Best Fertilizer for Arborvitae

Arborvitae (Thuja species) are generally undemanding plants in terms of nutrition, but they respond visibly to targeted fertilizing when growing in poor soil, showing slow growth, or recovering from winter browning or pest damage. The right fertilizer applied at the right time supports dense, healthy foliage and helps the plant fill in gaps caused by browning or mechanical damage.

What Arborvitae Need

Arborvitae are moderate feeders that prefer a balanced nutrient supply with slightly elevated nitrogen to support the dense foliage production that makes them valuable as hedges and screens. A balanced or slightly nitrogen-forward ratio in the range of 10-8-6 to 14-7-7 suits most arborvitae in garden conditions.

Arborvitae grown as dense hedges in heavy clay or compacted soils benefit from fertilizing more than those in well-drained loamy soil with regular organic mulch. Yellowing foliage, particularly new growth that should be bright green but emerges pale, is a reliable indicator that fertilizing is needed.

Best Products

Miracle-Gro Tree & Shrub Plant Food Spikes (15-5-10)

A granular spike formulation convenient for application around arborvitae hedges. Drive spikes at the drip line per instructions, spacing them to cover the full planting. The 15-5-10 ratio provides adequate nitrogen for foliage density with potassium support for stress tolerance.

Espoma Holly-Tone (4-3-4)

Holly-Tone is formulated for acid-loving evergreens and suits arborvitae, which prefer a slightly acidic to neutral pH. The organic base feeds soil biology and improves soil structure over time. Slow-release granular; apply in spring and again in fall. Gentle enough to use annually without risk of over-fertilizing.

Jack’s Classic All Purpose Fertilizer 20-20-20 (water-soluble)

For arborvitae that need a faster response, a water-soluble balanced fertilizer applied as a soil drench delivers nutrients more quickly than granular slow-release products. Use at half the recommended rate to avoid excessive growth stimulation.

Dr. Earth Exotic Blend (5-4-6)

An organic granular formulation with a broad micronutrient profile and mycorrhizal inoculants that support root development. Particularly useful for newly planted arborvitae or those being established after transplanting.

Application Timing

Fertilize in early spring before new growth begins and optionally in early fall. Do not fertilize arborvitae after midsummer in cold climates: late-season nitrogen stimulates soft growth that is susceptible to frost damage. Apply granular products evenly under the canopy and water in thoroughly.

What Fertilizing Will Not Fix

Fertilizing does not reverse brown tips caused by winter desiccation, bagworm defoliation, or physical shearing damage. These problems require the damaged tissue to be pruned out and new growth to fill in. Fertilizing supports the new growth once the underlying problem is addressed. For trimming guidance that avoids creating the bare-wood browning patches common on over-sheared arborvitae, the how to trim arborvitae guide covers safe shaping technique in detail.