Bronze, orange, or tan leaves that show up over winter usually come from cold, drying wind and winter sun, while yellowing during the growing season more often points to a nutrient shortage, wet roots, or pests such as leafminers and mites. When the color appears, and on which side of the shrub, narrows the cause.

Why does boxwood foliage change color under stress?

Because its small evergreen leaves stay exposed all year. In winter they keep losing moisture to wind and sun while frozen roots cannot replace it, and in summer the same leaves show nutrient, water, or insect problems as yellowing.

How can bronzing and yellowing be told apart?

By timing and pattern:

• Bronze, orange, or tan leaves on the exposed side after winter: winter windburn
• Even, pale yellowing of older leaves with slow growth: a nutrient shortage
• Yellow leaves with small blister like swellings: leafminers
• Fine pale speckling across the leaves: mites
• Yellowing and wilting in soggy soil: struggling roots

How is winter bronzing prevented?

With a deep watering before the ground freezes and a protective coating on the leaves. Ahead of cold, drying winter winds, the foliage is coated with Wilt Pruf Plant Protector Ready to Use Spray, which reduces moisture loss for three or four months as the film slowly wears away.

How is yellowing from a nutrient shortage corrected?

With slow, steady feeding rather than a burst of nitrogen. Where older leaves pale on a slow growing shrub, TreeHelp Premium Fertilizer: Boxwood fed in spring releases nitrogen gradually, avoiding the weak new growth that quick release nitrogen can push.

Frequently Asked Questions

Is boxwood bronzing a disease?

Usually not. Winter bronzing is a stress response to cold, wind, and sun, while disease more often shows as spots, dieback, or decline that keeps spreading.

Why is only one side of the boxwood bronze?

Because that side takes the most wind and winter sun. Shrubs on exposed corners or south and west facing sides tend to show it first.

Does bronzed boxwood turn green again?

Often, once growth resumes in spring. Leaves only lightly bronzed may regain color, while badly burned tips are trimmed after new growth appears.

How are leafminers controlled on a boxwood?

With a systemic soil drench. Leafminers appear on the pest list of Once A Year Insecticidal Drench with Merit, which is mixed and poured at the base of the shrub and protects for 12 months.

How are mites controlled on a boxwood?

With a contact insecticidal soap. Diluted at 1 part concentrate to 50 parts water, Safer Brand Insect Killing Soap is sprayed at the first signs of mites and repeated while they remain.