After a wet spring, gardeners have had to do a lot of watering this summer thanks to near-drought conditions.
Emma Erler, host of Homegrown NH and lead horticulturist at Kirkwood Gardens at Squam Lakes Natural Science Center, has also been busy with the hoses, and has some suggestions for keeping your garden hydrated.
She says the first step is to keep track of how much water the garden is receiving naturally.
“I think everyone should have a rain gauge in their garden,” she says. “It does not need to be sophisticated; a straight sided container will work with a good old fashioned ruler. So after a rain event, with just a tin can and a ruler, you can measure exactly how much rain fell.”
Erler says most of the plants we have in our gardens need about an inch of water a week in order to thrive, and often we don't receive that much rain.
Many gardeners use a sprinkler to water, and when you use it matters.
“My preference with a sprinkler is always to water in the morning,” says Erler. “That allows the foliage to dry out before nightfall. If leaves stay wet overnight, they're going to be much more likely to become infected with a fungal disease.”
And just as you measure rainfall, you also want to pay attention to how much water you're putting down with the sprinkler. Each sprinkler emits water at a different rate, so you can measure with your rain gauge to calibrate how long to use your sprinkler.
Erler prefers drip irrigation. “It's the least wasteful,” she says. “It keeps the plant foliage dry because it's delivering water right where it needs to be, right to the plant roots.”
A drip irrigation system takes some time investment to start. A simple drip hose, which exudes water along its length, can be purchased at most garden centers or hardware stores, and it's highly mobile. You can thread it among your plants and hook it up to a regular garden hose. It can even be buried under mulch.
“We have an extensive permanent drip system at Kirkwood Gardens,” she says, “but drip irrigation makes it a bit harder to measure exactly what the output is. I like to dig right down into the soil with my trowel and see how far down that water has reached. Then I can do the calculation by figuring out how long my system has been running.”
Erler says it’s crucial to make sure she’s watering deep enough to reach the plant roots.
If you see a plant wilting, Erler recommends determining if the soil is damp, by feeling the soil with your fingers. “If it's damp, it could just be that the sun is stressing that plant out a little bit, and it'll perk up as soon as it ends up in the shade again. But if that soil is dry, then it's drought-stress and you need to water.”
See you in the garden!
Homegrown New Hampshire is a collaboration between Squam Lakes Natural Science Center and NHPR.
