Happy New Year! January is the big planning month, with resolutions, goal-setting, dreams, and budget-making. Even in our Mediterranean climate, in which most of us are not buried in snow in January, it is still a great month to add garden planning to our general list. The days are short and with frost likely many nights, it is a month with some specific types of tasks to do, but generally fewer chores than our busy autumn and spring seasons.
What to plant:
This is bare root season, so it's time to go shopping. Shop early before they get picked over. Local nurseries carry varieties suitable for our planting zone — if you buy from a catalog, be sure to research whether your choice is suitable for our area.
- Bare root fruit trees — Apples, apricot, cherries, figs, pears, plums and many others are now available. Check their pollination requirements; not all fruit trees are self-fertile, and some will require a cross pollinator. Notice the number of chill hours required. Our winters average 700-800 chilling hours. We are in a climate trend towards fewer chill hours, so you can try one of the newer “low chill hours” trees, but one of the things that make our valley unique in California is the greater extremes of heat and chill that tends to make for better fruit flavor and quantity. So weigh your options, and perhaps try a range of trees.
- Bare root roses — Hybrid teas, floribundas, climbers, miniatures, and shrubs are available. All do very well in the San Joaquin Valley. Many new varieties actually require less water than their ancestors, so they are worth looking into as we continue to plan and create our new California drought-tolerant gardens.
- Bare root berries and grapes— Plant grape vines, cane boysenberries, blackberries, raspberries, blueberries and strawberries. There is nothing like fresh-grown berries, and they are so easy to grow. Our website has lots of specific information, and don't be afraid to ask the Master Gardeners for advice!
- Vegetables — Asparagus crowns, artichokes, horseradish, lettuce, peas, and rhubarb can be planted now. Hold off planting new citrus or sub-tropical plants because of the potential for frost damage. Better to wait until spring. You can plant any cool-season vegetables, but growth will generally be slow unless you use row cover cloth, hoop houses or another method to keep the soil and air temperatures warm.
Dormant sprays — Time to spray roses, deciduous flowering trees, and deciduous fruit trees with horticultural oil to smother overwintering insects like spider mites, scales, mealy bugs, and peach twig borers. Spray the branches, crotches, trunk, and the ground beneath the tree's drip line. Hold off spraying if rain is forecast, or if the temperature is below 45 degrees. Never spray oil on walnut trees. If you didn't spray your peach or nectarine tree for peach leaf curl in November or December, spray now with a copper-based or a synthetic fungicide. Read and follow package directions for safety and best results.
Water — Adjust your controllers and faucet timers to reduce watering in the winter months. Fog, dew, shorter days and cooler temperatures all mean less added water is needed in winter by our gardens, even if the precipitation is not abundant. But be prepared to add water during extended dry spells (a week or more). Even dormant trees need some water in the winter, and our climate-adapted plants require adequate moisture during winter and early spring to establish and succeed through the hot summer months. Check the soil moisture at the root zone a few times until you get a feel for how much to water. The soil should remain fairly moist at the root zone, but not water-logged or muddy.
Lawns — Mow cool season grasses, such as fescue, at 1.5 inches (slightly lower than in the summer) to reduce disease problems. Try not to mow when the grass is wet or frozen to avoid compaction. Start thinking about controlling summer weeds (Already? Yes!). If you were plagued with spurge and/or crabgrass last summer, then apply a specific preemergent herbicide to kill seeds as they are germinating. For best results, apply uniformly over the entire area late this month. I usually do it just before Super Bowl Sunday. Do not use preemergent anywhere you have planted seeds or seedlings recently, or where you might plant them in the next several months.
Tool care — Sharpen, clean and sterilize your tools. If you don't have time to do them all, at least work on your pruning tools, so you are ready for the next task.
Prune — Dormant deciduous plants such as fruit trees, roses, and grapes should be pruned after leaf drop and before buds swell, so a clear sunny dry day in January is great for this. Put on the caps and gloves and get outside. I love winter pruning on these types of days. I also love pruning on foggy chilly days. It's enjoyable, to begin with young trees and shrubs and train them over the years! Sterilize pruning tools after every tree or shrub to avoid spreading diseases. A weak bleach water solution (1:10) or white vinegar in a spray bottle, along with a clean cloth or spray of plain water works well.
The most basic pruning is to remove broken, diseased, or crossing branches. Beyond that, there are two types of cuts: thinning and heading. It's not that mysterious. Think about your cuts before you make them. Thinning cuts remove entire branches, resulting in a more natural look, air circulation improvement, and light into the center of the tree. Heading cuts stimulate many weak branches to vigorously sprout, creating an unnatural look. Begin pruning with thinning cuts to open up the tree. Use heading cuts judiciously to shorten over-long branches, and make a note that you will need to address those inevitable weak branches later on. If you do heading cuts, note the direction the bud is facing; that is the direction most of the new branches will head, so direct them outward. Prune from the bottom up and from the inside of the plant to the outside. We have more information on our website.
The worst time to prune is right after the leaves emerge in spring, so don't delay. January is also too late to prune spring-flowering shrubs. If you prune now, you won't get many (or any) flowers. Wait to prune spring-flowering plants like forsythia, lilacs, Ceanothus, lavender, sage, and manzanita until they have finished blooming.