Grow Big Blueberries in Grants Pass

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

Our local stores and nurseries stock two kinds of blueberries.  Northern blueberries have large leaves, thick, stiff stems, and are deciduous; their leaves turn bright red in the fall and then fall off.  Southern Rabbiteye blueberries have thinner, more arching growth, and smaller leaves that turn various colors in winter but are semi-evergreen, holding most of their leaves through the winter in this area.  

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.

They don’t like to be planted into plain soil, unless it is exceedingly light and rich, like potting soil. Indeed, they grow remarkably well in potting soil in wide, large pots.  Otherwise, rather than planting them in plain dirt, it is better to set the plant on top of the ground and surround it with enough compost to surround and cover the roots, if your plant is in a #1 (6”) or smaller pot.  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.  Six inches of compost makes rich, light soil after worms work it in..

Unlike most other shrubs and perennials, blueberries at this size will sink into the soil as the compost is worked in by worms; most other 6” potted plants will sit on top of the soil as the compost is worked in and are left high and dry.  If your plant is in a larger pot, dig a shallow dish hole, break up the soil below and around the hole, and then surround it with a level area of compost to just cover its roots.  Having level compost is vital; a rounded mound will shed water and be dry. Blueberries love their water.

Cover that compost with coarse mulch like ¾” nugget bark, walk-on fir bark, or pine needles or straw, to keep it from drying out and keep the roots cool and moist.  An evergreen ground cover like creeping jenny or clover can keep them cool as the mulch disappears.  Two inches of soft leaves in the fall are probably the best mulch to maintain organic matter in the soil, but I like to scatter our copious coffee and tea grounds into the mulch or ground cover after the leaves are eaten.  It is vital to not let the compost be exposed to sun; they like their roots cool.  Bark protects soil when the leaves have been eaten by worms.

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

          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.  Most garden plants prefer a little less heat and a lot more humidity than we have in Grants Pass. 

            Fast growth and big berries on young plants can be achieved by keeping misters running nearby through the heat of the summer days.  Leaving them on at night spreads moisture a lot farther.  Misters help many plants grow over a wide area of the garden.  Misting with well water can mineralize the soil, reducing acidity; humic acid or worm castings can counter that.  

An incident shows how vital misting is here.  A customer forgot to turn on one mister for a week near an isolated plant that had just started producing big, tasty berries.  The remaining berries all stopped growing and immediately ripened, producing little berries that were not juicy or flavorful.

                               

Revised August 2023, 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