I hate weeding perennial gardens, in fact any weeding, with a passion; after more than 30 years in the gardening business, I never met a weed I liked. And I confess I’ve developed a bit of a “rant” about plants that want to take over my garden in defiance of this gardener’s wishes. So what’s a gardener to do?
Weed Control Strategies
I probably sound like a broken record on this one but here’s the hard data. A 4-inch layer of mulch is going to reduce weeding by over 90%. A 3-inch layer by over 80% and a 2-inch layer by 60%. You can take those numbers to the bank.
A steady covering of mulch improves the soil on an ongoing basis as it decomposes – reducing or eliminating the need to fertilize the perennial garden.
It averages out soil temperature swings in late fall and early spring so plants roots don’t get growing too fast (to be knocked back by late frosts) and allows the fall roots to store energy from the soil even after the tops have been knocked back by frost.
It reduces moisture use by preventing soil evaporation. In drought periods, this can make a difference between the plant surviving and dying.
Cautions with Mulch
You don’t often read this part but here’s the deal. If you cover the crowns of most plants, the extra moisture will rot the crown out over the winter. So do not cover the actual plant with mulch – back the mulch away from the central crown by about 6-12 inches around the crown.
Gardeners in the wet areas of the continent – mostly the west coast – where summers are damp and hot are going to find mulch is a perfect haven for slugs. And plant rot. So gardeners out there can’t blindly assume advice for the northeast is going to work for them. I note that a wet summer in the northeast will also increase slug damage on plants.
Quite frankly, mulch is perfect for my well-drained soils but if you’re gardening in those areas you may want to experiment a bit before launching a full mulch programme
A bit of work every week to get the grass (the major perennial weed that does the most damage) is essential. There’s no getting around this – you either do this or you’ll regret it shortly.
As one of my famous asides, I note that perennial gardening is “gardening” – it’s not low maintenance as many books will tell you; there’s one heck of a lot of work involved to keep these beds clean and looking good. You can “cheat” a bit here and there but once you allow grass into the beds, you’re looking at a full renovation digging. Sad fact of life.
What about Chemicals?
Well, I’m an organic gardener but if I wasn’t I’d still have trouble with chemicals in the perennial garden.
There is no single chemical that will kill all weeds in the garden and leave the plants alone.
And to make things even more interesting, any single chemical will kill some perennials and allow others to survive. And there isn’t enough research out there to tell you which is which.
What about Roundup? Well, it kills what it touches so you can’t just walk around spraying it willy-nilly in the garden. And the latest research coming out on this stuff is quite scary from an organic / environmental point of view.
We’re left with mulch and tools
So What About Tools?
Again, the single best tools on the market are the hands of the gardener. And the knees. Put the knees in contact with the soil and get the hands working and you’re in great shape for weed control.
Tools are almost useless if you mulch. The mulch stops the tools from working effectively other than simply hand tools (see below)(
I use a hoe-mi for the majority of my weeding in all parts of the garden. It comes in short-handled and long-handles (I prefer short because I use it for planting, weeding and darn near every other cultivation chore) And the point on this tool does get through the mulch and into the soil to loosen up roots.
I can’t stand those small hand sized garden forks and mini-shovels. Waste of time in my toolkit given the versatility of the ho-mi.
There are other specialist hoes such as a circle hoe that advertises itself as being able to get right next to plants without damaging the main crowns (true) and other forms of dutch hoes (winged weeder) that advertise as being effective in general gardening (true) but don’t work well in the mulched garden.