December is coming in with a cold bang... my apple trees still have their leaves and the temperatures have dipped into the low thirties and even twenties at night. Yet it is blessedly dry and a great time to add compost to your trees. I like to use mushroom compost I purchase from Mt. Scott Fuel, www.mtscottfuel.com. I like to put at least a wheelbarrow full around the drip line of all my trees that are now 5 years old. You can definitely put on more but aim for about a 1 inch layer all around the drip line. The winter rains, at least in Portland, will bring the nutrients to the trees roots. Now is a great time to lime as well and I would apply the lime before the compost. For older trees (5+ years) use about a pound of lime spread evenly about the drip line. For younger trees, a cup to two cups spread evenly about. It is really hard to apply too much lime, especially here in the PNW, so don't worry about putting on too much.
The benefits of using mushroom compost are a) it is sterile and weed seed free, b) made from cow manure instead of horse manure (horse manure is notorious for having large amounts of weed seed because horses can't digest weed seeds unlike their ungulate brethren),and c) it has added bits of lime, sand, and other micronutrients that I like.
Other than that, my winter projects are to make persimmon vinegar from our bountiful crop of Fuyu and Hachiya persimmons as well as making dried persimmons and persimmon leather. Drying Hachiya persimmons when they are still hard will remove the astringency that they are notorious for.
Okay, enjoy the sunshine will it lasts.