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Blackberry · Rubus

Why are my blackberry canes growing so long and leggy?

It is less common for blackberries to become leggy, and this usually happens because they are reaching for more light or have been given too much nitrogen fertilizer. Check if your plant is getting the full sun it requires.

leggy growth on a plant
Photo: Rosser1954, CC BY-SA 4.0

Check these first

  1. Verify the plant is getting at least 6 hours of direct sun.
  2. Check if the canes are being supported by a trellis.
  3. Review your recent fertilizer application history.

Likely causes

  1. Low light levels

    Most likely

    How to tell: The canes are thin, weak, and stretching long distances between leaf nodes. The plant leans heavily toward the nearest light source.

    What to do: Relocate the plant to a spot with full, direct sun. If the plant is already in the ground, prune back the longest canes to encourage branching and sturdier growth.

  2. Excess nitrogen

    Possible

    How to tell: The plant has lush, dark green foliage but the canes are soft, floppy, and grow too rapidly. The plant struggles to support its own weight.

    What to do: Stop using high nitrogen fertilizers. Switch to a balanced, slow-release fertilizer and ensure the canes are properly trellised to provide structural support.

Find out what's wrong with your blackberry

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

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When to worry

It is normal for blackberry canes to grow quite long as they are naturally vining plants. Worry only if the canes are so weak they cannot stand or if the plant is failing to produce fruit.

Stopping it coming back

Provide a sturdy trellis system early on and ensure the plant receives full sun throughout the day.

Keep your blackberry healthy from here

Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked. Identification and a health check are free.

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Questions people ask

Should I cut back leggy canes?
Yes, you can tip back the canes to encourage side branching and a more compact shape. Do this during the growing season to manage the size.
How do I support my blackberry canes?
Use a wire trellis or wooden stakes to tie the canes up. This keeps them off the ground and improves airflow, which helps prevent disease.

More problems with Blackberry

Back to the Blackberry guide

This article was generated with AI from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.