Is there an organic weedkiller for lawns?

Asked October 18, 2015, 5:30 PM EDT

A friend has a lawn that is full of weeds - clover, dandelion and others I can't identify. I've offered to spray them with Weed-B-Gone, but she is afraid of the toxins getting into her fruit trees, which are planted throughout the lawn. Is there an organic selective weedkiller available that will kill the weeds but not the lawn? If not, is there an organic weedkiller I could mix up myself?

Clark County Washington lawns and turf organic herbicides for lawns

1 Response

There are two types of herbicides used in lawns. Pre-emergents prevent weed seeds from germinating, but are not effective on established weeds.
Post-emergents kill existing weeds. Here are some organic options for controlling turf weeds. See this WSU article for more details.

Post-emergent herbicides kill established weeds already present in your garden. Here are examples of organic post-emergent herbicides:
citric acid-- Damage is limited to the area of tissue contact
Perfectly Natural Weed & Grass Killer Organic Herbicide

ammoniated salts of fatty acids--Contact herbicide, will not move through soil.
woodstream.com
Concern Fast-Acting Weed Killer
Garden Safe Brand Weed & Grass Killer

potassium salts of fatty acids-- Damage is limited to the area of tissue contact
Safer Fast Acting Weed & Grass Killer Organic Herbicide

d-Limonene (citrus oil)--Damage is limited to the area of tissue contact
Lilly Miller Worry Free Weed & Grass Killer
Nature’s Advenger


Pre-emergent herbicides control weeds by preventing any seeds from germinating. Care must be taken not to plant your vegetable seeds when the pre-emergent is still active, usually 4-6 weeks.

Corn Gluten --An organic pre-emergent. It inhibits root growth of susceptible germinating seeds. It is not effective on established perennial weeds.
Examples:
Bradfield Organics Luscious Lawn Granulated
Corn Gluten, Concern Weed Prevention Plus
Down to Earth Corn Weed Blocker,
Concern Weed Prevention Plus,
St Gabriel PreMerge,
Preen Vegetable Garden Weed Preventer