I had mixed luck last year trying to nick or sand adansonia digitata seeds and just in experimenting this year with different processes across a variety of seeds found that hydrogen peroxide baths create clear soft spots in the shell that delaminate and sprout quite quickly after. It takes a little extra time but I had 94/100 successful seedlings this year on gregorii and look like I'll have similar rates on my digitata. What else works? Hydrogen peroxide is dirt cheap and I don't have to wear-and-tear my hands…
by MehtoMehMinus