Russian Comfrey 'Bocking 14'

The Bocking 14 cultivar of Russian Comfrey is a variety that can only be propagated from root, not from seed. It is an attractive ornamen...Read Moretal crop when regularly pruned and folks who see it for the first time always inquire about it. I grow it for use as an activator and nitrogen source in compost bins, foliar fertilizer, and as an ever-ready mulch whenever needed. The leaves are high in potassium (5.8%), nitrogen (3.5%) and some phosphorus (0.5%), so I grow quite bit of it, having two main beds which are harvested at least 4 times per season.

As a mulch, the leaves quickly degrade. In general, big stems should be composted as they contain quite a bit of water. Although each plant can produce apparent bulk, it takes a lot of comfrey to provide for a compost bin since the leaves degrade so quickly. When mixed with dried leaves from hardwood trees, comfrey leaves helps to accelerate the production of leaf mulch when the mixture is kept moist, not wet, in a plastic contractors bag or other closed container.

If properly planted, comfrey is as no-maintenance as one can get in gardening. It has no persistent pests in my garden, perhaps because the leaves have little spines that can be irritating to insect and humans alike. It is one of the first to appear in spring and will grow quickly if moisture is sufficient, providing an early nectar source for bees. Bumblebees are particularly fond of it.

There are few guidelines to observe before and after planting:

1. Select a permanent location before planting. Comfrey has a deep taproot and relocating is a chore. Any piece of root that remains will produce a new plant. I was able to relocate my first plants using a garden fork, but did so before the season ended when the roots were still within the first 12 inches of soil. The good news is that the taproot mines deep for nutrients making the plant self-fertile and enriches the leaves.

2. When planting, space the roots at least 3-feet apart, giving the root ball of each plenty of room to expand. The plants will quickly fill in the air space.

3. Always wear long sleeves and gloves when handling the leaves, which can be very irritating, and especially to those with sensitive skin. This is ironic in that comfrey is heralded as a poultice. If cut and left in the sun for an hour or so, however, this characteristic dissipates, and when placed in hot water, it goes away altogether. You can tell which leaves are free of the spines by their limp, dull green, almost grayish, appearance. It's still a good idea to keep it off your skin.

4. When harvesting leaves for a foliar feed, cut off as much of the large stems as possible, have your water already boiled before harvesting, pour the boiling water over the leaves, cover your container, and let steep until cool. You should have a moderately bright green liquid. Mix one cup of the liquid to a gallon of water and spray under the leaves. For best results, add a teaspoon of soluble kelp or fish hydrolysate and an equal amount of Epsom salt if desired.

5. If not harvested, the plants will fall over and look untidy, but other than appearance, the plant is fine. However, this environment makes a wonderful home for grasshoppers and crickets among others. Best practice: harvest often after the initial flowering in spring.

6. I mulch comfrey with straw in order to promote bed moisture and suppress weed growth between cuttings. Comfrey likes a very moist soil, and is known to thrive in bogs, but Bocking 14 will tolerate drought, falling over during high heat, quickly recovering over cool nights. However, if this is a persistent pattern, the leaves will lose their nutrient vitality. You can tell this is so by their rather lipid appearance and part of the worst affected leaves will have partial decay. If you want a nutrient rich crop, water as you would any drought tolerant plant. That is, when it is dying of thirst, give it a drink.