Garden plants wilting? Expert provides watering advice during Sask. heat wave

As a heat wave continues in much of Saskatchewan, gardeners are wondering how much water their plants need to survive.

Gardening expert Lyndon Penner tells CBC Radio's The Morning Edition that the best way to cope is to prioritizeyour watering routine.

"We all have plants that we've lost to drought," he said. "I have killed things because I planted something, I had to go away for the weekend, I come home, and you could draw a chalk outline around it."

Penner is in Saskatoon this week for the University of Saskatchewan's annual Hort Week, kicking off Sunday with a talk on sustainable gardening.

Not everyone has the resources for constant watering, so in Saskatchewan's climate it pays to choose your garden plants carefully as to how much watering attention they will need.

"Nobody wants to be enslaved by a plant," Penner said.

Vegetables and container plants are particularly demanding "You can't go away for summer unless you have someone to water for you," said Penner but once temperatures are past 30 C, he said it's safe to assume all your plants are thirsty.

"When it gets to be that hot, those pores on those plantsthey will be open and they will be losing water."

And when plants get heat stressed, he said, they're more susceptible to disease and pests.

Different plants, different watering needs

How often you'll need to water depends on the type of plant and how moisture-retentive the soil is, said Penner.Vegetables and container plants will need watering daily, but a well-established perennial in a mulch bed may only need water as little as once a week.

"Drought-resistant" plants need love, too, he added.

"'Drought resistant' means a plant can survive dry and hot if it must;it doesn't mean that that is what that plant is longing for. Unless it's a cactus, you're going to have to water when it gets this hot," he said.

When it comes to watering priorities, he said containers and the vegetable garden should be watered above all other things, and perennials should be hardy enough to withstand some neglect if time managementis an issue.

How you water is important

"Go through really slowly and make sure everything gets a good, deep drink," Penner said.

A good, deep drink every two to five days is better than a tiny bit every day, "which is what a lot of people do," he said. Watering is also best done in the early morning or late evening, when it's cooler.

"I've seen people turning on sprinklers in the hottest part of the afternoon and that's bad, bad, bad," he said.

Besides losing a lot of water to evaporation, water droplets on leaves in the heat of the sun can work like magnifying glasses, resulting in scorch marks. High-spraying lawn sprinklers also don't do much for a garden.

"The water doesn't do any good six feet off the ground," he said. "It needs to get to those plants' roots."

If your garden starts looking sad and droopy, he said he's seen wiltingplants "revive miraculously" after a good rain or a deep watering.

"Plants have been doing this for millions of years without us. Nowhere in nature did sprinklers evolve."

He added if all else fails, you can always buy more plants.