When to Plant Blueberries

The rule: plant dormant bushes

Blueberries are planted as two- or three-year-old nursery bushes, not seeds, so timing is about the plant’s growth cycle rather than soil temperature. A dormant bush has no leaves pulling water through its fine, shallow roots. If you plant it then, the roots can settle into the new soil before spring growth starts demanding water. A bush planted in full leaf in warm weather loses water faster than its disturbed roots can supply it. Blueberry roots lack root hairs, so they are especially slow to recover.

Bare-root plants have to go in while fully dormant, and the roots must stay moist from the moment you unwrap them. Potted plants allow more flexibility.

Cold-winter regions: early spring

Across the North and Midwest, plant as soon as the ground can be worked in early spring, before the buds swell. The University of Kentucky, Maine and New Hampshire extension services all give early spring before growth starts. Washington State University sets March to April for central Washington. That works out to roughly 4 to 6 weeks before your average last frost; the dates for your zone above show the window.

Early spring gives the roots cool, moist weeks to grow before summer heat.

Mild-winter regions: late fall or winter

Where winters are moderate or mild, planting can move earlier. Kentucky allows planting in late fall after the first frost, while bushes are dormant. Through the Deep South, winter is the standard season:

• Georgia: UGA says to get plants in time for winter transplanting.
• Florida: UF/IFAS recommends planting in winter, before spring growth begins. Spring growth there usually starts in late February or early March.
• California’s Central Valley: UC Cooperative Extension in Sacramento says most planting happens during dormancy, mainly in December and January, and in spring when nurseries are stocked.

In zones 9 and 10, plant from about December to February. Use only low-chill southern highbush cultivars (or rabbiteye in the cooler parts of zone 9, from about Ocala north in Florida), never northern highbush, which won’t get enough winter cold to crop.

Container plants outside the main season

UF notes that container-grown blueberries can go in at other times of year if you pay close attention to watering while they establish. UC Sacramento says potted plants can even be planted in summer. Hot-weather planting is still the riskiest choice. If you plant late, water often, mulch 4 to 6 inches deep at once, and expect slower growth the first year.

Start the soil months earlier

The date that matters most comes well before planting day. Blueberries need soil around pH 4.5 to 5.5, and elemental sulfur takes months to lower pH. Penn State notes it needs warm weather to work, so sulfur added in late winter does little before spring.

• Kentucky: till sulfur in at least 60 days before planting and retest 60 to 90 days after applying it.
• UGA: apply sulfur six months ahead.
• UC Sacramento: add it six months to a year before planting.
• Washington State: add sulfur the fall before, or as much as 12 months ahead, because surface applications after planting barely reach the roots.
• Penn State: test and amend in early fall for spring planting.

So for an April planting, test your soil the previous spring or summer and add sulfur by fall. If you’re short on time, plant in a raised bed or a large container filled with an acidic mix of peat and pine bark, rather than in native soil that is still too alkaline.

What happens after planting

Hold off on fertilizer at planting. Maine feeds three to four weeks after planting. UGA waits until new leaves emerge, which in Georgia is late March to early April. Remove the flowers in the first spring, and in the second spring too for highbush, so the bush builds roots and canes. Expect a small first crop two or three years after planting, and full crops around years four to six.