How To Grow Comfrey

Comfrey isn’t just a hardy perennial, it’s one of the most useful plants in any organic or no-dig garden. It improves soil health, feeds other plants, and supports masses of wildlife. It’s low maintenance, grows almost anywhere, and pays back tenfold what little effort you put in.

What Is Comfrey?

Comfrey is a deep-rooted plant in the borage family. It produces broad, hairy leaves and clusters of bell-shaped purple or pink flowers. It’s a perennial, meaning it comes back year after year once established.

The variety most gardeners use is ‘Bocking 14’, a sterile cultivar developed for its non-invasive nature. This is important as regular comfrey can be a real bully and quickly take over.

Top Benefits of Growing Comfrey

Natural Fertiliser Powerhouse

Comfrey leaves are rich in nitrogen (N), phosphorus (P), and potassium (K) – the key nutrients needed for plant growth. That makes it ideal for:

• Compost activator – Speeds up decomposition in your compost heap.
• Mulch – Laying leaves directly on the soil feeds and protects it.
• Liquid feed – Comfrey tea rivals shop-bought tomato feed and costs nothing.

Its deep taproots bring up minerals that other plants can’t reach, concentrating them in the leaves. When those leaves decompose, the nutrients are released into the topsoil, a natural way of improving your soil.

Soil Structure and Regeneration

Comfrey puts out huge tap roots; these roots break up compacted soil and improve drainage. Over time, they build better soil structure, particularly useful in heavy clay or neglected ground.

It also helps regenerate tired ground. Plant comfrey in areas where soil quality is poor, then cut and compost it in place. It’s a brilliant way to rebuild fertility in spent beds.

Super Easy To Grow

It’s rare to see comfrey bothered by pests or diseases. Slugs don’t touch it, and its tough leaves resist most damage. That makes it an ideal companion in tougher parts of the garden, especially near compost heaps, fences, or chicken runs.

Comfrey mulch can also suppress weeds around other plants while feeding the soil. Just plant it and forget about it until it is time to harvest those prized leaves.

Supports Pollinators

Comfrey flowers are a magnet for bees. If left to flower, it provides valuable nectar through spring and early summer. This supports pollinators and boosts productivity elsewhere in the garden.

To get the best of both worlds, let a few plants flower and cut others for feed. Or stagger your cuts to provide blooms and biomass.

How to Grow Comfrey

Pick a spot where you want to grow your comfrey. It will do well in most areas so you dont need to overthink this. Most gardeners will use a waste area that isn't in production as the perfect comfrey patch.

Comfrey thrives near compost bins, behind sheds, or along borders. It doesn’t need prime space but does best where it gets at least some sun.

Planting Tips

Comfrey plants are commonly sold as either crown cuttings or root cuttings. Crown cuttings are a little more expensive as they are quicker to establish themselves and get growing.

Planting is incredibly simple; just stick them in the ground. If you have root cuttings, then they will just be a chunk of root that you need to bury and then let it do its thing, That's what I mean when I said earlier that this was a simple plant to grow.

How to Harvest and Use Comfrey

Chop and Drop

Once your comfrey plants reach around 60cm tall, you can start harvesting. Use a sharp knife or shears to cut leaves about 5cm above the ground. Expect 3–5 good cuts per year once established.

One of the simplest ways to use comfrey leaves is chop and drop, which is exactly what it sounds like. Leave the cut leaves as mulch around tomatoes, potatoes, squash, or any hungry crops. As they break down, they’ll feed the plants.

Comfrey Tea (Liquid Feed)

1. Fill a bucket with comfrey leaves – no water needed.
2. Weigh them down and cover the bucket.
3. After 3–5 weeks, a thick black liquid will collect at the bottom.
4. Dilute it 1:10 with water before applying to your plants.

Store in a bottle with a lid, the smell is strong, so keep it outside.

In the Compost Heap

Comfrey acts like a compost turbo. Mix in layers of chopped comfrey with browns (like cardboard or dead leaves) to balance the nitrogen and speed up decomposition.

In Your Water Butt

This is an allotment staple. Add a few comfrey leaves to your water butt. They will break down over time, adding a consistent but weak feed to your water.

Managing Comfrey Long Term

Cut regularly to stop it getting unruly. Bocking 14 won’t spread by seed, but if you dig into the root, fragments may regrow. Best not to plant it in the middle of your veg beds.

A few plants go a long way. Two or three will supply enough mulch and feed for a medium-sized garden.