By the end of the month most for the leaves have fallen from the deciduous trees. Hopefully you will compost them or rake them into areas where grass won’t grow or where you have planted fruiting shrubs. Blueberries do well with nothing but pine straw and no fertilizer. Mixing non-protein, non-fat food scraps with leaves in a more or less 1:4 ratio makes good compost. Compost is the best thing for the garden. It is a valuable free resource, so put your leaves in the garden or compost; not at the curb.
Most herbs can be planted now: Oregano, rosemary, sage, thyme, cilantro, dill and fennel could be planted now. Cilantro and dill should be protected from the freezing temps. Just to be sure, I cover everything in the herb plot. If you don’t buy herb plants, seed starting for herbs is best done indoors in a sunny spot or in the green house. This is because the ground is cold, germination is slow, and seeds often rot before they produce a seedling.Vegetables like asparagus, arugula, cabbage, chard, spinach and lettuce could also be planted in December. The same recommendations for herbs applies here. You still have time to get your onions plants and sets planted. If you do not have shallots in the garden and have to buy them for the kitchen, you can cut off one inch from the butt end and plant the butts in the garden. This way you have scallions for up to three years by cutting the tops off at ground level. The scallions will grow again for many cuttings.
Strawberry plants can be planted throughout the month, and should be well mulched. It is also time to plant bare root blackberry plants, fruit trees, and berry bushes.Remember to water well before a freeze, keep the garden well mulched, and for sustained or hard freezes, cover with row cover, sheets, or plastic. If you use plastic, do not let it touch the plant or the leaves will freeze where the plastic touches them. Black plastic works better than clear. This is because it blocks infrared radiation into the clear sky better than plastic that is not opaque. This is also true of frost cloth. Of course cloth is a better insulator than plastic. Be sure to remove the plastic frost cover before it gets too hot underneath and cooks your plants.
The official start to winter is Dec 21st and the days will become shorter, which means shadows are long and sun shines for fewer hours. The good news is that days will ever so slowly become longer until the summer solstice.