Weeds will invade any bare or thin area in a landscape. Prevent invasions in new beds with good soil preparation. Keep weeds out with an integrated program that includes good growing plants, mulches, hand removal, and herbicides. Be vigilant about removing aggressive perennial weeds.
Prevent weeds before you plant:
Identify the weeds present.
Prepare the site and control existing weeds.
Dig out weeds or remove by hand. Follow up by irrigating and then removing the newly emerged weed seedlings.
Solarize the soil if possible.
If necessary, use herbicides for difficult to control weeds.
Consider drip irrigation.
Mulch is the key to a weed-free landscape:
Mulches prevent weed seed germination by obstructing sunlight.
Organic mulches are wood chips, bark chips and compost
Natural inorganic mulches are sand, gravel and pebbles.
Landscape fabrics are porous and long lasting.
Black plastic is not preferred.
When weeds invade your landscape:
Remove by hand when weeds are small and before they set seeds!
Hoeing easily removes young annual weeds.
Once the area is cleaned out, apply mulch.
When are herbicides necessary?
Use herbicides for special-problem situations before establishing new plantings or for difficult-to-control perennial weeds.
There are general herbicides that kill all plants and specific herbicides that kill only grasses and ones that kill only broadleaf plants.
Make sure you are using the correct herbicide at the correct application rate.
Herbicides can injure or kill desirable plants and should be used with great care.
■ For more gardening advice or topics from the Colusa County Master Gardeners, visit http://cecolusa.ucanr.edu