With the nice weather we have been experiencing, it is time to start uncovering and caring for our asparagus beds. Here are a few tips:
If you haven’t removed last year’s growth from asparagus plants, now is the time. Asparagus comes up around the first of April. Asparagus benefits from a fertilizer application in early spring.
You should fertilize according to a soil test or add one to two pounds of a 10-20-10 or 11-15-11 fertilizer per 20 feet of row before growth starts. If a soil test shows that only nitrogen is needed, apply one pound of a 16-0-0 product or half pound of a 30-4-5, 27-3-3 or similar fertilizer per 20 feet of row.
Most of these high nitrogen fertilizers are lawn fertilizers but will work well for this purpose if they do not contain a weed preventer or weed killer.
Incorporate lightly with a tiller or rake in fertilizer before spears emerge. Fertilize again with a high nitrogen fertilizer at the same rate suggested above after the last harvest. The fertilizer should be watered in with 1/4-inch of water.
The best time to control weeds in asparagus is early spring before the asparagus emerges. A light tilling (or hoeing) that is shallow enough to avoid the crowns will eliminate existing weeds. Many gardeners like to mix in organic matter during the same operation.
Herbicides can be used before asparagus emerges. Glyphosate (Roundup, Killzall) will kill weeds that are actively growing, and the pre-emergence herbicide trifluralin can be used to kill weed seeds as they germinate.
Trifluralin is found in several products, but not all of them list asparagus on the label. Those that do have asparagus on the label include Miracle-Gro Weed Preventer Granules and Monterey Vegetable and Ornamental Weeder. Mulch can also be used to keep weeds from invading. Please read and follow all label directions.
No herbicides can be used during harvest. The end of harvest presents another opportunity. Remove all fern and spears and apply glyphosate (Roundup) to control virtually all of the weeds present. Past the harvest season and after regrowth of the asparagus, options are limited.
Products that contain sethoxydim can be applied to asparagus to kill grassy weeds. Sethoxydim has no effect on broadleaves including asparagus. Two sethoxydim products available to homeowners and labeled for asparagus are Monterey Grass Getter and Hi-Yield Grass Killer. With broadleaves, the only option is to pull them and look forward to next year.
For more information on asparagus, contact the Ford County Extension Office! Have a great weekend!