Fungus & Weed Control

Fungus Control

  • Choose plant varieties that are tolerant of or resistant to the fungi in our area.
  • Plant roses in full sun, at least 3 feet apart for good air circulation.
  • Avoid over watering.
  • Remove and carefully dispose of dead or diseased leaves and flowers. Do not add them to the compost pile.
  • To control powdery mildew on roses: spray both sides of rose leaves with: 2 tablespoons mild liquid soap, 2/3 teaspoons baking soda in 1 gallon water. Spray in the morning, weekly.
  • Spray leaves at the first sign of powdery mildew with an anti-transpirant (e.g. Wilt-Pruf or Cloud Cover) as a preventative (not registered as fungicide, but has been reported to be effective).
  • Or use sulfur-based fungicides, the least toxic of the conventional fungicides).

Weed Control

  • Pull weeds out with roots, or cut off weeds just below the surface with a hoe, minimizing soil disturbance (soil disturbance stimulates dormant weed seeds). Kill weeds before they begin to flower and produce seeds! To kill the roots and seeds of weeds and the insects in a selected area, cover area for 4 - 6 weeks. in the summer with clear plastic sheeting (1 millimeter thickness is fine), seal with soil at edges. Wet soil thoroughly before laying plastic. Remove plastic before planting. Clear plastic heats sub-surface soil better than black.
  • Cover areas of garden you want weed free with woven black garden fabric before you plant. You can spread bark over it and it won't disintegrate like black plastic. Garden fabric lets water drain through while preventing weeds from growing.
  • Cover bare areas of garden with 5 inches of mulch.
  • Or, cover bare areas with living ground cover like grass, vetch, annual rye grass, or crimson clover to crowd out weeds. Improves the soil also.
  • In lawns, sprinkle grass seed in bare areas after weeding to prevent weeds from returning.
  • Mow your grass to 2 inches, no shorter. Discourages weed growth. Mow weekly. Encourages dense growth of grass shoots. Crowds weeds. Use commercially available soap solution/weed killers.
  • Weeds can develop resistance to chemical herbicides (weed killers). If you use herbicides, limit use and paint or squirt product directly on individual weeds.
  • Give herbicides enough time to work. Don't over apply. Control runoff of herbicides. Do not apply weed killers if rain is forecast. Runoff goes directly into our creeks. Herbicides may be toxic to the wildlife in and around our creeks.


  • Soap-based moss killers are available. Some gardeners have been known to use bleach to kill moss in gardens. We do not recommend this practice. Yard runoff into the storm drain or creeks could be hazardous as bleach is very toxic to fish and other marine creatures.