Thinning Locust Tree: Deadwood Removal and Fertilization

Your 15-year-old honeylocust (likely 'Sunburst' or 'Shademaster') with dead limbs and sparse canopy needs cleaning pruning and vigor restoration.

Pruning

• Now: Remove only clearly dead limbs (brittle, no green under bark).
• Best time (Sept–Oct): Full structural pruning—remove crossing, rubbing, weak branches. Honeylocust bleeds less in fall.
• Do not top—ruins natural form and invites decay.

Fertilization

• Apply 20-10-10 or similar at 2–4 lbs per inch trunk diameter.
• Broadcast under canopy, water in well.
• Best in early spring or fall.

Water & Mulch

• 1 inch water/week during drought.
• Mulch ring to drip line (keep off trunk).

Watch For

• Mimosa webworm (webbing, skeletonized leaves)—treat with Bt or spinosad if seen.
• Cankers (sunken, dead bark)—prune out.
• Girdling roots—check base for circling roots.

Cleaning deadwood now and fertilizing will stimulate new growth. Full pruning in fall shapes the canopy.