ONE GARDENER TO ANOTHER: Tips on how to prune blackberry bushes
Published 6:45 am Monday, August 5, 2019
For the past few columns, we have been spotlighting vegetables. Vegetables are nutritious, delicious and easy to grow, and they can brighten up a boring meat-and-potato meal.
Most vegetables are annual plants if not started from seed, which means at the end of the season, they get composted to bring nutrients back to the soil for use by the crops to follow.
A few of my crops have reached that point. Although my peppers are still chock full, most of my other crops have petered out. This includes my blueberries and blackberries. But these plants are not annuals, so instead of plowing them under, a little pruning is in order.
This next series will be spotlighting fruits and berries since now is the time for many of them to be pruned and planted. This week, we are putting the spotlight on blackberries.
This year, we added a blackberry bush to our garden. Now that we (meaning me and the birds) have picked the bush clean, it’s time to prune it back. Pruning is always a tricky thing. Sometimes you cut a plant back to the ground, sometimes you just remove dead or damaged branches, and other times, you remove very select parts so the plant still produces flowers or fruits the next year. This is the case with blackberries.
The crown and root system of blackberries are perennial, meaning they will last for years, while the canes are biennial, meaning they last for two years. First-year canes are called primocanes. The second year, these canes are called floricanes.
The primocanes grow but do not produce fruit. After a dormant stage, in the second year, they are considered floricanes and will flower and set fruit. If you ever grew hydrangea, many varieties produce flowers on “old wood.” Blackberries and hydrangea will produce new foliage if cut to the ground. However, the buds that grow on the old wood will produce a flower, and in the case of the blackberry, subsequent fruit, would be lost.
After harvest, floricanes are removed. Primocanes are cut back when they have reached 3 to 4 feet in height, which will help force lateral shoot development. During the dormant season, cut lateral branches of primocanes back to 12 to 14 inches.
There are a couple of practices during planting that will ensure a healthy plant and plenty of blackberries. The two most important factors to consider in choosing a planting site are air and water drainage. Planting on sloping or level elevated sites will allow cold air to drain away on frosty nights. Lower lying sites or areas surrounded by trees could impede air drainage, which could cause damage from spring frosts at bloom time.
Plant blackberries in full sun and well-drained soil. Generally speaking, spaces that provide good air drainage also provide adequate water drainage. Although they tolerate a soil pH range of 4.5 to 7.5, an ideal soil pH is between 6.0 and 6.5.
Planting can be done in winter or early spring. Till the soil along the row. If using root pieces, place them horizontally in the soil, approximately 3 inches deep. Container-grown plants should be planted level with the ground. Place plants 3 to 4 feet apart for erect and semi-erect varieties and 6 to 10 feet apart for trailing varieties that require trellising. Rows should be spaced 10 to 12 feet apart.
Keep rows free of weeds and grasses as they will inhibit establishment and growth. Mulching around each plant will not only help suppress weeds but will aid in retaining soil moisture. Keep plants well-watered.
Blackberries are self-fertile, so a single variety can be used. They change color as they mature from green to red to maroon and finally to black. The shinier berries will be tart, but as they lose their sheen, they start to become sweet.
The official state fruit of Alabama, blackberries are delicious straight from the vine, baked into cobblers and pies or added to smoothies and salads. But blackberries aren’t just for sweet eats; they are making their way into savory dishes as well. The following recipe makes use of their perfect pairing with balsamic vinegar. Until next week, happy gardening and bon appétit!
Blackberry Balsamic Sauce
Delicious over grilled or roasted pork, venison, boar or elk
Ingredients
• 4 cups beef stock
• 1 cup blackberries
• 1 shallot, minced
• 1 clove garlic, minced
• 1 teaspoon green or pink peppercorns
• 1 tablespoon butter
• 1/2 cup balsamic vinegar
• 1/2 cup red wine, such as pinot noir
• 1 teaspoon honey
• 1 tablespoon fresh thyme
• 1 tablespoon cornstarch
• 1 tablespoon water or beef stock
Directions
In a saucepan, bring berries and stock to a boil; reduce heat and simmer until mixture is reduced to 3 cups, about 10 minutes.
In a medium skillet, add butter and sauté shallot, garlic and peppercorns until shallots are translucent, 3-4 minutes.
Stir in balsamic vinegar, wine, honey and thyme to skillet and bring to a boil, stirring occasionally. Simmer until reduced by half, 8-10 minutes.
Pour balsamic reduction into the saucepan with the berries and stock.
Using an immersion blender, blend ingredients until smooth. If you don’t own an immersion blender, transfer mixture to a blender. Be careful, mixture is hot!
Sauce can be strained through a sieve for a more polished presentation or served as-is for a more rustic appeal.
If the sauce is not thick enough, mix together cornstarch and water and add to the blackberry mixture. Bring to a quick boil to thicken. Keep warm until meat is ready. Enjoy.
— Irland, a member of the Limestone County Master Gardeners, can be reached at kippirland@hotmail.com. For more information on the Limestone County Master Gardeners, visit http://mg.aces.edu/limestone.