It’s HOT out there!

You’ve probably noticed it’s really hot and have heard some dire warnings about the heat index. Your plants have noticed, too. The most obvious need when dealing with heat is WATER. However, getting the water right for your plants can be tricky. Watch out for these deceptions:

  • Wilting. Chances are your plants are wilting because they’re thirsty, but plants will wilt both when they have too much water and when they don’t have enough. Wilting only indicates there’s a problem, it’s not enough to diagnose the problem. Also, be aware that tomatoes routinely wilt in the heat of the day, but that is just their mechanism for dealing with the heat and doesn’t necessarily mean they need additional water.
  • Dry Soil Surface. Because the sun is baking down on it, the surface of the soil may be dry, but underneath there may be plenty of water. I have been fooled by soil that is dry and cracked on the surface only to discover mud underneath. Push your finger, a screwdriver or a moisture meter down into the soil several inches to be certain. The heavy, clay soil which makes digging so challenging in this area has an amazing ability to retain moisture below the surface. The soil in potted plants can be just as deceptive with the top dry and yet damp underneath that dry layer. Over watering is just as detrimental to plant health as drought.

Consider these strategies to make your watering more effective:

  • Water slowly. When the soil surface is dry, water will often roll right off. To keep the water on your lawn instead of running down the gutter, try setting your sprinkler timer to water for 5 minutes per zone then run the program which waters that zone 3 times over the course of the night rather than running each zone for 15 minutes all at once. My sprinklers run in the early morning, starting at about 3:00 am when the wind is typically calm and it is the coolest time of day to prevent evaporation. If you’re using the hose to water shrubs, bedding plants or container gardens, water everything briefly, then go back and water everything again more generously. With these strategies, the soil has a chance to absorb the water.
  • Use drip irrigation. Drip irrigation (rather than spray) is popular for good reason – it delivers the water slowly, consistently and directly on the soil surface.
  • Fertilize gently. Fertilizers that are applied to the leaves are likely to burn the plants in high temperatures – avoid these. Apply slow-release fertilizer pellets to the soil rather than spraying plants. If you have a fertilizer unit on your drip irrigation system, now is a good time to add fertilizer. Use up to 4 tablespoons water soluble plant food to the canister. Cool-season turf grass does not need fertilizer now; it can be fertilized again in cooler weather.
  • Give your plants a quick spritz. Considering running your sprinklers on the lawn or in a shrub and perennial bed for just a couple of minutes late in the afternoon (around 4:00). This increases the humidity around the plants and helps them recover from the heat of the day.

Finally, our best strategy for dealing with the heat is simply patience. Some plants take a break from flowering in the heat of the summer, but they’ll bloom again when the temperatures cool. Some vegetables (squash in particular) will drop their flowers because they don’t have the energy to produce fruit in this heat. Other plants, like spinach and lettuce, “bolt” and send up their flowers and seeds in a last effort to reproduce before they expire in the heat. The turf grass frequently turns yellow-brown, but it isn’t dead, it’s just dormant and will return to green when both the air and the soil temperatures drop.

For you and I, the gardeners, the best strategy is to work outside in the early morning and in the evening when it’s cool; drink plenty of water; use sunscreen; and wear a hat. (I prefer an embellished cap!) If you have questions or concerns about your plants in this hot weather, feel free to contact me. Happy gardening!