Saturday, April 2, 2016

Grow Big Blueberries in Grants Pass

Bimart blueberry collection

         We have a LOT of blueberry plants in local stores this year: three-year-olds in #2 pots at Bimart and Sandy’s Nursery.  Sandy’s has Northern plants; Bimart has both Northern varieties and couple of Southerns: Legacy, with taller, arching, growth; and Sunshine Blue, a compact dwarf 2 to 3 feet tall.

Southern and Northern blueberries at Bimart.  Note the old leaves on the Southern.

Northern blueberries have thicker, stiffer stems by their third year, and are deciduous; their leaves turn bright red in the fall and then fall off.  Southern Rabbiteye blueberries seem to take our hot summers better.  They have thinner, more arching growth, and smaller leaves that turn colors sometimes but are semi-evergreen, holding some or all of their leaves through the winter in Grants Pass. 

South and North together in my garden.  The old leaves on the Southern bush didn't get cold enough to turn color.  Both plants were transplanted a few years ago; the Southern is several years older.

Unlike many shrubs, blueberries benefit from growing in pots for the first few years; bigger plants grow better.  For a few years, I was buying #1 pots at Bimart in the spring and repotting to #2s for planting in the fall and saying so.  Bimart seems to have responded.

Legacy, 3rd year after planting in light, rich soil

          Blueberries don’t like to be planted into plain soil, unless it is exceedingly light and rich, like potting soil.  Otherwise, rather than planting them in the ground, it is better to set the plant on top of the ground and surround it with compost as deep as its root mass. 

Sunshine Blue dwarf Southern Rabbiteye in March.  This plant is about 5 years old, hard life, moved several times and roots confined by gravel and creeping Jenny ground cover to less than a square yard.

Young blueberries grow a sponge of roots only 4-6 inches deep in their pots, putting down a deep taproot only after 4-5 years.  Unlike most other shrubs and perennials, blueberries roots will sink into the soil as the compost is worked in by worms; most other potted plants will sit on top of the soil as the compost is worked in, and be left high and dry.
          Cover that compost with coarse mulch like ¾” nugget bark, walk-on fir bark, or pine needles, to keep it from drying out and keep the roots cool and moist.  2 inches of leaves in the fall are probably the best mulch to maintain organic matter in the soil.  It is vital to not let the soil be exposed to sun.  Bark protects and insulates soil when the leaves have been pulled into it by worms.
Southern Oregon has hot, dry summers, not the best conditions for growing blueberries, which like their heads in the sun and their roots cool and moist, but don’t like a lot of heat or dryness at any time.  Indeed, most garden plants prefer a little less heat and a lot more humidity than we have in Grants Pass. 

A standing mister. These put out a finer mist than emitters bought to attach to irrigation line.

          The key to getting fast growth and big berries on young plants in our area is keeping a mister running nearby through the heat of our summer days.  It does not cause fungal infections, and helps many plants grow over a wide area of the garden.  24/7 misting works well where the mist can spread out and dissipate.
An incident shows how vital misting is here.  A customer turned off one mister for a week near an isolated plant that had been producing big, tasty berries.  The remaining berries all stopped growing and immediately ripened, producing little berries that were not juicy and flavorful.      
                               
Revised March 2016, online at GardenGrantsPass.blogspot.com.  Like Garden Grants Pass on Facebook.
Gardening is easy if you do it naturally.  Litter is tagging, marking the territory of the disorderly.
Rycke Brown, Natural Gardener          541-955-9040        rycke@gardener.com