It’s June and the driest month in the desert. As temperatures soar above 100 degrees, many vegetable gardeners call it quits and decide they have harvested all they can. This isn’t true, however, if you apply man-made shade techniques that imitate nature.
The keys to extending your growing season are water, mulch, and shade.
Although water isn’t shade, it does have a cooling effect on your plants. Don’t change the amount of time you have been watering. If it was working well for you in February through May, it will work well for you in June and July. What you DO change is the frequency. The key is to keep the soil moist but not soggy. For example, if your tomatoes crack, it is probably because your soil is drying out in between watering. You want to add to the number of days you water your vegetables. How long you water will depend upon your soil and the plant needs. Test your soil frequently by putting your finger into the soil to your knuckle. If it isn’t moist, water more frequently. Also, water in the early morning hours when evaporation is lower. Early morning watering also cools down the roots before the heat hits. Check your emitters and sprinklers at least a couple of times a week to make sure water is still getting to your plants. I found a gusher in my garden this morning, which meant that plants down the line weren’t getting their usual water. In this heat, it might take only a couple of days for the plants to wilt beyond recovery.
Mulch will provide close-contact shade for your soil. You should place three inches of mulch on your garden beds. It retains the water and keeps the soil surface cool and moist. For raised beds, straw works best. In-ground gardens can be covered with straw or fine wood chips. Don’t use hay because it comes with seeds and you will find hay stalks growing in your garden! I have even had some hay stalks grow from my straw because hay was stored next to the straw where I bought it. Replenish your mulch because it will compress over time.
The jury is still out as to whether you should work mulch into the ground after each growing season or remove it. I remove the straw and throw it into my compost pile where the heat in the pile can kill any bacteria that may have developed. Wet straw and leaves will sometimes grow mold on the underside. This is great for a hot compost pile but not for tilling into your ground.
NATURAL & ARTIFICIAL SHADE
We are so short of shade in the desert. If you place a deciduous tree on the west side of your garden, you are already ahead of the game. It will shade your garden from that hot west sun in the summer, but since it loses its leaves in the winter, you will get the full sun advantage for the colder months.
If you don’t have trees to protect the west side, you can do the same with tall sunflowers or trellises of beans or cucumbers (both heat lovers), or you can build low tunnels over your garden rows or raised beds. A picture of one of mine is to the right. In the summer, I put 40% shade cloth on it (30-60% is good). In the winter, I put clear plastic when I want to warm it up during the day. At night, I use winter garden blankets when the temperature drops below 35 degrees. The low tunnels stay up year-round in my garden because of how I use them, but they can also be removed when not needed.
Walls are also helpful, but be careful. They can offer shade, but they also reflect heat. Wood fences will provide shade but won’t create heat problems. Most of us have block walls, however, because of the durability. These will reflect heat, which is helpful in winter but can create hot micro-climates in the summer.
By applying these techniques, I will still be harvesting tomatoes in mid-July then again in December. After investing so much money and labor in my garden, I really appreciate the extra food produce!