Grow what you will eat in quantities you will be able to use.
This is one of the simplest and most overlooked gardening strategies! Because of water restrictions on California farmers, it's likely that produce prices will increase sharply this summer. It will be more cost-effective to grow your own, provided you plant the appropriate varieties and amounts so that your harvest does not go to waste. (And if you do have excess, find out which local food banks will take fresh food to give away.)
As long as you incorporate a bunch of water-management strategies, the drought need not affect your choice of annual crops. Since this is the beginning of the dry season, however, I wouldn't plant fruit trees, brambleberries, asparagus, or other perennial crops that won’t produce a crop this year. They will be better off planted next fall or winter, once the temperatures cool down and the rains (we hope) return. Planted now, they would need extra water to get established and would need extra care to make sure they survived occasional summer heat waves.
Some crops do not need much water once they set fruit, such as dry beans, winter squash, and tomatoes. One of my neighbors at the community garden does not water her heavily mulched tomatoes (3-4 inches of mulch) after July 1. Restricting water improves the flavor of tomatoes. The flavor literally becomes washed out if you water them too much. When I've used less than an inch of mulch, I've generally watered tomatoes every 5-6 days.
Crops that do need regular water are worth growing as well. It takes less water to grow most backyard crops than it takes to grow the same crops on a farm and bring them to market, so growing your own is a valid water-saving strategy. I like to eat cucumbers and snap beans every day in season, and it doesn't take much space to grow enough of them.
Herbs are easy to grow and nice to have on hand. You generally need a small amount at a time, so growing them enables you to take only what you need and accent your food regularly with fresh herbs. Many of them do better when kept on the dry side -- not including basil and cilantro, which like water.
If there is one general rule for drought gardening, it is mulch mulch mulch. This has always been important in our summer-dry climate and is especially important this year. Mulch helps keep the soil alive, reduces evaporative losses, and cuts down on the amount and frequency of watering needed. I’ve used tree trimmings (usually aged in my paths a few months before applying to my veg garden), straw, and garden clippings (chop and drop) as mulch.
A close second general rule of drought gardening is adding compost, which increases the water-holding capacity of soil. I add it under the mulch or lightly raked in, rather than digging it in. I let the worms work it into the soil.
Don’t till. Preserving the soil structure in an established garden is an important way to optimize its water-holding capacity. I also use a humic-acid product to help build soil structure.
Don't overfertilize. Excess fertilizer stimulates new growth, which attracts pests and increases the need for water. Use low-number organic fertilizers or compost. In much of Santa Clara County, the wonderful clay soil needs only some nitrogen for good production. I add alfalfa pellets (from a pet store) in the bottom of the hole when I plant tomatoes, I make the occasional bucket of fermented comfrey tea to feed my plants, and that's it.
Water the surface, near the roots, rather than using sprays. I occasionally wash down the leaves, but when I'm hand-watering, I direct the water at the base of the plants. I use a water breaker, which delivers a gentle rain of water and does not disrupt the soil or damage seedlings. Watering only the root zone also cuts down on waterborne diseases, which commonly plague squash, cucumber, and tomato leaves.
Another alternative is drip irrigation (checked regularly for the inevitable leaks, clogs, and timer malfunctions!) or soaker hoses, which can be installed under a layer of mulch to further cut down on evaporative losses. Observe your drip or spray system in action to make sure runoff is not occurring. If it is, reduce the watering time, cycle it on and off so the water can be absorbed, or reduce the flow rate.
Watering early or late in the day also reduces evaporative losses.
I like to reserve outdoor watering primarily for edibles. if your ornamental plantings are not drought tolerant, consider whether you want to spend part of your water budget on them, or let them fend for themselves. Ornamentals also benefit from lots of mulch -- up to 4 inches within the drip line of existing shrubs and trees and 6-12 inches or more in unplanted areas. Hold off on replacing ornamentals or even planting drought-tolerant natives until the next rainy season. Every new planting will need to be coddled through the summer, and it makes more sense to spend time and a limited water budget on plants that offer a return.
If you’re starting a new vegetable garden, consider planting at ground level this year rather than building raised beds. The soil in raised beds will be a little warmer earlier in the season, but it will dry out faster than soil at ground level. In arid climates, sunken beds are used to retain as much moisture as possible.
Containers are a good choice if you don’t have a garden plot, but they will require regular monitoring and will use more water than plants in the ground. If you must use containers, consider a double-wall system (a smaller pot inside a larger one), a system such as the Earth Box or a do-it-yourself equivalent, or a structure where the containers wick water from below. One system features a row of containers sitting on a covered rain gutter, with a valve that fills the gutter when water falls below a certain level. And mulch them!
Other strategies include putting a bucket in the shower to collect water, or installing a greywater system to water ornamental plants and fruit trees (not edible crops).
copyright 2014 Tanya Kucak
