How to Grow Foster's Holly
Wikimedia Commons
Foster's Holly
Ilex crenata 'Convexa'
shrubFoster's Holly is a compact, evergreen shrub with small, convex leaves and a dense, rounded growth habit. It is a cultivar of Japanese Holly valued for its ornamental foliage and ability to tolerate shearing for topiary and hedging. This slow-growing plant produces small black berries and maintains its attractive appearance year-round.
When should you plant Foster's Holly in your zone?
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Example Foster's Holly timeline · Pittsburgh, PA (Zone 6b)
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Plant Foster's Holly
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Foster's Holly
Late summer into fallBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Foster's Holly dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-9, with best performance in zones 6-8
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Get my Foster's Holly timeline →Growth Stages
Establishment (Year 1)
3-6 monthsSmall transplant developing root system with minimal above-ground growth
Water regularly; apply 2-3 inches of mulch; avoid heavy pruning; protect from wind and extreme temperatures
Juvenile Growth (Years 1-2)
12-24 monthsSlow development of compact, dense foliage with convex leaves; plant gradually filling in prescribed space
Maintain consistent moisture; light shaping pruning to encourage branching; fertilize lightly in spring with acidifying fertilizer
Vegetative Maturation (Years 2-4)
24-36 monthsPlant achieving fuller, more defined shape with denser branching; characteristic convex foliage pattern well-established
Prune to shape as desired; can be sheared for hedging or topiary; continue regular watering; mulch maintenance
Flowering & Fruiting (Spring-Summer)
4-6 monthsSmall, inconspicuous white flowers in spring followed by development of small black berries on female plants
Plant male and female plants in proximity for berry set; deadhead if berry production not desired
Winter Dormancy
4-6 monthsEvergreen foliage retained; growth slows significantly; plant appears fully mature and ornamental
Reduce watering; protect from harsh winds and heavy snow; minimal pruning needed; plant remains attractive throughout season
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Remove affected leaves; spray with insecticidal oil or neem oil; improve plant vigor with proper watering
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Spray with horticultural oil in late winter; prune heavily infested branches; encourage natural predators
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Increase humidity; spray with water; use miticide if severe; avoid excessive fertilization with nitrogen
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Hand-pick infested foliage; prune affected branches; biological controls with Bt (Bacillus thuringiensis)
Uses
Topiary and Formal Hedging
OrnamentalFoster's Holly's dense, fine-textured foliage and slow growth make it ideal for creating precise topiary shapes and formal hedges. Its ability to tolerate repeated shearing while maintaining attractive appearance makes it a classic choice for formal gardens. [source]
Landscape Screening and Privacy
HouseholdThe evergreen foliage provides year-round screening and privacy barriers when planted in groups or rows. Its compact size makes it suitable for foundation plantings and small garden spaces. [source]
Wildlife Food Source
WildlifeFemale plants produce small black berries attractive to birds and other wildlife throughout fall and winter. The dense foliage provides shelter and nesting sites for small birds. [source]
Floral and Holiday Arrangements
CraftFoliage can be harvested year-round for fresh or dried floral arrangements and holiday decorations. The small leaves and berries add texture and interest to mixed arrangements. [source]
Harvest Tips
Not typically harvested; grown for ornamental purposes. Berries can be collected in fall for wildlife food or dried arrangements, but avoid consuming as they are mildly toxic to humans. Foliage can be cut for floral arrangements year-round.
Fun Facts
- 🌱 Foster's Holly (Ilex crenata 'Convexa') is a Japanese cultivar whose name comes from the distinctly convex (curved outward) shape of its small leaves, which are unusual among holly species
- 🌱 Despite being called a 'holly,' it produces much smaller berries than traditional American or English hollies, and the berries are less toxic to humans, though still best avoided
- 🌱 This cultivar is so slow-growing that a 30-year-old plant may only reach 3-4 feet tall, making it an excellent investment for long-term gardens and landscapes
Gardening Terms
New to gardening? Learn about terms used in this guide:
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