how big does comfrey grow

Does comfrey spread easily?

It is an extremely tolerant and resilient plant. Suitable for perennial cultivation in USDA Hardiness Zones 4-9, it is not very sensitive to soil conditions or pH, and it spreads rapidly. There is no need to worry much about weed control, because comfrey's large, quick-growing leaves will shade them out.

Does comfrey come back every year?

Extremely cold hardy perennials, comfrey plants become dormant in winter and re-emerge every spring.

How fast does comfrey spread?

Strong, mature plants on a 3 foot grid will have the larger outside leaves touching the adjacent plants after 4 to 5 weeks growth. Comfrey can also be grown indoors, in pots (1 to 5 gallon size) for a continuous harvest of fresh, small leaves.

Does comfrey spread by roots?

Many people worry that comfrey will become invasive and spread. Our comfrey does not produce viable seed and stays in place. It will only spread if disturbed because any piece of comfrey root will make a new plant. So any digging or rototilling near comfrey will result in new plants.

Is comfrey toxic to dogs?

The Merck Veterinary Manual lists comfrey as an especially risky herb because of its pyrrolizidine alkaloids, which have been linked to liver damage. The alkaloids are actually produced by the herb to fend off bugs, but the insecticide can be harmful to a dog.

Where is the best place to plant comfrey?

Comfrey can grow in full sun to partial shade, meaning it needs at least three hours of direct sunlight on most days. In the warmer parts of its growing zones, plant it where it will get shade from the strong afternoon sun.

Should comfrey be cut back?

In the first year (second for autumn planted) allow the plants to grow to the point where it throws up flower stalks and then cut back to about 15cm (6″) from the ground. Leaving the cut leaves on the ground as a weed suppressing mulch will return some of the goodness back to the plant.

Is comfrey good for the garden?

Comfrey is the organic gardener's best friend. Its leaves are full of nitrogen, phosphorus and potassium - all nutrients needed by growing plants. Master the use of comfrey and you'll never need to buy expensive fertiliser again.

Does comfrey have deep roots?

The Comfrey has deep roots of up to 2 m that utilize nutrients deep in the subsoil that would otherwise wash away with the underground soil water or remain inaccessible to other plants.

Why did FDA ban comfrey?

The pyrrolizidine alkaloids in comfrey can cause severe liver damage, liver cancer, mutagenicity, and even death. [8,9] For this reason, the U.S. Food and Drug Administration has banned the sale of oral comfrey products in the United States.

Are borage and comfrey the same thing?

Though they are members of the same plant family (Boraginaceae), perennial comfrey (​Symphytum officinale​, USDA zones 4-8) and annual borage (​Borago officinalis​) are two different plants. These cousins both boast dark green foliage and fuzzy leaves.

How do you stop comfrey from spreading?

However, comfrey will often take over wherever it is planted. In order to solve this problem, consider planting comfrey in a container or creating a solid barrier to prevent it from spreading. Also, as a perennial, though comfrey will die back in the winter, you can expect it to return even more generously each spring.

Should comfrey be cut back?

In the first year (second for autumn planted) allow the plants to grow to the point where it throws up flower stalks and then cut back to about 15cm (6″) from the ground. Leaving the cut leaves on the ground as a weed suppressing mulch will return some of the goodness back to the plant.

How long does comfrey fertilizer last?

How long does Comfrey fertilizer last when stored? If you make the concentrated fertilizer it will last for around a year. So you could make one large batch and store it until it is required. If making Comfrey fertilizer with water then this should be used as soon as it is ready.

Does comfrey improve soil?

Comfrey's roots break up heavy clay and creating channels for aeration and better water absorption, similar to dandelion roots. Over time, its decomposing leaves and roots enrich and condition the soil. This dual action of decomposing leaves and roots can help improve marginal land.

What is the difference between comfrey root and comfrey leaf?

The root has a black outside and fleshy whitish inside filled with juice. Comfrey preparations are made from the leaves or other parts of the plant grown above the ground. New leaves tend to have more of the poisonous pyrrolizidine alkaloids than older leaves.