Foster Holly Tree

Ilex x attenuata 'Fosteri'

The Foster Holly Tree is a classic, highly adaptable broadleaf evergreen tree prized for its elegant pyramidal structure, fine-textured glossy foliage, and spectacular autumn-to-winter berry display. Developed as a natural hybrid, this slender beauty brings timeless structure and vibrant year-round color to residential landscapes and commercial properties alike.

In spring, subtle clusters of small white flowers emerge among its softly spined, dark green leaves. By mid-to-late autumn, these blooms yield an abundance of dense, bright red berries that persist throughout the winter months. Contrast against the rich evergreen canopy makes it a standout architectural feature during drab winter seasons while offering a bustling haven for local birds.

The Ecological Footprint

• Wildlife Sanctuary: Offers dense, spiny evergreen cover that provides safe nesting sites and vital winter shelter for songbirds and beneficial garden fauna.

• Winter Bird Buffet: Generates thick clusters of persistent red drupes that serve as a crucial late-season food source for overwintering birds.

• Pollinator Support: Spring blossoms attract native bees and small beneficial pollinators looking for early nectar sources.

• Property Buffer: Dense growth habit functions efficiently as a biological windbreak, noise reducer, and visual privacy screen year-round.

The Honest Harvest (What to Expect)

• The Perks: Highly self-fertile (produces heavy berry crops without needing a male pollinator), features softer foliage than traditional American Holly, holds a tight natural pyramidal form with little to no pruning, and boasts excellent heat and drought tolerance once established.

• The Caveats: Performs poorly in alkaline or poorly drained soils; severe iron chlorosis (yellowing leaves) can occur if soil pH is too high. Leaves have soft spines that require handling with gardening gloves during planting or trimming.

Specifications

• Botanical Name: Ilex x attenuata 'Fosteri' (Ilex x attenuata 'Foster No. 2')

• Common Names: Foster Holly, Foster's No. 2 Holly, Hybrid Holly

• Mature Height: 20-30 feet

• Mature Width: 10-15 feet

• Growth Rate: Moderate (12-24 inches per year)

• Lifespan: 50+ years

• USDA Zones: 6-9

• Chill Hours: *

• Sun Preference: Full sun to partial shade (best berry production and foliage density in full sun)

• Soil Type: Moist, well-drained, acidic loams or sandy soils; tolerates clay if well-drained

• Soil pH: Acidic (4.5-6.5)

• Water Needs: Moderate; requires regular watering during establishment, drought tolerant once mature

• Flower Color: Small, dull white; spring

• Fruit Type: Bright red, long-lasting berries (drupes); autumn through winter

• Pollinators: Native bees, honeybees

• Growth Habit: Dense, compact, narrowly pyramidal evergreen tree

• Spacing: 6-8 feet apart for a dense screen; 12-15 feet apart for specimen planting

• Landscape Uses: Specimen focal point, evergreen privacy screen, corner foundation planting, informal hedge, accent tree

• Maintenance Level: Low

Planting & Care Guide

• Hydration: Thoroughly saturate the root ball prior to planting, and water deeply 1-2 times per week during its first full growing season to encourage deep root establishment.

• Siting: Select a full sun to partial shade location with well-draining, acidic soil. Ensure adequate spacing away from tall structures to allow its natural pyramidal form to expand.

• Mulching: Apply a 3-inch layer of organic mulch (such as pine bark or pine needles) around the base to regulate soil temperature, retain moisture, and naturally preserve soil acidity. Keep mulch a few inches away from the trunk.

• Establishment: Provide consistent moisture during prolonged dry spells over the first two years. Once established, it demonstrates strong tolerance to short droughts.

• Pruning: Naturally maintains a tight, symmetric shape requiring minimal pruning. If hedging or shaping is desired, prune in late winter or early spring before new growth appears.

• Fertilization: Feed in early spring with an acid-forming, slow-release fertilizer formulated for evergreens and hollies, especially if planted in marginal or slightly alkaline soils.