When Should I Spend Money to
Control Weeds?
Early in the growing season is the most important time to control weeds.
If crops are kept weed free for their Critical Weed-free period - beginning
with planting, emergence or budbreak - no yield reduction will occur.
Weeds that emerge after the critical period will not cause yield loss,
although they may cause other problems.
Critical Weed-free Period for Horticultural Crops
| Crop |
Critical Weed-free Period |
| Apples, new plantings |
During May and June |
| Apples, bearing |
Budbreak until 30 days after bloom |
| Beets |
First 2-4 weeks after emergence |
| Cabbage, early |
First 3 weeks after planting |
| Carrots |
First 3-6 weeks after emergence |
| Cucumbers, pickling |
First 4 weeks after seeding |
| Lettuce |
First 3 weeks after planting |
| Onions |
First the whole season |
| Potatoes |
First 4 weeks after planting |
| Squash |
Early plantings compete better |
| Strawberries, new |
During May and June |
| Tomatoes, fresh |
First 36 days after transplanting |
|
Tomatoes, seeded
|
First 9 weeks after seedling
|
Growers may still decide to control late-emerging weeds for efficiency
of harvest, improved quality or to reduce the weed seed bank. However,
remember that choosing a weed management program that keep weeds controlled
during these times will prevent yield loss.
