen-based fertilizer annually to care for our lawns... you've got yours, and I want mine.

The drought is coming! The drought is coming!

Given that San Francisco's rainfall during the 2005-2006 season was about 157% of normal, it's a little weird to me that after one dry winter the PUC is raising the specter of voluntary or even mandatory water restrictions. Nevertheless, numbers don't lie (or do they?), so we better get thinking about how to reduce our water usage.

Which brings me back to the ultimate water hog, lawn. Brian of Mauby All Natural was kind enough to suggest he could "improve soil condition to a point where water use can drop by 75%." Brian's primary product seems to be compost tea, which is an excellent amendment and one whose regular use I regularly recommend for my clientele who are serious about improving the overall health of their soil. But turfgrass being turfgrass, I'm hard pressed to understand how it could thrive on 5,000 gallons of water a year instead of 20,000.

So what's better: spending 12,000 gallons (I'll give Brian partial credit) of our precious Sierra snowpack on irrigation each year, or tossing 750 square feet of plastic into the landfill each decade? I honestly don't know the answer. If you do, please share with the class.

April Showers

Actually, we should be so lucky as to enjoy some rain this month. Despite a few late storms, the National Weather Service records that San Francisco has gotten about 73% of its usual precipitation this season, and San Jose, 60% (and Los Angeles, 18%… wowch). Whether or not it's truly global warming, it's at least a reminder that the Golden State truly has a mediterranean climate, whose bone-dry summers begin about now and can last well into November.

To make sure your plants have the water they need — no more, no less — set your automatic irrigation system on a regular schedule. Unfortunately, your utility bill is about to become a two-pronged source of pain: you will see a spike not only in water usage but also in electricity, the power your irrigation valves need to open up and let that water through. (Ironically, water-thrifty low-flow systems need longer operating times, further increasing your electric bill.)

Short of replacing your new landscape with rocks, there are a few things you can do to stretch your water budget a little farther. First, waste as little as possible: water before sunrise, when the air is cool and calm, and adjust any spray heads to prevent overspray onto hardscaping or structures.

Second, encourage deep, drought-resistant plant roots by watering less often — only every three to five days — but for longer times. And help keep that water from evaporating by mulching with fir bark or compost, two to four inches deep.

Finally, and this is the big one, consider using plants that require less water to begin with. You don't need a "California native" garden to save water: plenty of gorgeous, non-native trees, shrubs, and perennials can get by with much less water than you might imagine. (If you would like suggestions for some un-thirsty plants that would be perfect in your garden, just let me know.) Lawns are a different story: they are, by nature, resource hogs. But unless you truly need a turfgrass lawn — for kids to play on, or for polo competitions — I can recommend some great alternatives that will be just as easy on your eyes as they are on your water bill.

Surviving our hot, dry, long summers actually is not difficult; but since only 2% of the world shares our climate, it does require some creativity. Start thinking now about how you might reduce your water needs and usage — and keep your fingers crossed for a few April showers to prolong the inevitable.

Bringing It All Home

The recent debate over at GardenRant about the virtues and vices of artificial turf has kicked into high gear a project I take very personally: developing my own yard.

I've taken my own advice and lived with the place as-is for a full year now: observed the way the seasons play with the land, taken my time developing a design, and wonder of wonders, not adopted too many orphan plants without digging the holes first. But of all the decisions I've had to make, the play lawn is the hardest.

One point conspicuously absent from the GR discussion is the suitability of artificial (or for that matter natural) turf as a play surface for children. Glib comments such as "If you can't grow a real lawn, give it up and move to a condo!", "I say ditch the whole lawn thing and plant lettuce," and "I'd rather have no lawn than a fake one" obviously were written by folks who don't have active children.

Much more sensible are the perspectives of Bay Area designer Michelle Derviss and avid plantsman Max W, who deftly points out that "What most people from summer rainfall areas fail to realize is that a lawn is a priori artificial in the rest of the country. Of course, all lawns are by definition artificial whatever the local rainfall patterns because they only exist by human intervention -- artifice."

But I digress, which is emblematic of exactly what I've been doing with our own yard: doing everything except pulling the trigger on natural or artificial. A biosystem and water bills? Or conservation and petrochemical manufacturing? According to the Irvine Ranch Water District down south, a typical installation of about 750 square feet of synthetic turf — yep, that's me — "can conserve approximately 22,000 gallons of water per year." Holy worm castings! The UC Davis Lawn Watering Guide confirms it, and at my current utility rates, that's about $1350 a year.

Probably because artificial turf is a newer invention, there tend to be lots of these sort of statistics available touting its advantages. I figured the Turfgrass Producers International would be equally biased in the other direction; but unfortunately, the strongest doubts they can cast on their competition run along the lines of, "What gases would be released into the atmosphere in the event of a fire on the artificial surface?" and "What are the health concerns related to the ingestion of ground rubber particles that takes place from sliding face-first on the surface or dropping and re-inserting a particle-covered mouth-piece onto the field?"

OK, I'm being a little rough on the TPI guys. But seriously, why aren't there any objective comparisons out there? Perhaps it's because neither product is objectively better than the other, only better for you. Assuming you need a turf area, is the only suitable location in shade? Is the artifical turf you're considering made with recycled materials or new? Does it require crumb infill? What kind? How much water will living grass require in the same location (and don't forget the electricity for holding those irrigation valves open, and gas or electricity for the mower, and fertilizer)? And so on, ad infinitum.

Obviously I'm not as well informed on this issue as I should be. So as I continue my education, you'll be the beneficiary. Of course, if you can shed any light on this whole damn quandary, please (please!) feel free.

How Dry We Are

From San Francisco Chronicle writer Glen Martin:

This season's scant rainfall doesn't yet mean we're in a drought -- but it's starting to feel that way. San Francisco is on track to post its fifth-driest January since 1850.

So far, San Francisco has recorded only 0.65 inches of rain compared to a normal rainfall of 4.72 inches. … And California as a whole is just as parched. Most crucially, the Sierra snowpack -- which provides Californians with most of their drinking and irrigation water -- has only 45 to 60 percent of its normal water content, depending on location. And it's not improving.

"The snowpack is declining," said Dan Gudgel, a meteorologist with the National Weather Service. "Every day that goes by with no precipitation puts us further behind with less prospect of catching up."

That's because California typically gets most of its precipitation in January, February and March, Gudgel said. Worse, no significant storms are headed this way.

Martin goes on to note that, while comparisons to the reservoir-draining droughts of the 1980s and 1990s may be premature, "The state's population is much larger now and would be harder-hit by a severe drought."

I was struck just a couple of weeks ago by how low the Lexington Reservoir, near Los Gatos, still was; and couldn't help but wonder what a drought might do to my business. Would homeowners clamor for water-wise makeovers? Or sit on their hands while their pretty flowerbeds and lush lawns became withered and crisp? Should I be in the business of green lawn paint?

Mostly, though, I was reminded of the wisdom of designing with "unthirsty" plants and low-flow irrigation systems, and the necessity of educating my clientele that we are, after all, a Mediterranean climate—meaning the next drought has every right to manifest this year (no matter what El Niño says). Are you ready?