Weed Science

Why is Weed Control Important?

Controlling weeds is critical to the success of any crop and grapes are no exception.  Weed control is extremely critical in the establishment and subsequent years until vines have reached a mature size capable of producing a full grape crop.  Research has shown that in order to maximize growth in newly planted vineyards weeds must be controlled from the time the vines are planted through July.  The same is true for the second and third years after planting.  The faster a vine grows after planting the sooner the vineyard can become productive thus recouping establishment costs and hopefully retuning a profit. 

In established vineyards weeds can reduce crop yield, created habitats favorable for vertebrate pests, interfere with grape root borer management, and reduce worker efficiency.  Weed control is important from an aesthetic perspective for vineyards that are highly visited due to a winery, tasting room, or some other venue located on the property.

Picture 1. Weed-free herbicide strip in an established vineyard.

The predominant weed management technique in vineyards is to utilize a sod/weed-free strip system.  A three foot wide (1/5 ft on each of side of the vine) strip in the vine row is maintained weed free while the row or drive middle is established in a perennial grass (fescue) sod (Picture 1).  The perennial grass row middle prevents soil erosion and allows for equipment movement through the vineyard during periods of wet weather. 

How Do I Maintain a Weed-free Strip?

The most economical and effective way to maintain a weed-free strip in a vineyard utilizes the miracles of chemistry through the development of herbicides.  There are a number of very effective herbicides that control emerged weeds and that prevent weeds from emerging at all. Using the appropriately calibrated equipment, herbicides can be applied safely without adversely affecting the vines or the environment. 

Herbicide programs are most effective when preemergence (prevent weed seedlings from emerging) are used in combination with a non-selective postemergence herbicide (glyphosate, glufosinate, or paraquat).  Good herbicide stewardship requires using herbicides with multiple modes of action and rotating herbicide programs so the same combination of herbicides are not used year after year.  For a complete list of recommended herbicides and timings go to  www.smallfruits.org/ipm-production-guides/

Picture 2. Newly planted vines protected with a grow tube.

One critical need when using herbicides in newly planted orchards is vine protection.  Grow tubes are a requirement in newly planted vineyards to prevent direct herbicide contact with the immature bark on juvenile vines (Picture 2).

If I Want to Grow Grapes Organically How Do I Control Weeds?

Options for “organic” herbicides are very limited and are really not very effective.  Growers not desiring to use conventional herbicides will have to depend on organic mulches, which will require some weed removal, and/or mechanical removal.  There are several companies that make specialty tillage equipment to work around vines.  Another non-conventional herbicide means of controlling weeds utilizes flaming, however this must be done carefully to avoid trunk damage and prevent fires especially during periods of dry weather.  Landscape fabrics that are a barrier to weeds are an option as well.

Download a list of files here: