How Safe Is It to Spray Roundup Around Plants?

Susceptible Plants

• Glyphosate, an active ingredient in Roundup, can damage most herbaceous and woody plants. Vegetable plants, including pepper and tomato, are also susceptible. Apply Roundup only to weeds and undesirable plants.

Damage

• Roundup kills weeds by moving through plant tissues and into the roots where it restricts the production of several amino acids that plants need to grow. Even if you are not attempting to spray your desirable plants, it can easily happen. If even a small amount of Roundup touches the roots or leaves of your plants, it can harm them. Roundup injury commonly occurs when applied in high winds and droplets drift onto desirable plants. Spatter may also occur when you apply Roundup too quickly or at high pressure.

Symptoms

• It can be hard to tell right away if you've damaged plants by spraying Roundup because it can take up to two weeks for symptoms to appear. Symptoms include yellowing, diminished growth of young leaves, and the death of young, actively growing plants. On woody plants, damage may be undetectable until the next spring when expected leaves and buds do not emerge or appear damaged. (

Preventing Damage

• The best way to prevent Roundup damage is to avoid spraying near desirable plants. This can obviously cause problems for weed control, so if you must use Roundup, take precautions. Place a cardboard box over the weed in question and spray into the box to prevent drift. If you are using an adjustable applicator, put it on a setting that creates large drops as opposed to misting. If you use a pump sprayer, only use it at half pressure, keeping the nozzle close to weeds during application. Avoid applying on windy days.

Prognosis

• Whether a plant survives accidental Roundup exposure depends on the amount of herbicide that contacted the plant, the plant's health at the time of contact and growing conditions after exposure. If only a small amount of Roundup touched the plant, it will likely survive, but if a plant absorbed a lot, it may die or become more prone to pests and diseases. The time of year is also a factor. Plants injured in fall will likely sustain less damage because growth is slowed during this time of year. If a plant is damaged, the best recourse is to water and fertilize the plant as usual to improve its strength. Avoid eating vegetables damaged by Roundup.