COMFREY, true from seed VS russian sterile?

This year, I want a lot of comfrey growing at the farm, I mean A LOT. I have a few different sources for the Russian Sterile (only spread via roots) but that would only be 1-5% of what I want to grow... because I tend to be a little impatient, I went ahead and ordered a lot of seeds from Richters Herbs. Everyone seems to be so afraid of Comfrey, and I know it can take over quite quickly ... my questions are:

Will true comfrey also spread via root division^? Will it come back the following year if I dont let it go to seeds^?
Will it be possible to stay on top of my patch (will use for chop and drop, teas, mulch) and not letting them go to seeds? or is it too hard to prevent em from spitting seeds everywhere once they start flowering because they grow so fast?

I have 40 X 200ft long veggie rows and I plan to have a patch of comfrey that is along the driveway for the width of the 40 rows by about 10 ft or so, so around 2000 sq. ft. of comfrey in that one location.

Comfrey can set flowers several times a year, you would really need to stay ahead of it with consistent mowing to avoid any seed set. I think doing it by hand, it would be easy to fall behind, and consistent mowing will encourage grass.
The sterile varieties are so easy to propagate, that after a year or two, you could easily make over 1,000 root divisions from a handful of plants.
If you're interested in bulk rates for sterile comfrey roots, I can sell or trade for them. For 200 roots, I ask 40 cents a piece, and for 500 roots, it's 30 cents.

While the idea of growing lots of comfrey is great I would be very reluctant to spread seed setting types on my land. While you may be willing to mow every comfrey plant 5 times per year, are you always going to be able to do it? What about when your mower breaks down? Or you break a leg? or you sell the property and someone less proactive and knowledgeable takes it on? Or you spend the next 40 years there, grow gracefully old and don't have the energy to handle the labour?

Sterile comfrey is totally labour free - you can plant it and totally ignore it. The leaves will grow, fall to the soil, break down and fertilise year on year with no more effort on your part - not even with any need for "chop-n-drop". Planted densely around fruit trees they will supress grass and dynamically accumulate - again, with no need to mow. I originally planted 6 plants 3 years ago. Last year I divided just one of them and easily had roots sections for another 30. My advice would be either - don't be in such a rush and make divisions yourself over a few years - or buy varieties known to be sterile in bulk for immediate planting.

I guess you need to ask yourself what decades of regular slashing/mowing are worth to you? Think about it as a trade off - if you had that time available you could add another income stream to your smallholding. Beekeeping seasons overlap pretty much with prime comfrey mowing time for example; you could setup and manage half a dozen hives with that time!

2000 square feet isn't that much, easy to do with cuttings.

Toby Hemingway has a method for propagation I like. Rototiller! Plant them in the bed evenly as dense as you can afford. Then after they are established, run the tiller through the bed and then you have a full bed of comfrey. One time the tiller can do good.

Finding bulk cuttings can be a challenge, but I have had good luck with any I bought from permies members (bought from several, don't remember who).

Thanks a lot! so true comfrey will also spread via root division and even if not allowed to go to seed it will stay in the soil and come back year after year^? What do I do with all the seeds I ordered!! Guerilla plant them^? throw them on my enemies lawns? ( joke, I have no enemies! that I know of )

Akiva, I would like to buy some of your roots

I'd probably throw 'em in the woodstove, or hit them with a hammer while laughing maniacally...pretty much anything but planting them.

Why is that Jessica? 0)

From everything I've heard about comfrey that makes viable seed, I don't want it anywhere near my gardens. It seems easy to find sterile rootstock (which is what I did, locally sourced) so as to avoid something so invasive. I've got plenty of other invasive pests to worry about without adding to the mix.

Is it edible? Maybe I'd eat it...the maniacal laughter is mostly for the theater of it...

How cold hardy are they? Both the sterile and seeding.
I'm in zone 3 with variable winters. I know people grow it as an annual here, but don't know anyone that grows it every year.

I have to put fences around my trees to keep the sheep and dogs away from them. I would love to plant the sterile variety around the trees so I don't have to trim the grass inside the fences.

Miguel DaStein wrote: if I dont let it go to seeds^?

No flowers = no bumblebees.