|Flowers in picture are larger than they appear.|
But other than giving CNN another Russian conspiracy to expose, why would someone want Russian comfrey growing about the yard or garden? There are actually a couple of uses for this plant besides getting the bees in the habit of visiting your place in early spring.
The first is, as I've mentioned here before, as a mulch. Comfrey has a very deep taproot, through which it pulls up lots of vitamins and potassium, storing all that minerally goodness in its broad leaves. Broad leaves make great mulch, keeping the weeds at bay and the ground moisture in place. The one downside of comfrey leaf mulch is that the leaves break down so quickly that you have to constantly re-apply them unless you mix them with other leaves and stuff. Then again, re-applying often means you're getting more good stuff in your soil.
That quick breakdown helps the second use: comfrey tea. Not for you to drink, mind you, but for your tomatoes and other nightshades. When comfrey leaves break down, they liquefy* and release all their potassium goodness in a form that gives tomatoes a boost. I don't like using commercial fertilizer, so any time I can create lots of natural if stinky fertilizer I try to do so.
Comfrey also grows like crazy, creating lots of seedless** bulk for your compost pile. But if you don't chop it down for compost it grows into a very tall and decorative flowering herb that's often featured in flower gardens. It's nice to look at, if you like that sort of thing.
One final attribute that I have not personally verified is that it has lots of medicinal uses -- one of its alternative names is 'knitbone'. Comfrey has long been used as a bandage for external injuries and a poultice for internal ones. While I'm not expecting to have to knit any bone together myself in the near future, it's always good to have the stuff on hand to do so, I guess.
* and putrefy. You wouldn't want to drink comfrey tea anyway.
** Comfrey actually has seed, but the Russian variety is sterile and spreads via root only.