Photos Help With Weed Identification

The 10 most unwanted weeds include crabgrass, pigweed, ragweed and Canada thistle. 

May/June 2013

By Kris Wetherbee 

Annual weeds are prolific seed producers. These seeds will germinate, grow and complete their life cycle in one growing season. Perennial weeds multiply by seed, by bulbs, by underground stems called rhizomes, or by way of stolons, which are creeping horizontal stems that form roots and new plants all along their length.

Weed Identification  Weed Variety  Annual or Perennial  Control Advice 
Crabgrass 

Crabgrass
(Digitaria spp.)

Annual

Best control is through cultivation. Pull entire plant, including roots.
Redroot Pigweed 

 Redroot Pigweed (Amaranthus retroflexus)

Annual

Till beds to encourage seeds to germinate, and then hoe seedlings under and mulch deeply. Hoe out young plants, or use an alternative herbicide containing acetic acid or clove oil. Dig or pull older plants.
Common Ragweed 

 Common Ragweed (Ambrosia artemisiifolia)

Annual

Hoe seedlings, and hand pull or mow larger plants before they set seed.
Lambs Quarter 

 Lamb’s Quarters (Chenopodium album)

Annual

Easy to hand pull; gets out of hand if allowed to seed. Hoe or pull plants as they appear.
Purslane 

 Common Purslane
(Portulaca oleracea)

Annual

Hoe seedlings, and then mulch heavily. Pull larger plants by hand or shovel. Control with a flame weeder or use an alternative herbicide. Easily sprouts from root or plant pieces left on the soil.
Prickly Lettuce 

Prickly Lettuce
(Lactuca serriola)

Annual/
Biennial

Hoe seedlings and young plants; pull plants or use a mechanical weeder. Remove plant below the rosette of leaves, then mulch heavily; wear sturdy gloves.

Field Bindweed 

Field Bindweed (Convolvulus arvensis)

Perennial

Tough weed to control; torch young shoots with a weed flamer. Pull seedlings immediately; carefully dig out older plant and roots. Mulch larger areas with black plastic for at least a year. Bindweed can spread up to 30 feet, so be on the lookout for new sprouts and seedlings.
 

Curly Dock
(Rumex crispus)

Perennial

Pull seedlings by hand; use a shovel to take out larger plants, being careful to remove as much of the taproot as possible. Any pieces of taproot remaining can resprout.
Canada Thistle 

Canada Thistle
(Cirsium arvense)

Perennial

Its deep root system requires continual attention to control. Repeatedly cut down shoots or dig out plants; remove all roots. Repeat every month as necessary, and wear sturdy gloves.
Common yellow Wood Sorrel 

Common Yellow Wood Sorrel (Oxalis stricta)

Perennial

Hoe seedlings, pull plants and mulch heavily. Do not let this go to seed. Thwart this acid lover with an alkaline soil amendment such as wood ash to bring the soil pH closer to neutral. 


Read more:
Learn how to use a variety of techniques to combat weeds in Natural Weed Control.

 

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