Spring is when most of us finally get around to mulching. The weather settles and the beds look tired after winter, so a fresh layer goes down over a weekend. Then the first heavy storm comes through and a good chunk of it ends up on the lawn or washed across the path. Nine times out of ten that’s an edging problem rather than a mulch problem. It pays to sort out the border first, whether that means putting in something like ShapeScaper garden edging or resetting an edge that’s already there.
Why spring is hard on garden beds
Couch and kikuyu start pushing runners sideways into any bed that lets them as soon as the soil warms. Spring storms tend to arrive in short, heavy bursts that shift loose material around, usually right after the bed’s been topped up and is sitting higher and fluffier than it was all year. The edge is doing a lot more work than it was in July.
Plenty of edges were never set up for that. Bricks laid on top of the soil get nudged out of line every time someone steps on them. Older borders sink a little each year, and you don’t really notice until the mulch starts washing straight over the top.
Set the edge before the mulch goes down
If you mulch first, you end up raking it all back to cut the line, then spreading it out again. Bare soil also shows you the bed’s real shape. That’s easy to lose once everything’s covered
A few things to check while the ground is clear:
- The line itself. A garden hose laid on the ground is the easiest way to test a curve, and leaving it there for a day so you can look at it from inside the house helps more than you’d think.
- Height, measured against the finished mulch level rather than the soil.
- Junctions with paths and paving, since that’s where mulch almost always escapes first.
- Whether a mower wheel can run along the lawn side. An edge sitting close to lawn level saves a surprising amount of trimming over summer.
Picking a material that stays put
Timber looks lovely for a few years before it starts to soften in the ground. Once it leans, the mulch starts slipping past it. Steel and properly set masonry last a lot longer, and steel bends into curves while taking up almost no room in the bed. In a narrow border, that space counts. But fairly speaking, if an edge can’t hold its position, it doesn’t matter much how good it looked on day one.
Councils look at it in much the same way. The City of Greater Geelong’s garden bed standards for new developments expect edging to clearly mark the bed, keep the mulch in and stop lawn grasses and weeds creeping across from the turf. They also set mulch depth at 75 mm, which is a handy benchmark at home because it shows just how much loose material an edge has to hold back.
Keeping the mulch where it belongs
Once the edge is in, rake the mulch so it finishes a little below the rim rather than flush with it. That small lip catches most of what the rain tries to carry off. Keep it pulled back from plant stems as well. The same Geelong standard asks for this so stems don’t rot, and it’s good practice in a backyard too.
Top-ups through the season work better as thin layers than one deep load. It’s tempting to get the whole job done in a single go, but a bed built up gradually stays below the edge, while one heavy layer has a habit of creeping over it by Christmas.
After the first big storm, walk the spots where bed meets path. Anything that’s moved will show up there first.
Doing it once
An edge does most of its work when nobody’s paying attention to it, so it’s no surprise it gets left until last. Most people only notice it once half the bed is sitting on the lawn and the mower’s flicking it back onto the path. Sorting it out before you mulch this spring takes a day or two. Put it off and you’ll probably be raking mulch off the lawn every few weeks until summer, and by then the beds are thin enough that you’re back at the garden centre buying more bags to top them up.