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When in drought… water your plants slowly, in the morning

Image of mother and daughter watering plants
Watering restrictions throughout the B.C. south coast and Vancouver Island include some city and municipality bans on watering lawns, and often limit watering of plants, vegetables and trees to watering by hand, with a can or a nozzle.

With water restrictions in effect, let grass go dormant and keep your plants healthy

Posted by Rob Klovance

Don't worry about your lawn. Water your veggies, plants and trees slowly, and in the morning. Worship your shade trees (and think about planting one or two this fall for future summers).

And get used to the heat, because it's the new normal.

These nuggets of advice (and more below) are courtesy of BC Hydro vegetation maintenance manager Gregg Hallaway, a man who knows a thing or two about plants and trees. And for the record, he doesn't have a shade tree in the yard of his North Vancouver home.

"No, I don't, but my neighbour does," says Hallaway, who oversees vegetation issues around BC Hydro's distribution power lines in the Lower Mainland. "There's a nice big Douglas fir and a hemlock in my neighbour's yard that provide me with great shade in the late afternoons and evening."

Shade is a valuable asset during the Big Drought of 2015, which, combined with well-below-average winter snowpacks on the south coast and Vancouver Island, has led to escalated watering restrictions. Check your local city or municipality website regularly for updates on those restrictions, and follow a few of the following tips to get you, and your plants and trees, through what's threatening to become a more common weather pattern here in B.C.

A ban on lawn watering in your area? Don't worry

Hallaway took his family on a recent vacation during our July drought in southwest B.C. and didn't bother arranging for someone to water any of his plants and trees — not even the vegetable garden — during the drought. He returned to find the vegetables still alive — "My wife was very happy about that!" — and wasn't the least concerned about the browning lawn.

"Lawns basically go dormant at these times, and they'll come back as soon as the fall rains start," he says, suggesting that when the rains arrive, a lawn can green up within as little as a couple of weeks.

"At BC Hydro, we get complaints when we're replacing a power pole and we leave a new pole on someone's boulevard and it leaves that long brown spot," he adds. "As soon as the pole's moved and the rain gets a chance to soak into that spot, the grass comes back quickly.

"It's just like when a kid leaves a toy in the backyard, a Frisbee upside down for instance. You move it and by the time you cut the lawn you don't even know it's there."

Getting to the root of watering basics

Stage 3 watering restrictions in places such as the City of Vancouver include bans on watering lawns but allow for continued watering of flowers, vegetable gardens, decorative planters, shrubs, and trees.

The change is that sprinklers or soaker hoses are prohibited — you can only water these plants by hand, using containers, a spring-loaded shut-off nozzle — or through drip irrigation.

Stay on top of watering restrictions in your city or municipality and stick to two fundamentals: Water slowly, and in the morning.

"Watering in the morning is always the best," says Hallaway. "When the temperatures are lowest, the plant can actually utilize the water it's taking in."

When you water in the evening after a hot day, water can be lost through an accelerated "transpiration" process in which plants and trees send water collected by the roots up through the trunk and branches and into the leaves where the water is released back into the atmosphere.

"It's like the plant is sweating — it's losing that water to transpiration when it could have used that water in the morning for its metabolism and storage and other processes trees and plants do," he says.

Water slowly, allowing the water to sink deeper into the soil. That promotes root growth deeper into the ground and can pay off in the longer term as roots near the surface dry out more quickly and have less access to water as it evaporates from the soil during drought conditions .

Take care to water beyond the middle of a plant or trunk of a tree — overwatering at the base of a potted plant in particular can cause root rot. Slower watering throughout the "root zone" — basically the soil area up to two times outside the "drip line" circumference, where rain would drip off the canopy of a plant — provides the best chance for all roots to get in on the hydration.

Most mature trees and plants need to be watered no more than once a week. Younger plants need more attention.

Cedars have a tough time, but do their best to survive

Cedars can struggle in droughts and often start turning brown to the point where they appear to be not just suffering, but dying. Some cedars will fall victim to the current drought, while others will survive by diverting water/nutrients from less efficient or dying branches.

"It's a defence mechanism," says Hallaway. "It recognizes it's facing a drought situation, and will selectively cut off supply to older leaves or often less efficient leaves toward the interior of the tree, to reduce their exposure to the drought."

Plan for the future with shade trees, drought-resistant species

A few days before we talked, Hallaway ran into a federal fisheries officer who confirmed what Hallaway has been hearing from meteorologists and other experts on climate and its impacts. This unusually hot, dry summer, is a sign of things to come.

"We're going to get longer, hotter, and drier, summers," he says. "We should be planting trees that are more suitable for those conditions."

Hallaway says rhododendrons, particularly the small-leafed variety, are among the more drought resistant options. In general, he says, trees with waxy leaves tend to be more drought resistant.

And there's nothing quite like thinking ahead and planting a shade tree or two. Select a deciduous tree and plant it outside the south side of your home — its leaves will keep your home cooler in the summer (and cut down on your cooling bill), but after dropping its leaves in the fall, will allow the sun to warm your home when it gets colder in the winter months.

"I don't have a tattoo, but if I had one, I'd want it to read 'Planting the right tree in the right place,'" says Hallaway, with a chuckle.

Rob Klovance is managing editor of bchydro.com.