By George! - A Blog!

Here we are at the beginning of May and the night temperatures read in the sixties and the day temperatures are in the nineties.  One result of these wide figures is that our soil temperatures hang around 65 degrees which is decidedly cool for this time of year.  Most reference books stress the importance of watching soil temperatures for planting and sowing success. There’s a table of appropriate temperatures matched against the main crops in my book “Desert Gardening–Fruits and Vegetables”.  It’s worth looking at this table.

Surprisingly, gardeners who set out tomatoes some weeks ago are happy about their growth, which even includes flowering and fruit set.  Peppers and eggplant are not doing as well nor are the seeds of watermelon and cantaloupe.  Some seeds of corn are growing well, but not all. And it’s all related to soil temperatures.

Good gardeners know that the soil in June, July and August is going to be too hot for comfortable growth and they plan to use a vegetable mulch such as hay or straw to keep the hot sun from making the soil too hot.  They also plan to use some kind of shade cloth to protect the foliage and the flowers and fruit of eggplant, peppers, and tomatoes.  Other summertime crops such as melons, cantaloupe and squash can take all the sun that’s going and no special treatments are called for.

But meanwhile we need to care for the soil if we are to stay on schedule for summer crops.  The melons and squash need a warmer soil and it would detrimental to cool the soil down with a mulch at this time.

Keep the soil bare for a few more weeks in order to get good germination and growth of melons and squash and other summertime plants that enjoy hot weather.  After they have germinated and grown a little it will be time to put down the mulch.

The best mulch is alfalfa hay because it is usually free of weed seeds.  On the other hand, Bermudagrass hay usually carries lots of seeds–and no gardener likes to have Bermudagrass growing in their plot during the summer months.  It loves the heat!  Alfalfa hay adds nitrogen to the soil as it decays, so here’s another good reason to use it.  Other materials are wheat, oats and barley straws

This time of year we change the cooler pads in preparation for summer’s heat and the pads look quite suitable for the job because they are covered with mesh to hold them in a nice flat shape–but they are not to be used because they have accumulated salt from last summer’s operation, and salt presents a major threat to good plant growth.

The best way to use these straws is to break open the bale into flakes that are about four inches thick and lay them down like tiles on the soil around your plants  They will keep the sun off your soil, protect your drip irrigation tubing from thirsty birds, rabbits and squirrels, and smother weed seedlings when they germinate. At the end of the season, when you need to rejuvenate the soil in readiness for a fall planting, a mulch should be sufficiently decayed to enable you to easily rototill everything into the soil.

But don’t hurry to put down a  mulch until you measure the soil temperature with a thermometer and you know that summer is finally here.