What Will Kill Acorn Sprouts?

Herbicide

• Herbicides made to kill broad-leaf weeds will kill acorn sprouts. Apply the herbicide according to the manufacturer's instructions for killing weeds. Broad-leaf herbicide can be used on lawns and will not kill the grass, making it a safe option for killing seedlings that have sprouted in the middle of a yard. The sooner the herbicide is applied to the sprouts the more effective it will be since larger seedlings can be more difficult to kill and may require a second application.

Mowing

• Acorn sprouts can be mowed down in order to kill them. Use a lawn mower if they are in a grassy area that is normally mowed. A weed trimmer works well for seedlings that are growing in areas that would not normally be mowed. Cut the seedling down as close to the ground as possible. The tip of the seedling releases hormones that help it to grow and develop. Removing the tip will keep it from growing. Removing enough of the leaves by cutting it down will prevent the seedling from converting sunlight into energy, and it will then die.

Destroy the Taproot

• Oak trees do not survive transplanting very well because they are especially sensitive to any damage to the taproot. Acorn sprouts also will not survive well if the taproot is damaged. Pull the acorn seedlings up by hand, removing as much of the taproot by possible, or use a shovel to dig just below the sprout and cut the taproot. For large groups of acorn sprouts, till the ground under to cut the taproots.

Cover

• Oak seedlings will not grow well in deep shade. Covering the seedlings so that they cannot receive adequate sunlight will kill them. Black landscaping plastic or landscaping fabric can be placed over the acorn sprouts. Keep in mind that this may also kill any other plants underneath the plastic or fabric. A layer of dirt or mulch placed over the sprouts will also kill them.