pest control - If you have bugs or diseases in your garden and you want to get a head start, consider applying dormant oil (also known as horticultural oil) especially to roses, broadleaf evergreens and fruit trees. The oils are effective and ecologically friendly. They work by smothering the insects that are hiding out for the winter. Do not apply when temperatures are below freezing and apply when temperatures will be above freezing for at least 24 hours.
weeding - No, I'm not talking about on your hands and knees on the cold wet damp ground and pulling weeds. Instead, this is an excellent time to prune that invasive trumpet vine or honeysuckle that is threatening to take over your shrubs. There are plenty of warm sunny days for a chore such as this and it will be much easier now rather than waiting until the spring when everything is green again.
tool maintenance - Spring will be here before you know it, so get those pruners and lopers sharpened and the lawn mower serviced.
pruning - Fruit trees should be pruned now and other deciduous trees can also be pruned and shaped, if desired. Play it safe though and don't get too happy with the lopers.
feeding the birds - Once again, don't forget our feathered friends! Winter is a stressful time for wildlife and this includes birds. Providing well-stocked bird feeders is a must and even more important is providing water. Also consider putting a heating element in your fountain or bird bath so the birds can be assured a water source even in freezing weather. This is also a good time to clean bird feeders.
start keeping records - If you don't already do so, start a gardening journal or blog to keep a record of your garden. Keep track of when plants were planted, things that were successful and those that were not. Record where you purchased plants and tools. Make notes about the weather. Take photos of everything. In years to come, you will look at your older photos and be amazed at how things have changed!