Lowest-maintenance landscaping: garden beds for GTA yards

The lowest-maintenance landscaping for most GTA yards is a garden bed planted closely enough to cover its own soil, with a clean edge and a layer of mulch. Beds that turn into a weekly chore usually weren’t planted badly. They have too much bare soil, no real edge and a few plants that hate the spot they’re in.

Weeds need light and open ground, grass spreads in from the lawn, and a struggling shrub needs watering every summer. Fix those and the bed asks very little of you.

The steps below are the same whether you do the work yourself or have it done as a garden bed and planting job.

Why is a planted bed the lowest-maintenance landscaping?

Once the plants fill in, they shade out most weeds and there’s nothing to mow. What work is left in a garden bed comes from four places:

1. Weeds growing in bare soil between plants.
2. Lawn grass creeping in along the edge.
3. Plants that need extra water, spraying or replacing because they’re in the wrong light or the wrong zone.
4. Plants that outgrow the space and need cutting back several times a year.

Everything below is about cutting down one of those four.

Which plants need the least care in Ontario?

The plants that need the least care are the ones that suit your light, your soil and the winter. Start with the winter.

Natural Resources Canada puts Markham in plant hardiness zone 6b on its current map (1991–2020 climate data), up from 6a on the older 1961–1990 map.

A plant rated for zone 6 or lower should get through a normal winter here. One rated zone 7 is a gamble.

Match the plant to the light

Watch the bed for a full day in summer and count the hours of direct sun. Toronto Master Gardeners sort beds like this:

Around a house, beds on the south side usually get the most sun. Beds on the east or west side often get only morning or afternoon sun, which tends to put them in part shade.

The north side of a house or fence usually lands in that last group. A sun lover in shade tends to get leggy and weak, and a shade plant in hot sun can scorch. Either way you end up replacing it.

Start with native plants

Landscape Ontario’s guide to native plants says they’re better adapted to local climate and soil and more resistant to local pests and disease. That means less time and money to keep them going.

Some reliable picks from Ontario sources:

Skip the groundcovers that never stop

That last row matters more than it looks. Credit Valley Conservation says goutweed spreads aggressively through underground stems (rhizomes) and by seed, and can take over a garden and sneak onto a neighbour’s property.

Periwinkle and lily-of-the-valley are sold as easy groundcovers for the same reason they cause trouble: they don’t stop spreading.

The Ontario Invasive Plant Council’s Grow Me Instead guide for southern Ontario lists both as invasive, along with goutweed and English ivy, and suggests plants to grow instead. Lily-of-the-valley, for one, spreads by rhizomes into dense colonies.

How close together should you plant?

Close enough that the plants will cover the soil within a few seasons. The spacing or width on a plant tag is roughly its mature spread, so plants set that far apart will only touch once they’re full grown.

Planting a little tighter than that fills the gaps sooner, as long as you’re not crowding shrubs that will need cutting back every year to fit.

Plant in groups of three, five or seven of the same thing instead of one of everything. Landscape Ontario’s native planting advice makes the same point: clumps look more natural than single plants scattered all over.

Fewer kinds of plants also means fewer different care routines to remember.

Think about the size the plant will be in five years, not the size of the pot. A cedar or a lilac planted a metre from the house will need shearing every year to stay off the siding.

Pick a shrub whose natural size fits the space and it rarely needs more than a light trim. Our guide on when to trim hedges and shrubs in Ontario covers timing for the ones that do.

How much mulch keeps the weeds down?

A layer 5–10 cm (2–4 in) deep of wood or bark mulch. Cornell University’s weed science guidance says that depth alone can give adequate weed control, because a thinner layer lets light reach the weed seeds.

Piling on far more wastes mulch, and Cornell warns that excess mulch can kill shrubs and trees. Keep it off stems and trunks, where the Morton Arboretum notes it traps moisture and invites decay.

Our mulch guide covers how much to buy, when to put it down and how wide a gap to leave around trunks.

Mulch won’t fix every weed problem. Cornell says it mainly suppresses annual weeds, the ones that sprout from seed each year, by blocking the light they need.

Is landscape fabric worth it?

For planted beds, usually not. Cornell’s guidance on weed barriers lists the problems:

• It works for a relatively short time.
• It does little against perennial weeds.
• New weeds root into it, which makes them harder to pull.

It also snags on tools, and taking out old fabric around established plants is slow, messy work.

Washington State University extension horticulturist Linda Chalker-Scott points out that any organic mulch or soil on top of the fabric speeds up weeds colonizing it, and that weeds eventually grow on top of and through it. Mulch rots down into a thin layer of soil, and seeds that blow in grow right there.

You also can’t add or move plants without cutting holes in it. Mulch over well-weeded bare soil does the same job without the cleanup later.

Why does edging matter so much?

Lawn grass spreads sideways, and without a clear line it creeps a little further into the bed every season. A crisp edge also makes a bed look cared for even when it hasn’t been weeded in a while.

Our garden bed edging guide compares the options and which ones survive an Ontario winter.

On our sod, edging and mulch project an interlock border edge separates the new sod from the mulched beds.

Common mistakes

• Planting into soil that still has grass roots and perennial weeds in it. They come straight back up through the mulch.
• Buying plants on looks at the garden centre without checking the light and zone on the tag.
• Leaving wide gaps between small plants and filling them with mulch forever, instead of planting enough to cover the ground.
• Piling mulch against stems and trunks (“mulch volcanoes”).
• Laying landscape fabric and then wondering why the weeds are growing on top of it.
• Choosing a fast groundcover that turns out to be invasive.
• Skipping water in the first summer. Many groundcovers are only drought tolerant once established (the City of Guelph’s list says this about several), so water new plantings deeply until their roots take hold.

When should you plant a new bed in Ontario?

Plant in spring, once the soil has thawed and dried enough to work without turning to mud, or in early fall.

Fall planting has the advantage of cooler weather, but plants need time to root before the ground freezes, so earlier in the fall is safer than later.

Mulching and edging can be done any time the ground isn’t frozen. They fit naturally into a spring cleanup or a fall cleanup.

Doing it yourself or getting help

Tidying, edging and mulching an existing bed is a good weekend job.

The heavy part is starting a new bed or rescuing one that has gone wild: lifting sod, digging out weed roots and old shrubs, moving soil and mulch by the barrow, and hauling the debris away. That’s the part most worth handing over.

Our weed treatment and clean-up project shows a bed along a fence that was overgrown with weeds and long grass, cleared back to the hostas and covered in fresh mulch.

If you’d like us to look at yours, call or text (437) 684-2535, or read more about our garden bed, planting and mulching service. We work across Markham and nearby, including Richmond Hill and Stouffville, and quotes are free.