When you feel hot on a bright summer day, there are several things you can do: You can sit under the shade of a tree or maybe go inside for a while. A drink of ice water sure helps. And an ice cream soda is even nicer! But what do you think a plant does when the air is hot and the sun is even hotter? It can't move, so it does something else. It gets rid of the excess heat by transpiring moisture. In other words, it perspires. When a plant starts to get hot in the sun, the water inside absorbs the heat and moves to the surface of the leaves, where it evaporates. This way the heat is continually given off. On very hot days, of course, a plant can use up a lot of water just staying cool, which is why watering the garden becomes so important in summer.
Now in ordinary gardens, roots can often go down deep enough to get water even when the soil seems quite dry on top. But containers are too small for that, so most container gardens must be watered every day. Small flowerpots might even need water twice a day. If your garden is a large tub or half barrel, the soil will be deep enough so that you would never need to water more than once a day.
How do you know when a plant is thirsty? Well, for one thing the leaves begin to droop. When they haven't enough water inside to keep them firm, they simply go limp. If they are left like that too long they will shrivel up and die, but generally a good watering quickly freshens them up.
Sometimes a plant will droop even when it has lots of water. This happens in the middle of the day when the roots can't suck up water as fast as the leaves are sweating it out. Don't worry - as soon as it turns cooler later in the day, the leaves will stop drooping. But if the leaves are drooping in the morning or evening when it is still moderately cool, then you know for sure there isn't enough moisture in the soil.
There are some other things you can do to keep a plant comfortable in summer. One of the best is to mulch the soil. A mulch is a sort of blanket that goes on top of the soil between the plants. It is usually of shredded leaves, or straw, peat moss, or even newspaper. Garden centers sometimes sell bags of mulch. A very attractive one you can sometimes get this way is buckwheat hulls.
An easy mulch you can make yourself is shredded newspaper. Wet the paper thoroughly and tear it into thin strips or small pieces. While it is still wet, spread the paper about half an inch thick between the plants and water it again so that it settles down nicely on the soil. You can leave it just like that, or you can pretty it up a little by spreading peat moss or buckwheat hulls over the top.
The mulch is an insulation, so it keeps the soil cool by keeping out heat. It also stops the soil from drying out too fast. Another advantage: It stops the weed seeds from sprouting, too.