How to Fertilize Holly Bushes
Holly is not a heavy feeder, but the right fertilizer at the right time keeps foliage deep green and supports flowering and fruit. The key is an acid-forming feed applied in spring, not a heavy hand.
When to feed holly
Feed holly in early spring, just as new growth begins, and if needed again in early summer. Stop feeding by midsummer: fertilizer applied late in the season pushes soft new growth that will not harden before winter and is easily damaged by cold. Established hollies in decent soil often need little more than a spring application.
What to use
Hollies are acid-loving plants, so a fertilizer formulated for hollies, azaleas, and evergreens — one that is acid-forming and includes iron — suits them best. Organic options such as compost, composted manure, cottonseed meal, and an acidic mulch of pine bark or pine straw feed the soil gently while helping keep the pH low.
Yellow leaves and pH
Yellowing leaves with green veins (chlorosis) are usually a sign the soil is too alkaline, which locks up the iron holly needs. The lasting fix is to lower soil pH with elemental sulfur or an acidifying fertilizer rather than simply adding more nitrogen. A soil test tells you where you stand before you amend.