How can I keep weeds out of my asparagus patch?
Weed control, especially of grasses, can be a problem in asparagus production. Asparagus is a poor competitor with weeds. Weed control can be accomplished by:
• very shallow hand hoeing,
• application of labeled pre-emergence herbicides in early spring about three weeks before spear emergence,
• applying glyphosate (non-selective herbicide) to control perennial weeds, such as Canada thistle, quack grass, and field bindweed early in the spring before the spears emerge and after the last harvest,
• applying a 4-inch-thick layer of organic mulches such as wood chips, straw, or compost after harvest.
An old gardener's tale is to apply rock salt to the asparagus patch to keep grass seedlings from germinating. We do not recommend the use of salt as a weed killer. Salt will not harm the asparagus, but it creates a crust that damages soil structure and inhibits water penetration in the soil.