Here is a question that came to the gardening advice team
Q: I planted a cover crop in my community garden plot and left it longer than I should have. There are now weeds mixed in with the cover crop blend. I’m not sure what I should do. If there are weeds mixed in with the beneficial plants I’m guessing I shouldn’t turn the plants under to decompose? Appreciate any advice.
A: It’s great to hear you planted cover crops in your community garden plot. Planting cover crops provides nutrients to the soil and helps with disease and pest management as well as improves water penetration and retention.
- In preparation to turn the garden bed, we recommend first removing any large weeds.
- Turn over the garden bed so that the cover crops and weeds can be turned back into the soil to decompose, adding organic matter and nutrients.
- Keep a close eye on the garden bed for any weeds that may pop up and remove them. This way it will be easier to identify the plants that are weeds from the plants that you intentionally plant and to efficiently remove them.
What About Flowering Weeds?
Fortunately, from the picture it looks like most of the weeds have not reached flowering stage and will not produce seeds, which means that by turning the weeds into the soil it should not spread more weeds. Many weeds are also relatively good cover crops, in the sense that they have deep root systems which help to break up the soil and protect the soil from erosion or being washed away. Weeds also attract beneficial insects and attract beneficial pollinators.
This is the most efficient way to prepare the bed for planting and to benefit from the cover crops in the bed despite there also being weeds in the mix.
Grasses Amongst the Cover Crop
It would be wise to pull any of the grasses that have gone to seed. The other grasses, if not gone to seed, could be cut and turned under with the rest of the green plants or pulled out completely. Some grasses reproduce by spreading out under ground and you will want to remove those grasses regardless of any visible seeds. These kinds of grasses are easy to spot because when you pull them, they will have long runners trying to set up new roots and branches under the soil. Other grasses will come out as a clump.
Tend Beds Sooner Rather than Later
Generally, you are on the right track to pull the flowers that you do not want and be careful not to spread any unwanted seeds around when doing so. It's early in the season, so perhaps that will not be an issue as long as you tend to the beds sooner rather than later. By mid- to late spring, if left unattended, you will have quite the menagerie of wanted and unwanted plants.
For additional information on weed management:
https://ipm.ucanr.edu/QT/landscapeweedscard.html
For a helpful weed photo gallery:
https://ipm.ucanr.edu/PMG/weeds_intro.html
For more information about cover crops:
https://ucanr.edu/sites/covercrops/
Good luck and happy gardening! :-)