Many of us move to the Valley of Sun from other places and don't understand how the desert climate changes the way we plant vegetables and flowers. Plants that grew back home may not grow here, so follows are some helpful tips to make gardening easier.
Sunny area plant solutions
Not all plants that grow in the sun are cacti. There are many varieties of shrubs and grasses that need full sun, which is their preferred micro climate. The majority of full sun plants in Arizona are drought tolerant, low water-use plants. These should be planted with regard to the sun's position in winter or summer. These include Lantana, Natal plum, Yellow bells, Oleander, Roses, Rosemary, Fountain grasses, Desert Bird of Paradise, Justicias, Cassias, African Boxwood, Agaves, Yucca, Sages and more. Most full sun plants can tolerate some shade, but the bloomers will have fewer blooms without the sun. Most trees must have sun. There are also many annual flowers that prefer sun, such as Vinca, Wave Petunia, Rudbeckia, Lisianthus, Angelonia, etc., for spring/summer. Annuals that prefer sun in fall/winter include Petunias, Snapdragons, Alyssum, Calendula, Geranium, Pansies, etc.
If a plant doesn't have enough sun, it will elongate and stretch seeking the sun. It will have a weak cell structure and flop over.
Shady area plant solutions
One problem that occurs frequently with small-lot homes is that we have areas of deep shade, especially in the wintertime. Because the sun is lower on the horizon, the north side of the house won't see direct sun for months. When you design or renovate a landscape, take this micro climate into consideration and select plants that tolerate large amounts of shade. Great plant choices for shady areas include Pittosporum varieties, Jasmine varieties, Ligustrum, Tropical Bird of Paradise, Gardenia, Euryops, Aloes, some Ferns, Euonymus, creeping Ficus, Day Lily, Turk's Cap, Japanese Boxwood and more. All plants need a minimum of eight hours of sun or high light. So the selection of upright mid-sized shrubs and ground covers for shaded areas can add a lot of color in tough-to-plant areas. Annuals that can do well in shade include Begonias, Coleus, Caladium, Viola, etc., for fall/winter and Celosia, Impatiens, Sweet Potato Vine, etc., for spring/summer. Don't put arid region sun plants in shady areas. The arid region plants need full sun or they will struggle and die.
Also be aware of water usage in shady areas. In the winter they need less water because they have lower evaporation due the low ultraviolet light. Change the water or you can kill the plants with too much water. Temperature (heat units) has the largest effect on the consumptive use of water.
You will notice that grass, primarily Bermuda grass, does not grow well in shady areas. Rye grass does grow well in a shady area but does not tolerate the intense ultraviolet light in the summertime. Grasses like St. Augustine and some fescue varieties will tolerate more shady conditions
Vegetable planting solutions
The micro climate for vegetable gardens is full sun year-round under all situations. For example, corn has to have full sun or it will elongate to the point it will look like a skinny reed grass and never set tassel or develop corn to be pollinated.
In corn it even involves spacing. If it is too close together it will not have enough ultraviolet light and heat units.
One of the biggest mistakes in the Valley is to put tomato plants in full shade where they don't get enough sun to stimulate bloom and grow property. If they have too much shade they will elongate and go to vegetative growth.
It is the same with peppers, cucumbers, corn and okra. In the intense heat of the summer you can shade tomato plants with a partial shade cloth to protect from the strong afternoon west sun. Our tomatoes are still blooming and healthy in the sun with some afternoon shade from the blackberry bushes.
Cauliflower, broccoli, cabbage (cold crops) can take more shade and less light but they grow slower and you will have a longer time to harvest. Timing is everything with vegetables because you have short days in the winter and long days in the summer.
You have to have short daylight cycle onions for winter and you can't use long day onions that are grown in the northern regions of the U.S.
A quite common mistake is to plant tomatoes in the winter such as Romas and they don't have enough light and heat units to provide for proper growth of the tomato.
The same goes for summer. For instance, carrots can't take the heat units in the summer.
You are wasting your time, money and energy if you don't use the correct veggies in the correct location.
• Gary and Sharon Petterson own Gardener's World and Gardener's Eden Landscaping in Phoenix. Reach them at (602) 437-0700. For the nursery, call (602) 437-2233 or visit www.gardenpro.net, and for landscaping, visit www.gardenersedenaz.com.