How to Grow Convex Leaf Holly
Wikimedia Commons
Convex Leaf Holly
Ilex crenata 'Convexa'
shrubConvex holly is a compact, dense evergreen shrub with small, glossy, distinctively convex (bulging) leaves that create a unique textured appearance. It produces small white flowers and bright red berries on female plants, making it attractive year-round. This dwarf variety is popular for hedging, topiary, and ornamental landscapes.
When should you plant Convex Leaf Holly in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Convex Leaf Holly timeline · Pittsburgh, PA (Zone 6b)
-
Plant Convex Leaf Holly
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
Harvest Convex Leaf Holly
Late summer into fallBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Convex Leaf Holly dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5b-9a, with best performance in zones 6-8
Sign up free to see if Convex Leaf Holly grows in your zone — and get a personalized planting timeline.
Get my Convex Leaf Holly timeline →Growth Stages
Establishment
6-12 monthsYoung transplant with minimal growth; root system developing underground
Keep soil consistently moist without waterlogging. Mulch around base with 2-3 inches of organic mulch. Water regularly until established (6-12 months). Protect from harsh winds.
Vegetative Growth
Year 2-3Shoots lengthen and foliage fills in; plant develops dense branching structure with characteristic convex leaves
Water regularly during dry periods. Begin light pruning to shape if desired. Apply balanced, slow-release fertilizer in early spring and early summer. Remove any diseased or damaged branches.
Mature Vegetative
Year 3 onwardsPlant reaches desired size with full, dense foliage canopy; compact mounded or pyramidal form well-established
Maintain regular pruning schedule to preserve shape and density. Water during droughts. Fertilize in early spring with holly-specific or low-nitrogen fertilizer. Mulch annually.
Flowering
4-6 weeks (spring)Small, inconspicuous white flowers appear in leaf axils; primarily on female plants (spring)
Do not fertilize heavily with nitrogen, as this reduces flowering. Maintain consistent moisture. Avoid pruning immediately before or during flowering if berry production is desired.
Fruiting & Winter Interest
Fall through winter (September-March)Female plants develop bright red berries that persist through fall and winter, providing ornamental and wildlife value
Do not remove berries during fall/winter harvest work. Ensure male plant (pollinator) is nearby for berry set. Berries persist longer if plant is in cooler climate or partial shade. Maintain plant health to support berry production.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
-
Spray foliage with water to dislodge; use neem oil or horticultural oil in early morning or late evening; ensure adequate humidity
-
Prune out heavily infested branches; apply horticultural oil in dormant season; spray with insecticidal soap during crawler stage
-
Improve air circulation with pruning; avoid overhead watering; remove infected leaves; apply fungicide if severe; ensure soil drains well
-
Spray with insecticidal soap or neem oil; use horticultural oil; prune out heavily infested shoots
-
Hand-pick in early morning; use pheromone traps away from plant; apply neem oil; apply beneficial nematodes to soil
Uses
Hedging & Topiary
OrnamentalConvex holly is excellent for formal hedges, borders, and intricate topiary shapes due to its dense growth and small leaves. Its compact habit makes it ideal for creating defined landscape structures and ornamental forms. [source]
Winter Interest & Berries
OrnamentalFemale plants produce bright red berries that persist through winter, providing striking color and food for wildlife when most other plants are dormant. Combines evergreen foliage with seasonal berry interest. [source]
Wildlife Food & Shelter
WildlifeThe dense evergreen foliage provides year-round shelter and nesting sites for birds and small animals, while berries offer winter food sources for birds such as robins, cedar waxwings, and mockingbirds. [source]
Cut Flower Arrangements
CraftBranches with berries are popular in fall and winter floral arrangements and holiday decorations. The glossy foliage and persistent berries add texture and color to mixed arrangements. [source]
Foundation & Border Plantings
HouseholdThe dwarf, compact growth habit makes convex holly ideal for foundation plantings, borders, and low hedges around homes and landscapes. Works well in small to medium-sized spaces. [source]
Harvest Tips
Berries are primarily ornamental and typically not harvested for culinary use. For floral arrangements, cut stems with berries in fall or early winter when berries are fully colored and firm. Cut at a 45-degree angle just above a leaf node. Use sharp pruning shears and harvest in early morning. Can be used fresh in arrangements for 2-3 weeks.
Fun Facts
- 🌱 The distinctive convex (bulging outward) leaves give this variety its name and are unusual among holly species; most hollies have flat or slightly concave leaves
- 🌱 Convex holly is dioecious, meaning male and female flowers grow on separate plants; only female plants produce berries, and a male pollinator must be nearby for berry set
- 🌱 In Japan, where this variety originated, it is called 'Hiiragimochi' and traditionally used in ornamental gardens and bonsai cultivation for centuries
Gardening Terms
New to gardening? Learn about terms used in this guide:
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Convex Leaf Holly planting timeline
Tell us your zip code and we'll calculate exactly when to start Convex Leaf Holly seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.
Get my Convex Leaf Holly timeline →