Common Conditions That Promote Certain Weeds

Webster defines weed as a plant that is out of place. In a corn field grass and clover are weeds; in a hay field volunteer corn or a small grain are weeds, in turf crabgrass and foxtail maybe the weeds. In most cases some type of a plant protection chemical is used to get rid of the weed. Sometimes this is only a temporary cure to improve the situation, after the effects of the treatment where off and the problem returns.

Dr. Sid Bosworth, University of Vermont, did some work and found that there are other factors that contribute to certain species of weed growth. Dr. Bosworth work is summarized in the following table.

Weed Conditions
Algae Excessive surface moisture
Annual Bluegrass Excessive surface moisture, compaction, mower too low, high nitrogen
Barnyardgrass Poor drainage
Birdsfoot Trefoil Droughty conditions, low nitrogen
Black Medic Droughty conditions, low nitrogen
Broadleaf Plantain High pH, compaction
Buttercups Poor drainage
Chickweeds Mower too low
Cinquefoil Species Droughty conditions, excessive surface moisture, low pH, general low fertility
Clover Species Low nitrogen
Coltsfoot Poor drainage, low pH
Common Chickweed Too shady
Common Mullein Low pH, general low fertility
Corn Chamomile Poor drainage, high pH
Corn Speedwell Compaction
Crabgrass Droughty conditions
Creeping Bentgrass Poor drainage, excessive surface moisture, mowed too low
Creeping Speedwell Too shady
Creeping Thyme High pH
Curl Dock Droughty conditions
Docks Poor drainage, low pH
English Daisy Low pH
Foxtail Species General low fertility
Goosegrass Droughty conditions, compaction
Hawkweeds Low pH, general low fertility
Henbit General low fertility
Hop Clover High pH
Knawel Low pH
Lady's Thumb Poor drainage, low pH
Leafy Spurge Doughty conditions
Mallow General low fertility
Moss Excessive soil moisture, mowed too low, too shady
Mouse-ear Chickweed Too shady
Nutsedge Poor drainage
Pigweed Droughty conditions
Pineapple Weed Compaction
Plantains Poor drainage, mowed too low
Prostrate Knotweed Compaction
Prostrate Spurge Droughty conditions, compaction
Rabbit Foot Clover Droughty conditions, low pH, high pH
Sheep or Red Sorrel Low pH
Speedwell Droughty conditions, mowed too low
Vetch Species Low nitrogen
Wild Carrot High pH, general low fertility
Wild Parsnip General low fertility
Wild Radish General low fertility
Wild Strawberry Low pH
Yarrow Droughty conditions
Yellow Woodsorrel Droughty conditions

Source: Bosworth, Sid. 1998. Using Plants as Indicators for Diagnosing Soil and Turf Problems. Turf Notes, Vol. 7, No. 2, p. 1-5. New England Extension Systems, Un. of Massachusetts Extension.

While there maybe other factors involved other than the ones listed, these are some general guidelines and conditions that can occur and be corrected relatively easily and inexpensively.

library/articles/common_conditions_that_promote_certain_weeds.txt · Last modified: 2010/03/10 16:14 by bill