using up old compost

thriftwizard

Apparently you can "rejuvenate" used compost with a mixture of coffee grounds (nitrogen) and wood ash (potash) mixed in, if you can lay your hands on a supply of both. I've done this this year & can report good results, though so far I've only used it for flowers & herbs, which don't require vast quantities of nutrients anyway!

Apodemus

thriftwizard said:

Apparently you can "rejuvenate" used compost with a mixture of coffee grounds (nitrogen) and wood ash (potash) mixed in, if you can lay your hands on a supply of both. I've done this this year & can report good results, though so far I've only used it for flowers & herbs, which don't require vast quantities of nutrients anyway!

Hmmm...  I'm with you on the wood ash, but less sure about the coffee grounds.  Coffee grounds are about 2% Nitrogen.  The science suggests that grounds can help feed bacteria and aid decomposition of plant material when added to a compost heap or soil but are not accessible as a nitrogen source for plants themselves when added directly to growing medium.  So they can have benefits for soil fertility but it is good to add additional nitrogen alongside the coffee grounds as the enhanced bacterial decomposition that the coffee grounds feed, can also temporarily deplete the available nitrogen for the plants themselves.