Keep your garden cool during triple-digit heat

Well, we knew our cool weather wouldn’t last. Triple-digit days are on their way – just in time for a red-hot Fourth of July weekend.

According to the National Weather Service, the Sacramento region can expect highs of 100 to 110 degrees this weekend, peaking on Saturday, July 1.

“An Excessive Heat Watch is in effect from 11 AM Friday to 11 PM Sunday for the Valley and foothills,” tweeted the NWS Sacramento office on Tuesday morning. “These are the highest temps we've seen this year! With this happening during the holiday weekend, NOW is the time to prepare: Have a way to stay cool & hydrated!”

Thursday could be the first of several triple-digit days. Friday’s forecast calls for 103 in downtown Sacramento and 105 on Saturday. That’s almost a 30-degree leap from Sunday, June 26, which recorded a high of only 76 degrees.

This first real heat of summer could take a toll on your garden. Your new transplants aren’t used to these extremes.

Before that first 100-degree day, prepare your garden – and yourself – for the heat ahead:

* Stay hydrated! That applies to both you and your garden. Water early in the day – before 8 a.m. if possible – to cut down on evaporation.

* Cycle and soak. Water needs a chance to soak in, especially if you have clay soil. Otherwise, it will run off (and down the drain) instead of reaching roots. Run your irrigation for a short period. Wait an hour or two. Then, run your system again. The water from the second cycle will reach deeper than the first.

* Mulch, mulch, mulch! A layer of 3 inches of straw, wood chips, dried leaves or other organic material will keep soil and roots cooler while conserving moisture.

* Shade sensitive plants and developing fruit on tomatoes, peppers, eggplant and squash. Your harvest can get sunburned. Protect from intense afternoon rays with temporary shade such as burlap draped over trellises.

* Wilting can be normal. Some big-leafed plants such as squash may seem to wilt every hot afternoon; that’s OK. They recover overnight. It’s when they’re still wilted in the morning that it’s a problem.

* Check the soil before you water. It may look dry on top, but still have enough moisture in the root zone 6 inches below the surface. Plants can suffer from too much water (especially in containers) as well as not enough. But remember that containers dry out quickly in heat -- any hanging plants especially may need to be watered twice daily.

* Prioritize your watering. Deep-water trees and shrubs, which are your landscape’s most valuable and slowest-growing plants.

* Switch to drip. Drip irrigation puts water where plants need it – at the roots.

Heat is often on the minds behind Sacramento Digs Gardening. Here are links to several past columns with heat-related advice: