How to make your yard and garden more drought tolerant
In a way, we’re parents and guardians to our gardens. We take pleasure in the nurturing of our grass, trees, shrubs and perennials, but it’s important to raise them to be independent. Ultimately, they need to be able to thrive without us.
That’s particularly true on the Prairies. “The central plains are known as a very harsh growing environment,” says Dan Tavernier, NAIT landscape gardener.
That usually means long, cold winters and short, hot summers. Some years, it means limited precipitation. To prepare plants for every eventuality, we asked Tavernier how to water to raise them right.
Pick appropriate plants
There’s a reason birch trees are dying across the province: they’re simply unsuited to long periods of Prairie drought. Tavernier’s advice: “Populate your landscape with native materials as much as possible” and choose those that will survive on rainfall alone. “Work with material that can sustain a fair amount of drought.”
For trees and shrubs, Tavernier suggests
For perennials, which can store water for tough times even better than woody plants
In general, “fuzzy foliage is often an indication of a drought-resistant plant,” says Tavernier.
It’s a lawn story
Tavernier likes lawns but dislikes using treated city water to sustain them. If a lawn serves no social function – as a place for kids to play or backyard barbecues – he recommends converting it to perennial beds.
Then toughen up what remains. Tavernier aerates in the fall for better water uptake when the snow melts. In the spring, he top dresses with well-composted organic matter to encourage root development and reduce evaporation. Spread just a centimetre or so. “You should barely see it after you rake it in.”
He fertilizes with a slow-release, nitrogen-heavy mix (Alberta soil, Tavernier points out, is already relatively high in root-boosting phosphorus). When he mows, he increases the length as summer progress, to about 7 or 8 centimetres to shade the roots from the August heat.
He never waters his lawn. “Turf can go dormant,” says Tavernier.
The goal with our gardens should be to water as little as possible. “You’re trying to eliminate any supplementary watering,” says Tavernier.
To help slow runoff and allow grass roots to absorb more precipitation, Tavernier recommends digging swales across the lawn. These mini trenches run perpendicular to the slope and are shallow enough that they don’t cause scalping when the mower wheels dip into them.
They’re also useful around trees and shrubs, dug out as circular depressions, just a few centimetres deep. Cover them with 7 to 8 cm of organic mulch (rocks can heat up and damage roots) to help reduce evaporation.
When water is the only way
If you can’t live without a lush expanse of green grass underfoot, “the rule is infrequent, deep watering rather than frequent, shallow watering” to promote root growth, says Tavernier. Apply 2 to 5 cm once a week, watering in the morning when it’s cool and wind tends to be lighter. This minimizes fungal infection caused by water sitting on leaves overnight.
As for new plants, don’t let them try to make it on their own. Like the lawn, thoroughly water once a week as well. Expect them to still rely on you, at least for a little while.
A note about pots
To reduce water consumption in pots and containers, Tavernier recommends using
- larger pots soil so stays wet longer
- a slow release fertilizer to encourage root development
- a potting mix that has a good ratio of mineral to organic soil, such as Pro-Mix