Once established, comfrey is an easy plant to care for. It has 3 basic requirements:
Comfrey is somewhat drought-tolerant, but beds with young plants should not be without water for more than 3-4 days, especially in hot, dry weather.
Over-watering is not a major issue for comfrey in beds. In pots, allow the soil to dry out somewhat before watering. The signs of over-watering pot-grown comfrey is a lightening and yellowing of leaves.
Comfrey’s rapid growth potential signals its nitrogen-greediness. To get the most from your comfrey patch, feed it regularly and liberally with animal manure.
This should be applied as a top-dressing around the plants, as a mulch or lightly dug-in.
The manure can be somewhat ‘hot’, but not fresh unless it’s the dormant season. Well-rotted cattle or equine manure mixed with poultry manure is the best food for comfrey.
Over-winter we apply a deep mulch of fresh manure covering the beds completely.
If you do not have a ready supply of manure there are alternatives:
- A mulch of grass clippings. We use grass clippings in early summer – they provide an effective nitrogen source, retain moisture, and act as a weed-suppressant. Apply several inches deep, and dig-in lightly. You can repeat this weekly if the weather and conditions are favourable.
- Leafmould – making your own leafmould is easy, and in most places leaves are readily available in the autumn.
- Home-made compost – will provide many of the same benefits.
- A commercial feed, such as growmore or equivalent. This is a last resort – if like most growers you’re growing comfrey to make feed, it doesn’t make a lot of sense to buy a product to feed your comfrey.
Mature plants should be cut at least twice per growing season to keep them healthy. See our guide to harvesting comfrey for more information.