When to Plant After Using Roundup Weed Killer

Roundup (glyphosate) Weed Killer

How long do I have to wait to plant after spraying weeds with Roundup? -Ron

According to Scotts, the manufacturer of Roundup (glyphosate) weed killer, its safe to plant ornamental flowers, shrubs, and trees the next day; and they say you can plant grasses and edible plants and trees after three days.

As weed killers go, glyphosate is considered relatively safe, because of how quickly it breaks down. However, when using a glyphosate weed killer such as Roundup, I’d always give it a few days to do its job and be gone before you start digging. Here’s why:

  • Needs Time To Work: Contact weed killers, such as glyphosate, are absorbed through the leaves and slowly make their way down to the plant roots. If you plow, dig, or disturb the weeds before they’re good and dead, you risk breaking off some live roots that will sprout again.
  • Residues in Edible Plants: If applied properly and carefully, the small amount of residue on your soil surface shouldn’t harm new plants. However, you wouldn’t want those residues to be absorbed by plants you plan to eat, so I’d hold off on planting herbs and vegetables for several days.
  • Might Harm Seed: New, tender sprouts from seed might also be vulnerable to soil residues, so give them a chance to break down before sowing grass or other seeds.

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