Drought Gardening

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How to Garden in a Drought: Think Like a Plant! May 2002 by Kathy LaLiberte

In times of drought it can be very difficult to make sure plants get the water they need to survive, much less thrive. With wells running dry, reservoirs running low, and water bans in effect in many areas, we have no choice but to minimize the amount of water we give our plants. So how can we keep them happy and healthy while using little additional water? Try thinking like a plant. If you understand how a plant gets and uses water, it's a lot easier and actually kind of fun, to figure out to how create and maintain a water-efficient garden.

All About Roots Most plants absorb very little moisture through their leaves. Almost all the water they need has to get absorbed through their roots. So the more roots they have, the more potential there is to find and absorb moisture. A well-developed root system with lots of little sponge-like root hairs is a plant's best insurance for survival in drought conditions.

For a plant to expand its root system, it needs to be able to push out into the soil. And to do that, it needs to be working in a loose, friable soil--not one that is hard and compacted. Gardeners can help out by breaking up hard-packed soil with a fork, and most of all, by adding organic matter. Mixing organic matter in with native soil particles loosens up the soil and makes it much easier for roots to stretch out in all directions.

Organic matter--such as compost, peat moss, and shredded leaves--works in two other important ways to help roots access moisture. Adding these materials will make your soil more loose and friable, so water that's applied to the soil surface won't run off but rather will move down into the soil 10 or even 20 inches deep.

Soil that contains a large amount of organic matter can also retain much more moisture. Imagine pouring a cup of water over a pile of small stones. Now think about pouring a cup of water on a clump of moss. When water is applied to soil with lots of organic matter in it, the water stays put and will be available to plant roots when they need it. One-hundred square feet of good, loamy soil can absorb about 90 gallons of water, whereas 100 square feet of sand can only absorb 60 gallons.

One last note about roots. Absorbing moisture is the task of the youngest, most tender part of the root system--the growing root tips and root hairs. When moisture conditions alternate radically between wet and dry, these root hairs get stressed and damaged. Covering the soil surface with a thick layer of mulch reduces water loss from the soil surface. Just as importantly, it also helps maintain a consistent moisture level in the soil to keep delicate root hairs healthy.

All About Leaves Plants can't absorb very much water through their leaves, but they do lose it through their leaves. In fact, 98% of the water absorbed by a plant goes out through the microscopic pores (called stomates) on the plant's leaves. This may seem wasteful, but transpiration is a necessary part of the plant's metabolic process of absorbing soil nutrients and exhausting carbon dioxide. Transpiration also helps plants cool themselves in hot weather.

There are several ways to minimize the amount of moisture your plants lose through their leaves. First, is to protect them from excessive sun and heat. Late-day sun is especially hot, so it's a good idea to provide your plants with a little shade. You can do this by making use of the trees in your yard, putting up a lattice roof over your deck plants, or just planting wisely so tall plants provide some shade for shorter plants.

Remember that droopy leaves on a hot afternoon are not always cause for alarm. In hot sunlight, some plants are able to close their stomata and reduce transpiration. It's a natural defense mechanism. Once the sun goes down and the air temperature begins to cool, the plants will resume their normal functions and the leaves will perk up.

Another important way to reduce moisture loss through your plants' leaves is to protect them from the wind. My garden is in a very windy location and I use a number of techniques to calm it. In the springtime, newly seeded beds get watered once, and are then covered with a spun polyester row cover. This cover keeps the soil surface from drying out and also protects the newly emerging plants from being battered by the wind. New transplants get the same treatment. Young plants are especially vulnerable to moisture loss because they haven't established enough of a root system to keep themselves hydrated.

For the last couple of years, I have been wrapping row cover fabric around the sides of my tomato cages and also around the mini-cages that I use for eggplant. The plants love this protection from the wind, and they thrive with very little additional water.

At my house, the prevailing wind is from the southwest, so I have installed a 3-foot picket fence along the western side of my cutting garden. Like most windbreaks, this fence protects an area about one to three times its height. (At three feet high, it shields about six to nine feet of the garden that lies to the northeast of it.) I find this part of the garden stays productive and happy without any additional water.

I have also planted shrubs and trees to create windbreaks in various places in the yard. In the perennial garden, I use tall, sturdy plants such as echinops and garden phlox to shield more tender plants from wind. In the Native Americans' traditional Three Sisters Garden, they used tall corn plants to provide wind and sun protection for the squash and beans growing below. I do the same in my own vegetable garden, using the tomatoes to shield the beans, and the sunflowers to shield the cucumbers.

The drought conditions of the past couple summers have been heartbreaking for farmers and gardeners in every part of the country. If you've figured out some techniques for beating the drought that you'd like to share with other gardeners, please write to me at: innovativegardener@gardeners.com

-- Anonymous, May 13, 2002

Answers

This is a great article, OG. I'll file this away for the next drought. At the moment, though, we Ohioans have more water than we need.

-- Anonymous, May 14, 2002

Glad to see an article like this that doesn't stress mulching. Sure, it helps keep the ground moist, but it takes so much more rain to soak past the mulch that you still have to hand water.

-- Anonymous, May 14, 2002

Where I live, it seems like drought hits every summer starting mainly around July, sometimes late June, and ending around October. I had thought about xeroscaping to resolve the issues but never liked the plants that I found. This place earns the name "Dust Bowl" yearly.

That is until I got the land. Some of the wildflowers that are growing are stunning! I'll try to take some pics of them if hubby didn't get them all cut down last night when he mowed. There are some white ones that sort of look like a snapdragon but aren't. I think that I may possibly set up an area with the wild weed flowers just so that I may enjoy their beauty.

I can't get away from the wind, so will have to try to find solutions for that problem.

Meemur,

I'd take some of your extra water if you could get it directly into my ground supply.

-- Anonymous, May 14, 2002


We have water laying on the gtound,,,, 5 inches in my measure gauge in less then 24 hrs... I love the water, but this is to the point the farmers are a month behind in planting. we are saturated up by the lake! and due for more rain tomorrow night into the week-end.

I am just concerned first they drown , the plants, they we will get a drought! never a happy medium!

-- Anonymous, May 14, 2002


apoc - read somewhere that a wind break, whether fence or hedge, can block wind to three times its height. I.e., I guess the wind goes up and over. I don't have this problem here so didn't take much notice of the article. Otherwise, I use tomato cages for my tall lilies, etc., once they rust and the foliage grows, they're almost invisible.

-- Anonymous, May 15, 2002


have another cigarette, OG. That article is the one above that you posted. LOL

-- Anonymous, May 15, 2002

I have a lot of plants inside waiting to be hardened off, but I can't do it until the rains and the winds subside. It may take a major shift in the jet stream to make that possible. Tomatoes are finally outside, and looking so vulnerable.

-- Anonymous, May 15, 2002

Mine, too, Brooks. This is the latest I've set tomatoes out around here and I'm still keeping the half-milk jugs handy in case the threat of hail looms again.

Get this! One of the weather mongers said there might be *WET SNOW* on Saturday night around Lake Erie (SAR's area).

If we hadn't had such a weird year weather-wise, I'd be giggling and wondering what they're smoking, but I'm not laughing this year.

-- Anonymous, May 15, 2002


yep, I heard that too, meemer!!!

-- Anonymous, May 16, 2002

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