From: utzoo!decvax!microsof!uw-beaver!cornell!rej Newsgroups: net.garden Title: Re: soil acidifiers needed Article-I.D.: cornell.4355 Posted: Thu Apr 28 09:29:05 1983 Received: Fri Apr 29 21:09:37 1983 Oak leaves have a lot of tannic acid. Pine needles are also acidic. Therefore, compost including either of these will be quite acidic. I have found that needles take quite a bit longer to decay then oak leaves, so oak leaves make better compost.