Hello. I would like to use pine needles, or pine straw or any other conifer needles as mulch for my maples this fall. Are these commercially available, as pine bark for instance is? If not, I could go and find the necessary amount in the woods, by collecting them off the ground. My question is: is this a danger insofar as these could have a dormant virus/disease I'd pick up at the same time? Do they need to be cleaned/wahed? Thanks for any reply.