Tame Winter Weeds Naturally
Whether you regard weeds as reliable helpers or mortal enemies is a matter of perspective. Keeping them from taking over your garden or a natural area nearby is a matter of technique. Metro’s Natural Gardening Expert Carl Grimm showed us how to identify, beat and/or eat our gardens’ weeds – organically, of course.
Many annual weeds common in our area in early spring are actually edible: bitter cress (also known as “shot weed” for it’s explosive seed pods), purple dead nettle and chickweed are a few examples. All are easy to pull by hand or cut with a delta hoe or hula hoe. Since annual weeds grow from seed, flower, make seed and die within a year, the key to keeping them from returning stronger is to get them before they produce their seed.
Biennial weeds like common mullein, common mallow, and foxglove typically live only two years. They grow through one warm season and winter as a small plant then shoot up a flower stalk and produce seed during the following warm season. These can be hand-pulled fairly easily or cut with a delta hoe or hula hoe when small.
Perennial weeds like dandelion and quack grass are much harder to control because they develop long roots that live for years. The best bet for keeping these at bay is to pull as much of the root out as possible, and “never rip and run!” Always either mulch over, spread seed or plant a plant in the bare spot left by the weeds.
Mulches are great for keeping weeds down and for reducing water needs, protecting and improving the soil. Wood chips, bark, and filbert shells tend to last longer than compost, but don’t typically improve the soil as quickly as compost. Compost is good for mulching veggie beds and annuals. Spread mulches about 3 inches thick for best weed suppression, but don’t pile it against stems of plants, as this can cause disease problems. For pathways, use cardboard or landscape fabric underneath and consider a stone mulch like quarter-minus basalt gravel for longer lasting weed suppression.
Moss is considered a weed by some, despite how nice it is as a year-round groundcover in shady areas. On pathways, however, it is a slipping hazard that can be removed most easily by scraping and scrubbing with soap and water before the weather warms up and dries it out. In the lawn, consider leaving the moss since it is not really a problem in most cases. However, if you need soccer-playing-quality turf, you may want to scuff with a thatch rake, add lime and grass seed and top-dress with weed-free compost, then prune overhanging branches to make your turf thrive more than your moss.
Some weeds are a serious problem because they invade and take over our local natural areas, or cause serious problems for agriculture. Herb Robert (a.k.a “stinky Bob”) is an annual invasive weed that is easy to pull by hand. Just be sure to mulch over or plant the area you pull!
Metro offers great resources for local gardeners to learn more – simply call 503-234-3000 for your free publications or to be connected to an Oregon State University Extension Service for expert advice.
For Metro natural gardening program information visit oregonmetro.gov/garden.