Protect your garden during a heat wave

I’ve been watching our weather forecast closely and am very concerned. Here in Spokane, a heat wave begins this Saturday, with a high of 101 degrees F. On Sunday, the forecast shows 105 degrees, and on Monday and Tuesday, the National Weather Service believes we’ll be up at 110 degrees. That is scary.

I just received an email from a gardener, asking what she could do to protect her vegetable plants. I don’t blame her for being concerned. We’re probably all feeling pretty anxious about this heat wave. Here’s what I suggested since I’m sure others might be wondering about it, too:

What to do during a heat wave:

1. Keep the plants well-hydrated. They will definitely need more water than usual. We are watering our veggie garden in the morning and in the afternoon around 4 p.m. in an effort to protect them from the heat. The important thing is to avoid overwatering the plants, so be sure to keep an eye on how they’re doing.

2. Place a thick mulch (about 2″) onto the surface of the soil to help it retain moisture, if you haven’t done so already. We use grass clippings because we don’t treat our lawn with herbicides such as Weed ‘n Feed. Shredded leaves also work well for this purpose, as does partially-decomposed compost from your compost pile.

3. I have been using a shade cloth over my lettuce and broccoli beds to keep them a little cooler. Although my lettuce bolted the other day so it is finished growing. I plan to start some new seedlings but there’s no point in planting anything until the temperatures get back to normal. I’m going to avoid using floating row cover because it will trap the heat. But if that’s the only thing you have handy, I would suspend it over the plants. Then leave the sides up a bit so there will be some good air circulation.

4. If you’re growing anything in containers, keep an eye on them. Remember that even under normal circumstances, they will dry out more quickly than in-ground plantings. Be sure to check on them throughout the day and poke your finger into the soil, down to your 2nd knuckle. I have found my containers need to be watered twice a day.

5. If you’re growing peas, they won’t be happy with the heat wave and will shut down. Be sure to pick all of the ripe ones ASAP! If you still have lettuce growing, you’ll want to pick it now because it will definitely bolt to seed and become bitter.

6. The person who contacted me was worried that the leaves on vegetable plants will burn. I don’t think peppers or tomatoes will burn, as long as you keep the plants hydrated. Of course, I’m not sure I’ve ever experienced 105 degrees (or more), so I’m not sure. The one thing I wouldn’t do is to water the leaves of the plants in the heat of the day. That will burn and shock the plants very easily.

7. Remember your bird friends by making sure they always have fresh water on hand.

If you are also dealing with unusually high temperatures for your area, consider doing the above if you haven’t already. But the MOST important thing is to keep yourself safe. Don’t spend a lot of time outside in the heat. Wear a hat and sunscreen if you do need to take care of something out there, and stay hydrated.

What NOT to do during a heat wave!

• Don’t mow your lawn! Yes, I know it will look ugly but the taller blades of grass will shade the roots. That will help them get through the hot weather.
• Don’t fertilize your plants. They can’t handle it or “process” it in a normal fashion. Wait until the weather goes back to more normal temperatures.
• Don’t install new plants. They can’t handle the heat!
• Don’t prune your plants. Same reason!
• Don’t divide your plants or move them… yes, for the same reason. Everything will wait for us to get through this.