Comfrey is a hardy plant that will grow easily from small pieces of root, so choose your location with care. You should select a permanent growing position as it has an expected life span of at least 20 years.
Before planting comfrey prepare the site by weeding and applying manure.
Preparing the area is important because in the early days of the comfrey plants growth, weeds will not only compete for water, nutrients and space, but will also increase the risk of plant diseases such as powdery mildew and orange rust. Although these problems rarely occur in established comfrey plants, young plants can be more susceptible if they become “stressed”. Maintaining good gardening practices from the start will decrease the chances of these problems emerging in the first place.
Most perennial weeds can be forked out by removing the whole root and composting in the usual way. Annual weeds can be hand pulled or hoed out after a good rainfall or watering, as this will loosen the soil and make the job easier.
After weeding and removing any debris from your chosen location, add a well-rotted organic manure; either plant based or animal based, both of which contain high levels of nitrogen and phosphorus. Both types of manure will increase the soil nutrients needed for the growth of healthy young comfrey plants. At this stage we don’t believe it is necessary to become overly concerned with which manures provide the best NPK values – this is a debate for later, for now it is just best to try and avoid any manures containing herbicides or antibiotics. Making your own manure or compost, or obtaining some locally, is one way to become more knowledgeable about the contents of your organic matter.
Using a garden fork, dig the well-rotted manure into the soil surface to a depth of 2 to 3 inches. Spread the manure generously and turn the fork so that the manure and the surface soil are evenly mixed. Leave the area to settle for a month or so to allow time for the nutrients to absorb into the lower level soil.
Avoid chalky soil.
Once your area is prepared and you have added some soil nutrients you can set about planting out.
Block plant the comfrey in full sun or partial shade about 2 to 3 feet apart with the growing point just below the soil surface.
Mulching is not strictly necessary however; it is important to keep the area around the young comfrey plants weed free by hand pulling or hoeing regularly.
Do not allow young plants to dry out. Water around the plant base and not directly onto the leaves where possible. The comfrey flowering period is between May and September. It produces a pretty pink/lilac curl of flowers which bumble bees adore. Growing to a height of approximately 40 inches – spread 30 inches. When harvesting comfrey use the shears and cut the plant to about 2 inches above the ground. Take care when handling comfrey and wear gloves, as the stems are covered in fine hairs which can irritate the skin.