What cultural methods can be used to control weeds in the vegetable garden?

Question: 

What cultural methods can be used to control weeds in the vegetable garden?

Answer: 

There are several cultural or management techniques the gardener can use to reduce weeds in the vegetable garden. 

Watering Directly

Water plants directly by hand or using soaker hoses or drip irrigation systems.  Unlike overhead watering with a sprinkler, this provides water directly to the plant and does not provide the moisture needed for weed seeds to germinate.

Tilling Prior to Planting

Tilling can help uproot and destroy existing weeds, but it also brings buried and dormant seed to the surface where they are exposed to the sunlight and warm temperatures they need to germinate.  Till the vegetable garden two to four weeks prior to planting.  This purposefully brings weed seeds to the surface and forces them to germinate early.  Right before planting, hoe or lightly cultivate again to kill the newly emerged weeds.  This technique of weed control is referred to as the stale seed bed technique.  Utilize a mulch so the soil does not have to be disturbed again that growing season to prevent new weeds from germinating. 

Planting Cover Crops

Cover crops also help to reduce weed issues.  These fast growing crops are grown to cover the soil when not otherwise planted and can outcompete weeds for nutrients, sunlight, moisture, and space.  Cover crops are particularly useful for weed control over the winter months, before planting late-spring or summer vegetables, after vegetable harvest in the fall, or in-between wide-spaced rows.  These crops cover the soil preventing germination of weed seeds and when terminated, provide a mulch that further reduces the germination of unwanted plants.

Additionally, some cover crops have allelopathic properties and produce various substances while they are growing that can prevent the germination or growth of other plants.  Cover crops that may work well for home vegetable gardens include,

  • Winter rye
  • Winter wheat
  • Buckwheat
  • Rapeseed
  • Annual ryegrass
  • Field peas
  • Oats
  • Oilseed radish
  • Sweet clover.

It is important to grow and terminate cover crops effectively to see their benefits.  When not grown properly, cover crops can become difficult weeds themselves.  More information about growing cover crops can be found in the following publications: HORT 3026 – Cover Crops in Vegetable Production SystemsHORT 3041 – Short Duration Cover Crops for Vegetable Production Systems

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