Fall a good time to plant in desert
By Becky Purvis, Maricopa Master Gardener
While gardeners in other parts of the country have put their gardens to bed for the winter, desert gardeners are gearing up for their favorite planting time.
Desert fall planting grows beets, broccoli, cabbage, carrots, cauliflower, celery, chard, cilantro, cucumbers, dill, endive, kale, kohlrabi, all kinds of lettuce, leeks, onions, peas, radishes, spinach and turnips. There even is a brief window to plant cucumbers, summer squash and tomatoes.
When planting in a new garden, select a good location. Most vegetables need six to eight hours of direct sun daily. While it’s easy to add shade cloth for relief from summer sun, it’s impossible to create sun in an area that gets too much shade.
When we moved into our new home, my first inclination was to put the garden where I thought it would look nice. This would have placed it next to the back fence. Unfortunately, my back fence is on the south side of the yard and casts a 6-foot shadow through the entire winter. That location would have been fine for a summer garden, but wouldn’t have worked at all in the winter.
Observe your yard and think about which areas get sun and shade during the different seasons.
If the area you have chosen has Bermuda grass, you’re going to have to kill it before planting. The Desert Botanical Garden (www.dbg.org) has an excellent list of articles on its website. If you go to “Desert Gardening Guides” and scroll down to “Miscellaneous Gardening Topics,” you’ll find an article called “How to Remove a Bermuda Grass Lawn.”
One of the advantages of container gardens is they are moveable. When it’s hot, place the containers where they will get afternoon shade. When it cools down, move them to full sun. If a freeze threatens, throw some old blankets over them. It’s easy and inexpensive.
Just about any container with holes in the bottom for drainage will work for gardening.
Larger pots are preferable because they give plants room to grow and the additional soil protects the roots from temperature fluctuations. Five-gallon nursery pots work well. You can drill holes in the bottom of a five gallon bucket and plant a tomato. Be creative. Last spring I was given a small plastic wading pool, so I cut a bunch of holes in the bottom and used it to grow squash, peppers and basil. One caution: Be sure the container has never held toxic chemicals that might leach into the soil and contaminate your vegetables.
PLANTING IN RAISED BEDS
Raised gardens are easy to plant and easy to take care of; there’s very little digging and no weeding.
Mel Bartholomew’s book, “Square Foot Gardening,” has revolutionized the way people approach gardening. He suggests building a garden no more than 4-feet wide so you can reach the center without having to step on the soil. It should be at least 6-inches deep, but I.ve seen gardens raised as much as 3 feet for people who have back problems. Be aware it takes a lot of soil to fill a garden that deep.
Using a shovel to loosen the ground beneath the raised bed will give plant roots additional room to grow and improve drainage.
Wood and stone are most commonly used to edge raised beds. Only untreated wood is safe to use, since pretreated lumber and railroad ties can leach toxins into the soil. Untreated lumber will crack and warp within a year or so, but by using a food-safe wood preservative like linseed oil, even inexpensive lumber will last for years.
Bartholomew recommends using equal proportions of peat moss, vermiculite and bagged compost to fill containers or raised beds. Bagged potting soil also can be used.
Unfortunately, desert soil lacks the organic matter needed for successful planting.
Apply 2-3 inches of compost and/or well-rotted manure. If drainage is poor, the University of Arizona Cooperative Extension recommends adding 3-5 pounds of soil sulfur per 100 feet. Fertilizer containing nitrogen and phosphorus also can be used.
Work all of this into the top 10-12 inches of soil and water well. Wait until it has dried to a crumbly consistency to plant.FALL VEGETABLES
Arugula, beets, broccoli, cabbage, carrots, cauliflower, celery, chard, cilantro, cucumbers, dill, endive, kale, kohlrabi, all kinds of lettuce, leeks, onions, peas, radishes, spinach and turnips can be planted through January.
Garlic can be planted in October and onions in October and November.
Most vegetables grow well from seed planted directly into the garden. A few, such as broccoli, cabbage, cauliflower and tomatoes, are easier to grow from transplants.
To get the most out of limited space, you may want to plant according to Bartholomew’s book. Divide your garden into 1-foot grids with string or narrow wood lathe and plan your spacing according to the planting guide on the back of the packet. If the packet of radishes said to thin plants to every 2-3 inches in one direction, space them the same distance apart in the other direction. There’s no need to have rows if you won’t be walking in your garden.
Don’t plant your entire garden at once. Plant a square foot of radishes, spinach or lettuce one week, then plant another square foot a week or two later. That way you’ll get a continuous supply of radishes, spinach or lettuce, instead of having them mature all at once.
When you pull all the plants out of one square, add a little compost and plant something else. Why leave valuable garden space empty when you can plant another crop? Keeping your crops planted in a grid makes it easier to replace them without disturbing neighboring plants, and the string helps you stick to your plan.
Broccoli, cabbage, carrots, radishes, chard, kale and spinach don’t mind a light frost, but cover when a freeze is expected. One day I may buy frost covers for my garden, but so far I’ve stuck with a stack of old sheets and blankets. Poking a few stakes in the ground keeps the weight of the blanket from flattening the plants.
Planting guides and gardening resources can be found online at the University of Arizona Cooperative Extension at Extension.Arizona.edu/Pinal.