TOP HAT Blueberry

Overview & origin

‘Top Hat’ is a dwarf blueberry from a cross between highbush blueberry (Vaccinium corymbosum) and lowbush blueberry (Vaccinium angustifolium).

It belongs to the compact hybrid blueberry group, often marketed as half-high or dwarf varieties.

Developed in the United States 🇺🇸 through breeding work for blueberries suited to small spaces and containers.

Especially appreciated for a naturally rounded habit, small size, and both ornamental and fruiting value.

Main characteristics

Strengths & advantages

• Miniature size → Ideal for small gardens, balconies, patios and limited spaces.

• Naturally rounded habit → Very compact shrub that keeps an attractive shape with little pruning.

• Container growing → Excellent for pots and urban gardens.

• Ornamental interest → Abundant white spring flowers and beautiful red fall colour.

• Edible fruit → Flavourful small blueberries with mild wild-blueberry-like flavour.

• Good hardiness → Several nurseries rate it zone 3, making it appealing for Quebec gardens.

• Versatility → Can be used as either a fruiting or ornamental shrub.

• Relatively easy care → Small size simplifies harvesting, pruning and maintenance.

Limitations & points to consider

• Limited production → ‘Top Hat’ is better known for ornamental appeal than fruit yield. Do not expect harvests comparable to large commercial varieties.

• Small fruit → Berries are generally small, sometimes barely larger than a pea.

• Cross-pollination → Although it can fruit alone, another compatible cultivar may improve fruit quantity and size.

• Acidic soil required → Excessive pH can cause nutrient deficiencies and slow growth.

• Drought sensitivity → Shallow roots need consistent moisture, especially in pots.

• Container growing → Roots are more exposed to winter freezing in pots.

• Slow to moderate growth → Allow time for establishment and structural development.

• Variable classification → Sources do not always agree on exact botanical classification: marketed as either a dwarf highbush blueberry or a highbush–lowbush hybrid.

Recommended growing practices

Here are some tips for success with ‘Top Hat’:

Location:

• Choose full sun, ideally at least 6 hours of direct sunlight.

• Light partial shade is tolerated, especially where summers are very hot.

• Excellent for patios, balconies and small gardens.

Soil:

• Maintain pH between 4.5 and 5.5.

• Use an acidic, light growing medium rich in organic matter.

• Add sphagnum peat moss or composted pine bark.

• Ensure excellent drainage while retaining good moisture.

• Avoid calcareous soil.

Spacing:

• Allow about 60 to 90 cm between plants in the ground.

• For pots, choose at least 30 to 40 litres to encourage root development.

• Provide adequate drainage holes.

Care:

• Keep the growing medium moist without waterlogging.

• Apply pine bark mulch to retain moisture.

• Use fertilizer formulated for acid-loving plants in spring.

• Remove dead, weak or damaged branches.

• Avoid severe pruning to retain its compact habit.

• Gradually renew old branches when necessary.

Winter protection:

• In the ground, hardiness generally allows it to survive Quebec winters without special protection.

• In pots, protect the container from severe cold.

• Place pots in a sheltered location or insulate with protective material.

• Do not let the growing medium dry out completely in winter.

Pollination:

• Can produce fruit without another cultivar nearby.

• For better fruiting, plant another compatible blueberry nearby.

• ‘Northblue’ and ‘Northcountry’ may be considered, but flowering compatibility with ‘Top Hat’ must be verified locally.

• Encourage bees and bumblebees.