Uses of comfrey manure
Comfrey manure is mainly used to increase the potassium content of crops, although it also contains small amounts of nitrogen and phosphorus. Comfrey manure is often combined with nettle manure for a more balanced NPK (nitrogen, phosphorus, potassium) contribution.
Simply put, potassium (or potash) is a “booster” for flowering and fruiting. It is therefore used when flowers are in bud, or at the start of fruit set.
Preparation time
15 min
Ingredients
- 1 kg of comfrey tops. Don’t be afraid to cut flush with the ground: comfrey grows back quickly. When should I harvest? You can harvest whenever you like, but ideally just at the start of flowering. This prevents comfrey from re-sowing (because it is rather invasive).
- 10 l water, ideally non-chlorinated (e.g. rainwater)
Curing time
10 to 15 days
Preparation
- Harvest and weigh 1 kg of comfrey
- Roughly cut the comfrey (here, several techniques are valid; for my urban gardening purposes, I like to use long-bladed shears in the container I’ll use for the liquid manure).
- Add water
- Stir and cover. The lid must let in air, but not insects or dust. You can make small holes in it, covered by a mosquito net or a cloth. An unsealed lid also works.
- When there are no more bubbles, filter and store in a cool, dark place.
- Dilute before use
Concentration of comfrey manure according to use
Use the solution diluted to 10% for watering and 5% for foliar spraying. Foliar spraying is a bit like giving the plant potash intravenously. The result is faster, but the most sensitive plants may not like this shock treatment!
Recycle your comfrey for compost
After filtering your comfrey, recover the macerated plants for your compost. Nutrients remain, and with all the micro-life that produced the purin, they are excellent compost gas pedals.
Frequency of application of comfrey manure
A single watering when the first flower buds appear, and sometimes a2nd watering at the start of fruit set.
In the vegetable garden, tomatoes, celery, cabbage and potatoes, as well as melons and watermelon, benefit most, but roses, clematis and many other ornamental plants will appreciate comfrey manure, especially for subsequent flowering.
Take care
- Use gloves and goggles when handling liquid manure.
- Take care to respect the maturation time and concentration, as over-concentrated liquid manure can burn plants.
- Never apply foliar sprays in bright sunlight, but rather in the morning or late afternoon.
- With a concentration of 10%, take care not to water the foliage, but target the soil around the plant to nourish the roots.
Conserving comfrey manure
Stored in a cool, dark place, your concentrated liquid manure will keep for around 6 months. Once diluted in water, it won’t keep: water and feed your soil with your leftovers.