Late-summer gardening

Cut back perennials – soon

Though daytime temperatures may still be soaring, nights are cooler. And that's the first signal to your plants to become dormant for winter. "Perennials like mums and irises are starting to show signs of stress, and you may be tempted to cut them way back. But leave them as long as you can. You want to keep the goodness in your plants for as long as possible while they still have their green colour," says Gord Nickel, host of Global Television's

Get Up And Grow

. Cut them back at first frost to avoid fungus growth.

TIP: Don't cut back blooms on plants such as Echinacea, hydrangea, Black-Eyed Susan and decorative grasses. They'll be dried out and colourless, but they add a little something to your garden in winter.

Caring for your lawn

The warm sunny days and cool moist nights of late summer make this a good time to top dress or lay sod in any patchy areas. "It's also a good time to fertilize. Choose something with high nitrogen content," says Sarah Beckon, a horticulturalist for

Toronto's Allweather Landscape

. Beckon and Nickel also suggest aerating in high-traffic areas where the ground feels hard and the grass isn't doing well. Punching out small holes in the turf will relieve compaction and allows nutrients to travel more freely. Adding some course sand to the lawn after aeration stops re-compaction of the soil.

TIP: By next spring, you may forget where things are planted, so take this opportunity to take photos, or makes notes about your garden while its summer appearance is still fresh in your mind. Or use nursery tags to mark the spots.

A little TLC for your trees and shrubs

Like the squirrels and chipmunks, trees are now storing up nutrients for winter. Give them lots of water, especially trees that are newly planted or trees that have been "browning out" over the summer, says Beckon.

"It's also a good time to do some minor pruning to remove branches that are diseased or dying, before it gets too cold," says Nickel. Because trees and shrubs are storing energy, you shouldn't be cutting off big branches.

TIP: Plant new trees and shrubs now – the warm days and cool nights make for great conditions. Just be sure you have at least six weeks before the ground freezes.

Putting your bed – to bed!

Start with a little soil amendment – improve the quality of your soil by adding a little decomposed manure or compost on top of your bed. Beckon explains: "It protects your plants, keeps the soil in the beds over winter and gives your garden a natural fertilization." You may also want to add a little winter protection: "There's lots of debris around due to the falling leaves. It's a breeding ground for fungus, so clean up the waste and protect your plants with mulch," advises Nickel. "As you remove annuals, replace them with hearty fall plants such as ornamental kale or cabbage, fall mums and icicle (winter) pansies," says Nickel. These will fill in the empty spots and give your garden a colourful fall look. "Leave your pansies in the ground – they'll come back in spring," suggests Beckon.