Edmonton

Let sleeping bugs lie, gardening expert says

Gardeners keen to clear their freshly-thawed lawns of any rotting autumn rubbish may want to resist the urge for a little while longer.

'If you need an excuse to not clean your yard for another week, now you have one'

Bumblebees are just some of the insects waiting to thaw out this spring. (Adam Wyld/Canadian Press)

Gardeners keen to clear their freshly-thawed lawns of any rotting autumn rubbish may want to resist the urge for a little while longer.

Lots of creepy-crawlies are still sleeping and your unkempt garden is a great place for a long winter slumber.

Leaving your leaves untouched is the environmentally friendly thing to do.

"If you need an excuse to not clean your yard for another week, now you have one," said Heather Proctor, a professor in the University of Alberta's department of biological sciences.

"It's for the good of biodiversity."

While butterflies and some other insects migrate south each winter with the songbirds, plenty of backyard bugs stay put — spending the winter burrowed down in old leaves, rotting wood or deep in the ground, below the frost line.

'Still sleeping' 

Some survive the sub-zero temperatures as eggs, larvae or pupae, while others make it through the winter as fully-grown adults.

But no matter how they withstand the cold, each species must wait until the spring weather is perfectly sunny before they crawl out of their hiding places.

Some insects, such as bumblebees, take longer to wake up than others. 

By manicuring the lawn too early, you could be sending some of your best pollinators — and most helpful predators — off to the landfill in droves, Proctor said.

She suggests waiting until the ground has been snow free for a couple weeks before getting to work with the rake. 

"I would say, don't disturb your wood pile, don't chop down standing stalks of stuff," Proctor said in an interview Wednesday with CBC Radio's Edmonton AM. 

"Leave them for a little while longer until the ground is really thoroughly defrosted." 

While ladybugs overwinter in large clusters deep in leaf litter, bumblebees prefer to burrow deep under old wood piles. Their solitary cousins will take shelter in the hollowed stalks of dead plants. 

You can create a safe haven for these insects by creating some heaps of leaves, wood and compost and leaving them undisturbed year-round.

"If you don't already have a brush pile in your garden, make a little pile of bigger sticks or an old stump and just put it in a corner," Proctor said. 

"Under the sticks and stumps, that's where the fertilized queen bumblebees will live underground. 

"You don't want to be killing off your queen bees because that's where all the subsequent generations of worker bees are going to come from." 

However, if there is a particular pest you wouldn't mind shipping to the landfill, now is a good time to put a dent in the unwanted population, Proctor said.

"Let's say you had a bad pest outbreak under your favourite apple tree. You can clean up the leaves that are under that tree, bag them up and send them off to be composted.

"Many of those flies or caterpillars could still be sleeping."