Oak leaf mould

"Leaf mould" is popular with European crypt growers so I've started putting oak leaf mould into my mixes.  Leaf mould is just the humus from composting leaves.  A few initial trials on emersed varieties of Crypt. undulata have been really good with improved growth rates and healthier looking leaves over just using peat moss and sand.  The leaf mould starts as raked up oak leaves in a cut down barrel that has no bottom where they compost down.  I keep adding to the top and stiring it occasionally.  When its ready I pass the broken down leaves through a 5mm garden sieve, keeping the smller fraction and returning bigger leaves to the barrel.

I've been using the oak leaf mould to replace some or all of the peat moss in a mix that is about 40% peat/oak, 50% sand and 10% red clay and shell grit.   We don't have many "blackwater" crypts in Australia that grow in pure leaf mould, but if they ever get here I'm ready.

Update: May 2017.  The pH of the mix is approx 7.2 so not acidic at all and not the best for the true blackwater crypts.  I certainly do think its benficial to the mix, but for species that need pH <6.0 this isn't going to do it... at least not in the form it is here.  I've got some in jars with Crypt cordata that have been festering as a slurry with water for a longer period of time and these are more acidic.  It might take a couple of months in water for the organic acids to really do their thing.