Blackberries – Gardening Tips from the Culinary View


as recommended by Michael Vidrine

When I was a boy my family would go “berry-ing”  this time of year.   Each armed with a bucket and a stick we would pick wild dewberries.  The bucket held the harvest and the stick was used to probe for unwanted critters amongst the thorny canes.  I’m sure this kind of harvesting still goes on in many places around the world since some kind of blackberry (genus Rhubus) is native to almost all the world’s continents. Nowadays I mostly harvest from my cultivated blackberry plantings – what my father always called “tame” blackberries.  The developed varieties of blackberries we grow now are selected cultivars which generally produce larger fruit on more upright canes than our native trailing dewberries. The crown and the roots of the blackberry are long-lived perennials however the above ground canes the plants produce are biennial – that is each cane only lives for 2 years.  First year canes – called primocanes – usually are only vegetative and produce no fruit.  The second year the canes become floricanes which flower, fruit and then die.  There are a few newer varieties of blackberries that have been developed to produce some fruit even on the primocanes and then again on the second year floricanes. Blackberry varieties can also be thorny or thornless.  Thorny varieties tend to produce more fruit than thornless but with the added inconvenience of having to deal with the thorns – which botanically are considered “prickles”  although they feel like thorns to me.  I’m a fan of the thornless varieties and am quite satisfied with their productivity.  Healthy blackberries can produce 5 pounds of fruit or more per plant. Blackberries are not too fussy about growing conditions but do best in full sun and in a well drained soil with a pH of 4.5 to 7.5.  Plants in higher pH soils may have trouble accessing iron and may exhibit chlorosis which can be improved by adding chelated iron either to the soil or sprayed on.  To keep the canes in bounds and make mowing and harvesting easier, blackberries are usually grown with some support .    Several simple blackberry support systems can be found on the internet.  We use a 4-wire system  – two wires on either side of the row of plants spaced 2 feet apart with the lowest wires at about 3 feet above the ground and the top two wires at about 5 feet.   Any supports should be fairly open to allow easy access for harvesting and spent cane removal. Blackberry plants, like most other perennial fruiting plants are usually planted in the late fall through very early spring  so the roots can get well established before the heat of summer.   They can be purchased either bare root or potted and are typically planted 3 feet apart in the row and at the same depth they were grown.   New plantings will need consistent watering to get established.  Mature plantings will need supplemental watering during the hotter months to ensure good cane growth and fruit production.  Mulching the blackberry planting helps to preserve moisture and reduce weed growth. In our garden, blackberries have very few pests or diseases compared to most other fruits we grow.  Occasionally I will have to knock down stinkbugs or in a wet season treat for fungal issues.  Wildlife – especially birds will help themselves to some of the fruit as well, but we usually have plenty to share.  Blackberries benefit from a mostly nitrogen fertilizer applied in the spring and again in midsummer – a couple of ounces per plant each time.  As they grow, new canes should be tucked in the support system and then tip pruned when they reach the top of the support to encourage additional branching and greater fruit production.  After the harvest is done, the old floricanes should be pruned at ground level and removed – they are done and will not fruit again.  Removing the old canes soon after harvest allows the new canes – next year’s fruit producers – more room and access to sunlight.  Note: spent cane removal as well as harvesting  is much more pleasant with thornless varieties and the primary reason that I grow them.  The Aggie Horticulture website has specific recommendations on several varieties that will do well in our area.  In our garden, the thornless variety Ouachita has done quite well. Blackberries do not continue to ripen once picked so they need to be picked ripe for best flavor and sweetness.  When fully ripe, blackberries turn from shiny black to a somewhat more matte black.  In the peak of the season, berries will need to be picked every couple of days.  Any berries that aren’t eaten in the garden can be stored in the refrigerator for 2 or 3 days.  Blackberries are fairly perishable and longer storage will generally require freezing or processing into juice, jelly, preserves or wine.  Blackberries are a good source of fiber, antioxidants and vitamins C, K and A but the primary reason to grow them is that they produce a lot of great tasting fruit.  Fresh berries eaten in the garden kind of define summer.  Blackberry cobbler from fresh or frozen berries are a yearlong southern favorite and blackberry juice makes a wonderful sorbet.  For a truly decadent desert try a blackberry chiffon pie.  Last but not least, blackberries are in the rose family and when in full bloom in the spring are just as attractive to me (and our bees) as any of our landscape rose plantings. Michael Vidrine Brazos Valley Gardener, Orchardist, Apiarist and Instructor

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