Comfrey

This plant serves several purposes in my backyard orchard.   

1. It has large roots that can grow into hard packed clay soils.  This will help loosen compacted soils and improve water absorption.  A 1 inch root cutting can be planted by making a slit in hard clay with a shovel, pry open the slit with the shovel, drop in the root cutting, remove the shovel and press closed with your foot.  It will grow!  It may take 4 weeks and some rain but it will grow into a plant. 
2. The plant grows very large and produces lots of biomass.  The leaves shade out grass.  The leaves can be cut and used as a green mulch or added to the compost pile.  It is rich in nitrogen and when composted makes an excellent fertilizer. 
3. Comfrey will bloom with purple flowers that bees love.  This is an excellent plant to attract bees with. 

Comfrey is very hardy and hard to kill.  I planted a hybrid that is sterile.  The flowers do not produce seed.  If seeds were produced these would be invasive.  

Comfrey has various uses as a medicinal herb.  I have no experience with this.   

Here is a podcast episode on comfrey by Jack Spirko from The Survival Podcast. 
Episode-93- TSP Rewind – All About Comfrey the Miracle Plant

Here is another good source for info on comfrey by someone who grows and uses it.  https://preparednessmama.com/growing-and-using-comfrey/

Below are photos of Comfrey growing in my backyard orchard.