PL. —Vaccinium corymbosumBotanical illustration — drop image
Vaccinium corymbosum

Highbush Blueberry

SpringSummerFall
4a7bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Highbush blueberry is one of the most rewarding shrubs for the home garden — small white bell flowers in spring feed early pollinators, berries ripen in succession from July through September depending on cultivar, and the fall foliage turns brilliant scarlet and orange. Plant two or more cultivars for cross-pollination and a longer harvest window.

In Zone 6b, early cultivars (Duke, Hannah's Choice, Patriot) ripen from late June into July; mid-season (Bluecrop, Blueray, Bluegold) through August; late season (Herbert, Liberty, Aurora) into September. Half-high hybrids (Chippewa, Polaris, Northcountry) are more compact and very cold-hardy. Soil pH is the single most important factor: blueberries will not thrive above pH 5.5 — test and amend with sulphur before planting.

Growing blueberries? Read the blueberry guide — acid soil, feeding, keeping the birds off, and which cultivars ripen when, timed to your frost dates.
Care guide
SunFull sun; at least 6 hours for best fruiting
WaterModerate; consistent moisture especially during fruit development; shallow-rooted
SoilAcidic (pH 4.5–5.5), well-drained, humus-rich; essential to acidify if pH is above 6
Spacing4–6 feet; plant two or more cultivars for cross-pollination
Height4–6 feet
Zone4a – 7b
Native RegionAL, AR, CT, DE, DC, FL, GA, IL, IN, KY, LA, ME, MD, MA, MI, MN, MS, NH, NJ, NY, NC, OH, PA, RI, SC, TN, VT, VA, WV, WI
Frost hardy
Seasonal tasks
spring
watchTest soil pH annually; top-dress with sulphur or acidified fertiliser if above 5.5
cutPrune in late winter: remove oldest canes (darker bark) to the ground, thin to 6–8 main canes
watchFlowers opening — ensure cross-pollination by planting two cultivars nearby
watchNet bushes before berries colour — birds will strip them within days of ripening
Common problems

Botrytis (grey mould)

Symptoms

Grey fuzzy mould on petals and stems, worst in cool wet conditions.

Treatment

Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.

Mummy Berry

Symptoms

New shoots and leaves wilt, blacken, and die in spring. Infected berries turn tan or pink, shrivel into hard 'mummies', and drop to the ground.

Treatment

Remove and destroy mummified berries and blighted shoots. Rake and dispose of fallen fruit and leaves. Apply 2 inches of fresh mulch in early spring to bury overwintering spores, and prune for airflow.

Blueberry Stem Blight

Symptoms

Sudden wilting and browning of leaves on individual canes, with reddish-brown discoloration in the wood beneath the bark. Affected canes die back, often spreading downward from a wound.

Treatment

Prune out infected canes 6–8 inches below visible discoloration and destroy them. Disinfect tools between cuts. Avoid wounding plants and keep them vigorous with proper water and acidic soil.

Pests

Spotted Wing Drosophila

Drosophila suzukii
Symptoms

Soft, collapsing berries with small puncture marks; white larvae inside ripening or ripe fruit.

Treatment

Harvest fruit promptly and frequently. Remove and dispose of overripe or fallen berries. Use fine-mesh netting or traps. Refrigerate harvested fruit immediately.

Japanese Beetle

Popillia japonica
Symptoms

Adults skeletonize leaves and devour petals and buds; aggregations escalate rapidly. Grubs destroy turf in late summer and fall.

Treatment

Hand-pick adults in early morning into soapy water — beetles are sluggish when cool. Neem oil applied to foliage deters feeding but must be reapplied after rain. For grubs, apply milky spore (Bacillus popilliae) to turf — it takes 1–3 seasons to establish but provides long-term biological control. Beneficial nematodes (Heterorhabditis bacteriophora) applied in late August when grubs are young and near the surface offer faster results. Never use pheromone traps.