How to Prune Brambles & Grapes

How to Prune Brambles & Grapes

Pruning is one of the most important steps in keeping raspberries, blackberries and grapes healthy, productive, and beautiful year after year. Done correctly, it encourages strong new growth, improves air circulation, prevents disease, and ensures better fruit. Each plant has its own unique needs— raspberries and blackberries need thinning to boost berry production, and grapes require careful training for abundant harvests. Learning when and how to prune these plants will not only make your garden more attractive but also maximize the quality and yield of your fruit.

Raspberries Red & Yellow

Controlling Suckers:

  • Allow only the suckers that start close to the original plant to grow.

  • Remove any unwanted suckers that appear too far from the mother plant.

One-Crop (Summer-Bearing) Raspberries:

  • These raspberries produce fruit on two-year-old canes.

  • After harvest, the two-year-old canes die and should be removed.

  • The one-year-old canes that remain can be thinned in the fall or following spring:

    • Remove weaker canes.
    • Keep the healthiest ones and cut them back to 4–6 feet.
    • Leave about 5–10 canes per square foot of growing area.

Two-Crop (Everbearing) Raspberries

  • Everbearing raspberries fruit in the fall on one-year-old canes and again in the summer on two-year-old canes.
  • After the fall harvest, remove the top portion of the cane that fruited, leaving the rest for next year’s crop.
  • As with summer-bearing varieties, two-year-old canes die after harvest and should be removed in late fall or early spring.

Alternative method:

  • Some gardeners cut all canes to the ground each fall.

    • This eliminates the spring crop but results in a larger fall harvest and less pruning work.

    • Be aware: this method carries a risk of reduced yield if an early fall frost occurs.

    • Choosing an early-ripening variety can help reduce that risk.

Supporting Red Raspberries:

  • Red raspberries can be supported with tall stakes or a two-wire trellis:

    • Place the top wires about one foot below the pruned cane height.
    • Secure the wires on each side of the posts with staples or nails.
    • Crosspieces can be used to space the wires 12–15 inches apart.
    • A second set of wires can be added lower for extra support.
  • Tie canes to the top wires for stability.
  • Some varieties, especially everbearing raspberries, may not need support at all.

Black Raspberries

  • Spring Pinching
    When new one-year-old canes reach 18–24 inches tall, pinch back the tips by 3–4 inches. This simple step encourages strong fruiting laterals for next year’s berry crop.

  • After Pinching
    Once canes have been pinched, they can be left alone until late winter or early spring, when it’s time for pruning again.

  • Winter or Early Spring Pruning
    During the dormant season:

    • Remove all two-year-old canes that fruited the previous summer.
    • Shorten lateral branches (formed after pinching) to about 12 inches.
    • Thin out weak or damaged canes to keep plants healthy and productive.

  • Training and Shape
    Black raspberries grow best using the hill system. They usually stay close to their original planting spot and do not spread much. Properly pruned plants develop a rounded, globe-like shape, with fruit forming on the outer edges of the bush for easy picking.

  • Staking
    Staking can help support new plants during their first season, but after that, most mature black raspberry bushes will stand well on their own.

Blackberries

Growth Habit

Most blackberry varieties grown in Southeastern Idaho have a semi-erect growth pattern. Their pruning needs are similar to those of black raspberries.

Pruning Summer-Bearing Varieties

Summer-bearing blackberries require two main pruning sessions — one in late winter or early spring, and one during summer.

Pruning Everbearing Varieties

For everbearing types, pinch back the top growth once canes reach 24–36 inches to promote additional fruiting in the fall. Then, in late winter or early spring, cut all canes back to the ground to make room for vigorous new growth.

  • Dormant Pruning (Late Winter/Early Spring)

    • Remove all canes that produced fruit the previous summer.

    • Shorten any lateral branches to 2–3 feet long to strengthen the plant and improve fruiting.

  • Summer Pruning

    • When new canes reach 24–36 inches tall, pinch off the top 1–2 inches of growth.

    • This encourages branching, where next year’s fruit will develop.

Grapes

American grapes grow best when trained using the Four-Arm Kniffen System. This method helps create a strong structure for healthy growth and consistent fruit production.

  • Step 1: Set Up the Trellis
    Start by building a sturdy support system:

    • Stretch two heavy wires between posts spaced about 10 feet apart.
    • Place the top wire about 5 feet above the ground, and the lower wire about 2 feet high.
    • Plant your grapevine midway between the posts.

    Over time, you’ll train the vine to form a strong central trunk with four main arms extending from it.

  • Step 2: Prune After Planting
    After planting, cut the vine back so that only two buds remain above the soil line. This might feel drastic, but it’s essential for developing a healthy trunk and vigorous root system. When new canes grow to about 2 feet long, select the strongest cane and tie it loosely to a string that’s attached to the top wire.

    • This will guide the cane straight upward to become the main trunk.
    • Side canes that grow from it will later form the four permanent arms.

  • Step 3: Establish the Four Arms
    Once your vine’s trunk reaches the top wire, allow two canes to grow along each wire — one in each direction — to form four total arms.

    • Keep these arms evenly spaced for balance and good air circulation.
    • Remove any other shoots or canes that appear below the wire.

  • Step 4: Annual Pruning
     Each early spring, prune your grapevine to encourage strong growth and reliable fruiting.
    For each of the four arms:

    • Select two of the best canes and remove all others, including last year’s fruiting wood.
    • Tie one cane securely to the wire and cut it back to about 10 buds — this will produce fruit this season.
    • Cut the second cane back to two buds — this will grow into next year’s fruiting cane.

  • Step 5: Maintain Each Season

    • Continue removing any weak, damaged, or tangled growth.
    • Train new shoots to follow the same structure each year.
    • Regular pruning keeps vines open to sunlight and air — key for healthy, flavorful grapes.

Proper pruning is more than just cutting branches — it’s about guiding your plants toward healthier, more productive growth season after season. Whether for brambles, or grapes, the techniques you choose now can transform tangled, struggling vines into beautiful, fruitful specimens. Pay attention to timing, pruning cuts, and plant structure — and always remove weak, damaged, or overcrowded growth. With consistent care and a respectful approach to each plant’s needs, you’ll encourage stronger growth, better fruit, and easier maintenance in the long run. Happy gardening!