With the weird/warm/cold warm winter weather we’ve been having, it won’t hurt to prune deciduous trees that haven’t been done yet. Pruning trees and shrubs promotes new growth. Some of them are definitely operating off their normal season and it may take several years for them to return to their cycle after this wonky winter.
Generally, the task is to remove any dead or broken limbs and twigs, open up the tree to light and air, and reduce the overall amount of wood to encourage new growth. It pays to consult a good guide on pruning.
Different types of trees need slightly different methods. Most spring-flowering trees and shrubs bloom on wood from the previous year(s), so if you prune lightly on last year’s branches the current year’s production of flowers (and their fruits) will be affected.
Spring-flowering trees include: Redbud (Cercis canadensis and C. occidentale), flowering quince (Chaenomeles cultivars), saucer magnolia (Magnolia X soulangiana), trumpet tree (Tabebuia chrysantha and T. heterophylla), wisteria, fruit trees like peaches, nectarines, and plums.
Most years, roses don’t really stop blooming, so go ahead and prune them anyway. As soon as the warm weather comes, they will be bursting with new growth and it needs to come lower on the shrub from good strong canes not the thin top growth. Strip off old leaves, too, especially if they show any signs of disease, and bury them in the compost pile. Remember, the pile needs to heat up to really kill any pathogens, so if your compost has gone cold it’s time to turn it and add some more material to get it cooking again.
January is also the traditional month for applying dormant sprays, but if blossoming hasn’t begun (which it has for many early varieties) another round of spray will be okay. If insects such as bark borers or fungal pests like peach leaf curl or black spot have plagued fruit trees, use lime sulfur and copper sprays (like Bordeaux), but remember these are toxic substances and can affect the beneficial organisms in the ecosystem as well as the pests. Dormant oil sprays are safer and compost tea the safest of all. Be sure to get all the surfaces of the plant covered by using a sprayer that creates a fine mist. Spray just until the material begins to drip and don’t forget the trunk.
It may not feel like it, but spring is just around the corner in southern California. Some other gardening chores include:
•Plant bareroot trees and shrubs.
• Plant spring-flowering bulbs.
• Cut back perennials such as Tagetes, Salvia, and Leonotis for bushy new growth.
• Also cut down ornamental grasses to encourage new, vibrant growth.
• Direct sow seeds or start some indoors now, in pots or flats, for later plantings of snapdragon, cornflower, stock, poppy, nasturtium, and pansies as well as salad greens, carrots, beets, peas, onions, and turnips.
• Set out snail and slug traps: either shallow containers of beer or upended pot saucers or old boards. Check daily and dispose of the catch.
• Most plants are still growing slowly. Fertilize potted plants with half strength liquid fertilizer.