Sucker Stopper is a ready-to-use plant growth regulator containing naphthaleneacetate (NAA) that prevents unwanted sucker and sprout growth on trees, applied directly to trunk suckers, root suckers, pruning cuts, and lateral limbs to stop new shoots from forming without repeated manual pruning.

What Is a Sucker on a Tree?

A sucker is an unwanted, vigorous shoot that grows from a tree's roots, trunk base, or interior branches rather than from its desired framework, often appearing after a pruning cut or root disturbance and detracting from the tree's overall form.

How Does Sucker Stopper Prevent New Sprouts From Growing?

A plant growth regulator prevents new sprouts by interrupting the signal that triggers shoot development at the treated site, rather than removing existing growth the way pruning does.

Naphthaleneacetate is the active ingredient behind that effect; Sucker Stopper applies it directly as a ready-to-use spray, eliminating the need to mix a concentrate before treating a tree.

Where and When Should Sucker Stopper Be Applied?

Sucker Stopper is applied during the growing season or summer pruning season, once new sprouts reach 6 to 12 inches in height, directly from its spray bottle. It addresses three common trouble spots:

• Directly onto trunk, basal, and root suckers as they emerge.
• Several inches around a pruning cut to stop sprouting from the wound.
• Along lateral or upright limbs where unwanted shoots are forming.

What Trees and Plants Is Sucker Stopper Labelled For?

Sucker Stopper's label covers a specific group of fruiting and ornamental trees rather than all woody plants generally:

• Apples
• Pears
• Citrus
• Olive
• Redwood
• Woody ornamental plants

Is There an Alternative to Sucker Stopper for Controlling Tree Suckers?

A brush-on application is available for growers who prefer that method over spraying; Sucker Punch RTU is a Bonide-brand alternative labelled for apples, olives, pears, non-bearing citrus, and ornamental woody plants, applied with either the brush built into its cap or as a spray. Its label excludes bearing citrus trees and states the product cannot be shipped to Canada.

Frequently Asked Questions

Does Sucker Stopper replace the need for pruning?

Sucker Stopper reduces the need for repeated manual pruning by preventing new sprouts from forming at treated sites, though it works alongside rather than in place of general pruning practices for shaping a tree.

Can Sucker Stopper be used on bearing citrus trees?

Sucker Stopper's label lists citrus among its covered plants without distinguishing bearing from non-bearing trees, which differs from Sucker Punch RTU, whose label specifically excludes bearing citrus; the individual product label should be checked before treating a bearing citrus tree.

How soon after a sucker appears should Sucker Stopper be applied?

Sucker Stopper is applied once new sprouts reach 6 to 12 inches in height, during the growing season or summer pruning season.

Is there a shipping restriction on either product?

Sucker Punch RTU's label states it cannot be shipped to Canada; no such restriction appears on Sucker Stopper's product page.