What Blackberries Are Invasive: How To Control Blackberry Plants

By: Jackie Carroll

Cultivated species of blackberry are well-behaved plants that need only a little pruning to keep them manageable, but invasive species are a terrible menace that can be very difficult to control. They form impenetrable thickets that overrun more desirable native plants and block access by livestock, wildlife, and humans. Invasive blackberries are very difficult to eradicate. Even a small piece of stem or rhizome left in the soil can result in a new plant and, over time, a new thicket.

What Blackberries are Invasive?

Of all the species of blackberry (Rubus), cutleaf blackberry (R. laciniatus) and Himalaya blackberry (R. discolor) are the most destructive. Fortunately, these invasive blackberry plants are easy to distinguish from other blackberries. While most blackberries have round stems, cutleaf and Himalayan blackberries have ridged stems with five angles. The leaves of Himalayan and cutleaf blackberries have five leaflets where most other types have only three leaflets.

Weedy blackberries spread underground and take root wherever the long, arching vines touch the ground. Animals eat the berries and spread the seeds to distant locations through their digestive tract. One seedling can eventually form a massive thicket.

How to Control Blackberry Plants

The first step in controlling invasive blackberries is to cut down the canes to a point just above the ground. Next, you can either dig up and dispose of the rhizomes or spot treat the tips of the canes with herbicide. Most of us would like to take the organic approach, but digging up a large thicket can be overwhelming. After digging out what you can, rototill the area several times during the season to make you have destroyed any bits of rhizome and crown left in the ground.

If you decide to use herbicides, apply the chemicals directly to the cut parts of the canes. Read the herbicide label completely, and mix and apply the product as instructed. Avoid using herbicides near plants that wildlife might eat. Store any remaining herbicide in the original container, or dispose of it according to the label instructions.

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Read more about Blackberries

Raspberries and Blackberries (brambles)

Brambles Planting and Maintenance:

Brambles are defined as any species belonging to the Rubus genus. This covers a large number of plants found growing wild in the woods and fields surrounding us. Brambles of interest to the home gardener, however, are domestic raspberries (red, black, yellow, and purple types) and blackberries (thornless and thorny types). Wineberry , Rubus phoenicolasius , should not be grown in the home garden. It escapes cultivation and is now recognized as an invasive, non-native pest harmful to the natural environment.

Bramble species vary by fruit color, growth habit (thus cultural practice), pest problems, and other characteristics. Bramble crowns and roots are perennial. Canes are biennial. The canes, typical biennial life-cycle is as follows: Each spring, canes known as primocanes emerge, grow tall, put out lateral branches, and overwinter. In the second growing year, the canes, now called floricanes, produce flowers and fruit. Floricanes die after fruiting and must be removed eventually. Usually, this is done in late winter before new canes begin coming up.

Bramble Types

Soil And Best Location

Thornless blackberry plants require rich, moist, soil and full sun exposure to thrive. Thornless blackberries prefer slightly acidic soil with a pH ranging from 6.5 to 7. Plant new plants in early fall or early spring in well-drained soil that contains no less than 2 percent humus or organic material. Thornless blackberries prefer sandy loams amended with coarse sands or clays. As vigorous growers, thornless blackberries need a good amount of space, so space plants about 5 feet apart. They are not deeply rooted plants, so cover new plants with only about 4 inches of soil.

Blackberry Weeds & Cobbler

When weeds are wonderful! Blackberry is an invasive, fast-growing & hard to eradicate garden pest plant — except when it is offering up a lot of tasty fruit in summer!

Fortunately, picking loads of summer-ripe berries is a delicious preemptive weeding method. Each berry we keep out of the mouths of birds (that poop plantable seeds) or keep from falling directly to the earth (where they sprout anew) is a win. Plus, we get an abundant harvest of yummy berries. Don’t miss one of our favorite recipes below!

Other ways we’re keeping these voracious blackberry weeds at bay right now:

A small view of our wall of blackberry weeds — aka “the briar patch”

Taking a machete to green shoots traveling overhead and along the ground. If we don’t whack these fast growing shoots back, they will root into the earth soon and help the weeds cover more ground.

We’re also cutting out the berry clusters that only have hard, pithy fruit still attached. Once the best berries are picked and summer weather dries out, the remaining clusters on older fruiting stems will ripen, but they’ll never be very tasty. Yet, they will have the capacity to form new plants.

Pick your fruit daily so none goes to waste or falls the ground to seed itself.

Staying on top of pulling volunteers wherever they appear on our property is also key. If you have fruiting blackberries, birds will poop seeds for you, thereby planting more brambles everywhere. Don’t ignore them! Young shoots are easy to pull you may not even need gloves against those tiny prickles and roots.

These summer efforts won’t eradicate our briar patch, but we really don’t want to completely eradicate them. We like the fruit, and the wildlife that lives in this area does too — from the bees that pollinate the flowers to the birds, deer, bunnies and other unknown critters that call this area home. Come winter, we will go hard on the vines with our machetes, but just enough to keep this invasive plant in check.

What to do with your preemptive weeding berry harvest:

Blackberry margaritas are a delicious way to reward yourself for preemptive bramble weeding (while you’re waiting for your cobbler to bake!)

We’ve made blackberry sauce, blackberry chicken, blackberry margaritas, blackberry mint juleps and several reduced sugar blackberry cobblers. And, since we’re hauling in about three to six pounds of berries everyday, we’re freezing them by the gallon to make blackberry jelly come autumn. Right now, it’s the cobbler we love the most!

Blackberry cobbler made with summer-ripe fruit topped with a lump-bumpy, rich crust sweetened with a touch of coconut sugar, which gives the crust a deep brown color. Yum!

Although I endeavor to do a lot of no-sugar, no-grain baking, I’m a fool for a traditional blackberry cobbler — made with wheat flour, butter and a bit of sugar. That being said, I hate a fruit dessert so over-sugared that the natural flavor of the fruit itself is lost. So, I’ve refined my recipe to call for about a cup and half less sugar than most cobbler recipes often suggest is necessary. And, as is traditional with cobblers, there’s no need to roll out the crust like you would for a pie. Easy-peasy!

Let me know what you think after you make one of your own.

Preemptive Weeding Blackberry Cobbler Print

  • 4-6 cups fresh blackberries, rinsed & picked over for bugs & prickles
  • 1/4 teaspoon ground cinnamon
  • 3/4 cup flour, sifted
  • 1/4 cup coconut sugar (or regular granulated sugar)
  • dash of sea salt
  • 6 tablespoons melted & cooled unsalted butter

Preheat oven to 350F. Place baking rack in middle of oven. Place another rack below it, and put a lined cookie sheet on the lower rack to catch any bubbling over messes.

Fill a deep 8-9″ pie dish about 3/4 of the way full with berries. Sprinkle with cinnamon and toss very gently. Set aside.

Place sifted flour, sugar and salt in a large bowl. Whisk together with a fork. Pour in butter and blend quickly. It will be very buttery and slightly crumbly. Don’t overwork it or you may have a tough crust.

Scoop tablespoon sized clumps of dough into your palm and flatten slightly. Place each clump into an overlapping layer to cover the berries. If you have some extra dough, crumble it over the top. Don’t expect a pie-perfect look! The cobbled-together look is what gives cobbler it name.

Place filled pie plate onto the middle rack of the oven & be sure the cookie sheet is positioned below it to catch anything that bubbles over.

Bake 40-50 minutes or until berries are bubbly and the crust is a golden brown.

Remove from oven and allow to cool for at least 15-30 minutes so the liquids gel a bit and to keep your mouth from getting burned. (Since I don’t call for a thickener, expect lots of succulent juice.)

Serve warm or cold with a dollop of vanilla ice cream.

Selecting and Caring for Blackberry Plants

By Cindy King, CPH, The Mill

Blackberry Plants are available only at The Mill of Kingstown

Blackberry plants can provide a delicious harvest of fruit for us and wildlife from July through September.

Each plant The Mill carries is labeled with name and we carry many varieties including-

  • Prime Ark 45 - late
  • Prime Ark Freedom – thorn less – early-mid
  • Chester – latest

Early and Late indicate fruiting times

  • Early- very late July into August.
  • Late – August into early Sept.

Plant in well-draining soil with lots of organics. Space 3-4 feet apart and trellis on wire or wood for support. Keep weeds out of garden as they compete for nutrition. Water if necessary at ground level.

Fruit is produced on 2-year canes. Once planted let canes grow for 2 years.

In the third early spring cut canes to 3-4 feet and lateral branches to 12 inches leaving 5-6 buds on each one. This is how you would continue to prune your Blackberries. At any time, you can remove damaged canes.

Fertilize yearly in early spring with a broadcast of 10-10-10 around each plant.

Blackberries can get wilt so never plant them near any plants that have been affected. If you develop wilt destroy the plant.

Washington State

Family: Rosaceae

Other Scientific Names:

Rubus armeniacus, Rubus discolor, Rubus procerus

Other Common Names: Himalaya blackberry
Weed class: C
Year Listed: 2009
Native to: Asia
Is this Weed Toxic?:

Why Is It a Noxious Weed?

It is a notorious invasive species in many countries around the world and costs millions of dollars for both control and in estimated impacts. This species spreads aggressively and has severe negative impacts to native plants, wildlife and livestock.

How would I identify it?

General Description

It is a rambling evergreen, perennial, woody shrub with stout stems that possess stiff, hooked prickles. It may grow up to 13.1 feet. Plants grow into impenetrable thickets.

Flower Description

Flower clusters (panicles) are flat-topped and have 5 to 20 flowers. Each flower has 5 petals that are white to rose colored and about 1 inch in diameter.

Leaf description

Leaves are alternately arranged on stems. Each leaf is palmately compound and made up of 3 to 5 (typically 5) leaflets with toothed margins

Stem description

Stems, commonly called canes, can reach up to 20 to 40 feet and can root at their tips when they touch the ground. Canes have hooked, sharp prickles, also called thorns, with thick bases. Stems green to reddish to purplish-red, strongly angled, and woody. They made dense thickets that are impassable and sprawl over the surrounding vegetation.

Fruit Seed Description

Flowers form blackberries—a grouping of small, shiny, black druplets that each contain one seed. Blackberries are about 1/2 inch to 7/8 inch in size.

Where does it grow?

It can grow in mixed and deciduous forests and a variety of disturbed sites such as roadsides, railroad tracks, logged lands, field margins and riparian areas. It does well in a wide range of soil pH and textures. Please click here to see a county level distribution map of Himalayan blackberry in Washington.

How Does it Reproduce?

It can reproduce by seeds and also vegetatively. Flowers can produce seeds with and without fertilization. It can vegetatively reproduce by re-sprouting rootstalks, rooting stem tips and root and stem fragments.

How Do I Control It?

Make sure to wear thick gloves and protective clothing when controlling blackberry to try to avoid, or at least minimize, injury from the thorns.

Manual/Mechanical Control

For a few plants or small infestations, plant stems can be cut back, leaving about a foot of stem (to not lose track of the plant), and then carefully pull back cut stems with a rake or other tool to allow room for digging up the roots. Example. Then, using a shovel or a tool with a long handle like a mattock or 3-prong tiller mattock, dig out the roots, making sure to remove the main root ball and as much of the spreading side roots as possible. Example of small root mass here. Roots that break off and remain in the soil may resprout, so make sure to monitor the area and control for resprouts and seedlings. Remove from site and dispose of stems and roots.

Cultural Control

Plants can be burned back to the ground, after obtaining any needed permission and permits, and then follow up with other control methods such herbicide on the resprouts as fire will not kill the roots.

Biological Control

Success has been noted from grazing, especially by goats, yet sheep, cattle and horses may also be effective. This method seems to control the population from spreading and becoming larger but does not eradicate the plants from the site.

Herbicide Control

There are a number of herbicide treatment options for Himalayan blackberry. Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

For More Information

See our Written Findings for more information about Himalayan blackberry (Rubus armeniacus).

Spring is the time to turn attention to blackberries and raspberries

CORVALLIS, Ore. – No matter how muddy the spring, it’s time to slip on your boots and gloves and take care of blackberries and raspberries.

Established red raspberries, including Meeker, Cascade Delight and Vintage black raspberries such as Jewel and blackberries like Marion, Boysen, Columbia Star, Navaho, and Triple Crown, need some care in early spring in order to stay healthy and productive.

These caneberries should be fertilized starting in early spring when new growth begins, said Bernadine Strik, berry crops professor with the Oregon State University Extension Service.

For raspberries, apply 1 ounce of actual nitrogen (N) per plant. For blackberries, apply 2 ounces. Split the total amount of nitrogen into thirds, applying the first in early April, the second portion in late May, and the last portion in mid- to late June.

To calculate the amount of fertilizer to use, divide the recommended amount of actual nitrogen needed by the percent nitrogen in the product, which is shown as the first number on the front of the bag. For example, in raspberries if you are using a granular fertilizer such as 16-16-16 (16 percent nitrogen), then you would divide 2 by .16 to get 6.25 ounces of fertilizer. So, you’ll need to use about 6 ounces of product (2 ounces of fertilizer per application) double this for blackberries.

“It’s best to spread the fertilizer evenly around the plant over the surface of the soil in the row,” Strik said. “I suggest an area about 2½ to 3 feet wide by 3 feet long for raspberries. For blackberries go 5 feet long.”

Keep the area where berries are growing free of weeds by removing them by hand. You can use a layer of sawdust or bark mulch to help reduce germination of weed seeds. Don’t apply more than about 2 inches deep.

In all these caneberries, the plants are perennial with long-lived roots and crowns (base of plant), but the canes are biennial. They are called primocanes in their first year of growth. Then after they overwinter, they become floricanes. They flower, fruit and then die.

Foliage on the new primocanes should be a healthy green color. A pale green or yellow color may indicate nitrogen deficiency, Strik said. If the plants seem to lack vigor, apply a little more nitrogen fertilizer.

Pruning caneberries can be confusing because different categories of raspberries and blackberries have separate pruning requirements. Strik lays it out like this:

Erect and semi-erect blackberries (as well as black raspberries), need summer and winter pruning to improve yield and fruit size. Erect blackberries form stiff, upright branches that don’t need much trellising. Semi-erect cultivars are vigorous and need sturdy supports. They should be pruned during the growing season so that they form lateral branches. Cut the new primocanes to about 3 feet high in black raspberries and erect blackberries and 5 feet in semi-erect blackberries. Now is the time to prune those lateral branches to 18 to 24 inches long for black raspberries and erect blackberries or up to 4 feet long for semi-erect varieties.

For trailing blackberries, the new primocanes should not be pruned in summer. After harvest, floricanes die and should be cut to the ground and removed from the trellis in late August. The new primocanes should be trellised in August or late winter after severe cold temperatures have passed. Wrap these around a two-wire trellis.

Summer-bearing red or yellow raspberries do not need to be pruned in summer. Take out the dead floricanes after fruiting in late summer. From January through early March, when plants are dormant, remove all the weak, broken and diseased primocanes to crown or soil level. If your plants are grown in a hedgerow, narrow the row to about 6 to 12 inches wide. You can shorten canes to about 5½- to 6-feet tall to make training and picking easier. Tie these canes to the trellis wires.

Everbearing (or primocane-fruiting) red and yellow raspberries will produce fruit at the tips of the new primocanes in late summer through fall and can produce an early summer crop on the base of the floricanes. In winter, to prune for two crops a year, remove all of the primocane tips that fruited last year. The base of these canes will fruit in June or July, when they are floricanes, which should be removed when they die after harvest in July. The late-summer/fall crop will be produced on the new primocanes that grow next season. Keep the hedgerow of primocane-fruiting raspberries to about 12 inches wide during the growing season.

To prune everbearing raspberries to produce in late summer to early fall, cut all canes to ground level in late February or early March when plants are dormant. When the new canes emerge, keep the row width to 12 inches apart.

This spring is a good time to look for new, improved varieties and established favorites in your local nursery or mail-order catalog. Most nurseries will order plants if they don’t carry the one you want. Strik recommends:

  • Trailing blackberries: New thornless Columbia Star and old favorites Marion and Boysen.
  • Erect, late-season thornless blackberries: Navaho
  • Semi-erect, last-season blackberries: Triple Crown.
  • Summer-bearing red raspberries: new Cascade Delight and Chemainus.
  • Yellow raspberries: new Cascade Gold and older favorite Meeker.
  • Everbearing (also called primocane-fruiting) raspberries: Vintage is a new red Anne is the best yellow.
  • Black raspberries: Jewel

Watch the video: Σμέουρο,το κόκκινο βατόμουρο και η καλλιέργεια του - Φυτώρια Ulterfita

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