The hot, dry days of summer are just as stressful for plants as for people – maybe more so. Whereas we can reach for a cooling drink from the refrigerator, plants that are rooted to the ground often depend on the kindness of gardeners to get them through dry spells. And as well-meaning as we may be, sometimes our watering techniques can leave plants high and dry.
One common irrigation method is to turn on the sprinkler during a sunny afternoon. But, as much as one-third of the water can be lost to evaporation and that's one-third that's not reaching your plants. Watering early in the morning is less wasteful, but an even better way is to forget the sprinkler and use a soaker hose instead. It looks like a regular hose, but a soaker hose has many tiny holes that allow water to slowly percolate onto the ground, so you can leave it on for two or three hours without the water pooling and running off. Snake it through your flowerbeds or circle it around your trees to deliver moisture at root level where plants really need it.
"If you have the space, place the soaker hose a few feet away from the trunk of a tree and wind it outward in concentric circles that go beyond the edge of the canopy so that the water reaches the feeder roots," says Janet McKay, executive director of Local Enhancement & Appreciation of Forests (LEAF) in Toronto.
Once the moisture is in the ground, the goal is to keep it there. The best way to prevent it from evaporating due to drying winds, for example, is to mulch the surface of the soil with a thin, two to four centimetre layer of composted pine, shredded leaves or cedar mulch. Not only does it act as a permeable barrier against wind, but mulch moderates soil temperatures, too, causing less stress for the plants in your garden.