The comfrey you need for the garden is Bocking 14 which doesn't grow from seed. If you need root cuttings I will happily send you some if you pay the postage. It's wonderful stuff - you make a liquid feed (your granddads tea), you can chop it and use it as a mulch, you can dig it into tomato planting holes, add it to the compost heap or use it to enrich bought growing compost. It is also very good for sheep who like to graze the young leaves and of course the bees and other beneficial insects absolutely love the flowers. So if you want some roots (I have masses ) please pm me.