Weed of the Month: Scotch broom

In May, it is covered with bright yellow pea like flowers. The flowers mature to flattened seed pods that contain up to a dozen seeds each. Dried pods will crack and pop open in mid summer and eject the seeds a short distance. A single plant can produce well over 20,000 seeds that last in the soil for more than 30 years (some estimates are as long as 80 years).

Scotch broom easily invades disturbed sites, natural areas, dunes and forest lands. This weed displaces native and beneficial plants and smothers tree seedlings, hampering reforestation efforts. It causes loss of grassland and open forest habitat. Flowers and seeds are toxic to humans and most animals. Scotch broom creates highly flammable fuels increasing wildfire danger. Control costs for this weed exceed $47 million annually.

Scotch broom can be controlled by various methods depending upon the severity and the location of the infestation. Plants can be pulled when they are small and dug when they are larger. They can be cut between flowering and seed production and stumps can be treated with herbicides (check with the OSU Extension Master Gardeners for advice).

Do not put plants with seed pods in compost or yard waste. They should be bagged and placed in the garbage. Do not burn plants with seed pods; when exposed to fire, its seeds burst from their seed pods.

If you are looking for a yellow blooming bush for spring color, rather than planting Scotch broom, consider the native Tall Oregon Grape or the ornamental Forsythia hybrid.

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Conservation Districts are local, non-regulatory, public agencies charged with assisting landowners and residents with responsible natural resource management and stewardship. Hood River Soil and Water Conservation District in Hood River, Wasco County Soil and Water Conservation District in The Dalles, and Underwood Conservation District in White Salmon are available to assist with a variety of natural resource issues, including soil health, water quality, fish habitat, wildfire risk, forest management, noxious weeds, pollinators, wildlife, livestock and agriculture.