Analyzing Weed Problems in Natural Areas and Restorations

Match your weed issues to the ecosystem triggering event. Then look for holistic permanent solutions to prevent their return. *Native Species

Species	Soil Disturbance	Clay Soils	Clonal Species	Nitrogen Enrichnment	Livestock Grazing	Early Succession	Road Salt	Allelopathy
Bittersweet, Oriental	X	X	X	X	X	Forest gaps	X	X
Black Locust	X			X	X		X	X
Bluegrass	X	X	X	X	X	X
Boxelder*	X	X				X
Brome Grass, Hungarian(Smooth)	X		X	X	X	X	Moderate
Buckthorns, Common & Glossy	X	X		X	X		X	X
Burdock	X			X
Cattails*	X			X			X
Celandine, European	X	X			X			X
Clover, Red & White	X	X		X	X
Creeping Bellflower	X		X	X	X
Creeping Charley	X		X	X		X
Crown Vetch	X	X	X	X
Curly Pondweed	X	X	X	X			X
Curled Dock/Sheep Sorrel	X			X	X	X
Dame’s Rocket	X			X
Dandelion	X	X			X
Eurasian Water Milfoil	X		X	X			X
Fescue	X	X	X		X		X
Foxtail	X		X	X		X
Garlic Mustard	X			X				X
Gray Dogwood*	X	X	X		X		X
Hawkweeds	X					X		X
Honeysuckles, Bush or Japanese	X	X	stems					X
Leafy Spurge			X		X			X
Lily-of-the-Valley	X		X		X
Mulberry, White & Hybrids	X	X				X	X	X
Mullein	X				X	X
Multiflora Rose	X	X	Stems		X
Olives, Russian/Autumn	X			X			X
Parsnip, Cow (Wild)	X	X			X		Moderate	Moderate
Phragmites (Common Reed)	X		X				X	X
Prickly Lettuce	X	X		X		X
Purple Loosetrife	X	X		X	X		X	A Little
Quack Grass	X	X	X	X	X		X
Queen Anne’s Lace	X					X
Ragweeds, Common & Giant*	X	X		X	X	X
Reed Canary Grass			X	X	X	X
Siberian Elm	X					X	X
Stinging Nettle	X			X	X
Sumacs, Smooth & Staghorn	X		X			X	X
Sweet Clovers (Yellow & White)	X	X		X			Moderate	X
Teasel	X	X			X
Thistles, Bull, Canada, Nodding/Musk	X X	X X	Canada	X X	X X	X X		X X
Timothy	X	X		X		X
Tree-of-Heaven	X		X			X	X	X
Watercress			X
White Poplar	X	X	X				X	?

Solutions: If your weed problems all basically follow a pattern on this chart you can make a management plan to neutralize those weed producing conditions.

1. Soil Disturbance: Annual & Biennial weeds & many non-natives need soil disturbance to thrive Prevent future disturbance. Enrich soil with organic matter. Add topsoil. Burn the site. Allow all leaf litter and dead plants to return their nutrients to the soil.

2. Clay Soils: This is a problem of construction, soil erosion, and any excavation. Prevent further disturbances. Allow leaves & dead stems to return organic matter to the soil. Add soil and/or mulch to increase organic matter.

3. Clonal Growth: You will need to follow specific herbicide instructions to remove them since

they spread by the root. Some of the worst weeds!

4. Nitrogen Enrichment: Some weeds enrich the soil with nutrients and select against native

species. Limit fertilizer use. Restrict runoff with settling basins. Burn the site to remove

nitrogen in leaf litter. Add wood mulch , sawdust, corn starch, sugar, or wheat gluten.

Bacteria will use up nitrogen as those materials decompose.

5. Livestock Grazing: Weeds are frequently resistant to grazing & they gain a competitive advantage over tasty natives. Prevent future grazing or keep it to a minimum. Plant conservative species. Burn the site to promote conservative species.

6. Early Succession: These species can be beaten by promoting more climax or conservative species. .Promote site stability & add conservative species to push succession along. Burning the site will help promote climax species at the expense of weedy annuals & biennials. Remove all seed heads.

7. Road Salt: Sodium can burn many native species & give tolerant weeds a competitive advantage. Screen site with a salt tolerant hedge, settling basins can collect salt, spread gypsum (calcium sulfate) to neutralize road salt,