Weeds' Patient & Prolific Progeny – Know Thine Enemy

The information below is sobering to keep in mind when dancing with weeds and letting them go to seed.  Some of those seeds will be viable long after we have become part of the earth in which they germinate!

Bindweed flowering

WEED SEEDS PRODUCED per PLANT 

and NUMBER of YEARS VIABLE

Many of these are in our Garden Plots

Bindweed 40 yrs   Long-lived perennial with deep root system – never let it seed!

Curly dock Rumex crispus  29,500   70 yrs

Foxtail   20 yrs

Canada Thistle   21 yrs

Crabgrass  8,000

Dandelions  100-200 seeds/head  6 yrs  Germinates immediately after reaching maturity...it has no after-ripening requirements. Seed keeps in a ziplock bag in a refrigerator for 2 years with extremely high germination.

Evening Primrose  70 yrs

Galinsoga ciliata   7,500    10 yrs + in soil

Lambsquarters Chenopodum album  72,450    7% viable after 38 yrs

Mullein Verbascum thapsus   223,200,   70 yrs

Nutsedge  100 – 2,000 

Pigweed (redroot)  117,400   10-40 yrs

Plantain Plantago major  36,000  40 yrs

Purslane Portulaca oleracea  52,300    40 yrs

Redroot pigweed Amaranthus spp  117,400   3 yrs Unknown viability after 38 yrs

Shepherd's purse Capselia bursa-pastoris 38,500   16 yrs

Smartweed  19,300

Ragweed (Common)  3,380   39 yrs

HOW to GROW WEEDS:

• Seed germination occurs at or very near the soil surface. 
• Light increases germination. 
• The seed germinates when soil is moist and soil temperature is at least 50°F; however, germination is more rapid when the soil temperatures are closer to 77°F. 
• Germination occurs throughout the growing season.