How to Help Your Flower Garden Beat the Heat
Summer is off to a hotter than average start. Most of the country is already getting more than its share of heat and humidity, often with record-setting temperatures.
While we can take refuge in the shade or an air-conditioned room, the plants in your flower garden have nowhere to hide. Here’s how you can help them weather a heat wave.
1. Keep Watering at the Top of Your To-Do List
Hot weather can make even the simplest gardening chores unpleasant. Give yourself permission to let most of your to-do list wait for cooler temperatures. Focus on the single most important task: watering.
Plants perform at their best when the moisture level in the root zone is as consistent as possible. When the soil gets too wet or too dry, the fine, hair-like projections on the ends of the roots can be damaged. Though these root hairs will regrow, doing so requires energy that would otherwise be used for flower and fruit production.
2. Check the Soil Before You Water
The best moisture meter is your index finger. Before you begin watering, wiggle your finger down a few inches into the soil. If it feels dry, it’s time to water. If not, it’s probably fine to skip a day.
Seedlings and recently planted perennials, shrubs and trees are an exception to this rule. The soil around these plants should be kept consistently moist until they have established a good root system. This will take a couple weeks for seedlings and perennials, and a couple months for shrubs and trees.
3. Take Time to Water Slowly
When the surface of the soil gets dry, it sheds water like a duck’s feathers. The solution is to start slowly and gradually build up to a thorough soaking. Begin with a relatively quick pass to moisten the surface. Then come back in soaker mode to do the real watering.
When you water with a watering can, it’s easy to know many gallons you have applied. That’s harder to gauge with a hose-end sprayer. Consider counting to slow yourself down. Use the sprayer to fill a watering can and count how long it takes to get a full gallon of water. Then when you’re watering, you can count the seconds to make sure you’re going slowly enough to deliver a satisfying drink.
4. Water the Soil, Not the Foliage
Whether you use a sprinkler, watering wand, drip irrigation or soaker hoses, try to focus your attention on the root zone. Spraying a plant’s leaves may cool it down, but little of that moisture will actually get to the roots where it can be absorbed.
As you’re watering, visualize where the roots are actually located. They usually reach outward just as widely as the plant’s foliage and may extend more than a foot beneath the soil surface.
5. Avoid Overwatering
Plants need oxygen just as much as they need water. When soil gets super-saturated, the air between the soil particles is forced out and plant roots can suffocate. Container plants are particularly vulnerable, which is why it’s important to use a good growing mix that resists compaction. If you have saucers under your pots, be sure to dump them often so they don’t get filled with water.
Most plants grow best when they get about an inch of water per week. As a general rule, it’s best to water deeply and less frequently. Letting the soil dry out a bit allows air to refill the pore spaces.
6. Know The Difference Between Thirsty and Hot
We’re not the only ones who wilt in the heat. Lots of plants will wilt on a hot day, but this doesn’t necessarily indicate that a plant needs water. In hot weather, plants wilt to reduce transpiration and conserve moisture. At the end of the day they usually perk up again. If they don’t, they’re definitely thirsty.
Well-established perennials, shrubs and trees are remarkably resilient to heat and drought. Learn to recognize which plants are dramatic wilters (tomatoes, hydrangeas and sunflowers to name a few) and which ones only wilt when they really need water.
7. Use Mulch to Conserve Moisture
Covering the soil with a thin layer of organic mulch will help reduce evaporation and minimize runoff. Good options include compost, shredded leaves or bark and pine needles. But don’t overdo it. If the mulch is too thick, it can work against you by absorbing water and preventing moisture from reaching the roots.
Another way to conserve water is to avoid watering during the middle of the day. If you save that job for morning or evening, less moisture will be lost to evaporation. It will also be a much more pleasant task for you!
Keeping your plants fed is almost as important as keeping them watered. To learn more, read: How and Why to Fertilize Your Plants.