Most of us can bend over and pull weeds (and we recommend it!) but that's usually a temporary solution. It's critical to know a weed's lifecycle to know the best strategy to get rid of them long term.

• Annuals: Reproduce only by seed; Complete their life cycle in less than 12 months and are Subdivided into summer annuals and winter annuals. Annuals tend to be easily controlled with ample mulch.
  
  • Winter Annuals: Germinate in the fall and produce a small seedling, which goes dormant to survive the winter (broadleaf seedling is called a winter annual rosette). They resume their growth in early spring and complete their life and die before the end of the growing season
  • Summer Annuals: Germinate in the spring, grow and produce mature seed before freeze up
• Biennials-Reproduce only by seed. They complete their life cycle in less than 24 months. Seeds usually germinate in spring or summer and the seedlings develop into low growing rosettes (these rosettes can become quite large). Rosettes go dormant in the fall and resume growth early the following spring and will set seed before the end of the fall
• Perennials- Live for more than two years. They produce seed each year. Many species capable of reproducing both by seed and vegetatively. Some especially tough perennial weeds will have no problems pushing up through 5 cm of mulch.

Once your space is weed-free, a generous layer of mulch will help keep it that way!

Survival and spread of weed species depends on:

• Seed production

• Spread of seeds

• Survival and germination

• Spread and growth of vegetative reproductive structures

Seed Production

• Weedy plants can produce copious amounts of seed

      Adapted from PL SC 25 Weed Control

A viable seed that fails to germinate when all conditions are favourable for germination is said to be dormant

• Dormancy mechanisms can be either
  • Exogenous (physical) – hard seed coats
  • Endogenous (internal) – internal temperature changes

Adapted from Integrated Weed Management; British Columbia Ministry of Agriculture and Lands

Seeds move throughout the landscape in may ways, including:

• Wind – dandelion produces small seeds with specialized structures known as a pappus; foxtail barley has light fluffy awns; Russian thistle and kochia break off at the soil surface and roll – often called “tumbleweeds”
• Water – seeds float on water – leafy spurge, scentless chamomile
• Animals – seeds are eaten and pass unharmed through an animal’s digestive system; seeds of burdock, cocklebur, bluebur and cleavers attach to animal fur and clothing
• Humans – few weeds that are serious problems in western Canada are actually native to North America; most of our problem weeds originated in the home areas of the early European and Asian settlers; toadflax, tansy, scentless chamomile and purple loosestrife were introduced as ornamentals

Aside from seeds, weeds spread through the following ways:

• Creeping roots – capable of sending up new shoots and establishing new plants (Canada thistle and perennial sow-thistle)
• Rhizomes – specialized underground stems that can put down roots and send up shoots to produce a new plant (quack grass)
• Stolons – specialized above-ground stems that grow horizontally along the ground and establish new plants (ground-ivy)
• Bulbs – specialized stems and leaves that can produce a new plant (wild garlic)
• Tubers – specialized underground stems that store large amounts of food and can produce new plants (Jerusalem artichoke)