I love mulch. If I had a mantra, it would be something along the lines of ‘when in doubt, mulch.'
Whatever the need — controlling weeds, less waterings, preventing erosion, keeping the soil temperature even, improving soil —mulch is the answer.
Usually it’s the dead organic layer that I’m talking about — bark chips, eco-mulch, or chopped leaves.
There are times though, when those mulches just don’t cut it. A partially planted bed, or a newly developed planting bed with only edger and soil in place are examples. Perhaps the plants are going to arrive next month, or next spring, the reason doesn’t matter. Leaving that soil exposed is a guarantee that weeds will become the matter.
If you’ve got lots of planting still to come, an organic mulch can add to the planting time as it will need to be pulled back to allow for both the hole itself, and a place to pile the soil.
A temporary live mulch is a great solution.
The idea is similar to the use of cover crops and green manures used by farmers and vegetable growers. In the urban context, though, it is a temporary solution for one growing season. Nothing is going to be permanent, and no timed ploughing will be required.
Ideal plants are leaf lettuce, peas, and nasturtium. Simply broadcast and gently ‘rake’ over them with the backside of the rake. This is not the time to obsess over recommended spacing and planting depth. Keep them moist until germination.
Do not thin them unless they are choking each other out. A dense planting will offer some serious competition to the weeds.
A nice added bonus is the visual component they add. Leaf lettuce gives a surface flush of bright light green or red; peas offer an interesting convoluted course texture; and nasturtiums add staccatos of colour — intense reds, yellows, oranges.
Nothing wrong with grazing on a bit of the lettuce. Pick so as to keep the soil covered and reseed if necessary.
Peas can also be harvested. Remove the plants with peas still attached, and reseed.
In a particularly large area, pumpkins are an option. They love to grow and will spread their tendrils of huge glorious leaves for several feet. Keep them trained or they’ll clamber up the fence, the shed wall, anything they encounter. Talk about a mulch with some life to it!
Carla Keast has a master’s degree in landscape architecture and is a Winnipeg-based freelance landscape designer. She can be reached at firstname.lastname@example.org.