Your Winter Garden
Spending time in your garden in January will include many things such as great vegetable and flower selections, frost and freeze prevention and pruning maintenance – that’s the short list. Your winter vegetables and flowers were planted a couple months ago and will only need some fertilization this month along with new plantings for fresh harvests. So chances are what is top of mind is probably the ugly plants the freeze created in your yard.
If freezing temperatures affected your area recently you may have some plants that are either frost damaged or dead. Frost damage is evident when leaves become discolored after a frost and usually they turn black. If enough of the plant is damaged, it may not recover. If plants are damaged by frost, DON’T prune them! The damaged branches will actually add protection from additional frost damage for the duration of winter. If you cut that off, future damage can occur to the newly exposed branches. Wait until all frost is over to cut the damaged areas back. In the Valley, that is around the beginning to the middle of March.
There are several ways to protect your plants from future damage. Gardener’s Eden recommends using a geo-textile fabric, such as Frost Blanket, to cover plants. Frost Blanket gives 7 to 10 degrees of frost/freeze protection. We recommend against using burlap, bed sheets or plastic. Burlap is too heavy and messy (fibers) plus the fibers are open and loose; bed sheets are too thin and only give a couple degrees of protection; and plastic doesn’t breathe. Frost blanket can be left on during the day since it allows in light and water and frost blankets don’t allow the warmth from daytime heating to escape. Frost blankets are economical and can be folded and stored to be used for many years to come.
We also recommend using a non-toxic liquid polymer called Anti-Stress 2000, that’s mixed with water and sprayed on leaves for an additional 5 degrees of protection. Once applied, it is active from 45 to 60 days. Anti-Stress 2000 can be used on edible plants, but no later than 45 to 60 days before harvest; but we generally recommend against using it on edible plants. You get best protection when Anti-Stress is applied 24 to 48 hours before frost is predicted. This product is particularly helpful when hard freezes are predicted and to protect fruit blossoms from frost.
Several common landscape plants need protection from winter freeze and frost. Below is a partial list of frost sensitive plants:
Thevetia (Lucky Nut Tree)
All varieties of Carissa (Natal Plum)
Tecomaria (Cape Honeysuckle)
Tecoma (Yellow & Orange Bells)
Passiflora (Passion Flower)
Senecio (Mexican Flame Vine-Let go deciduous, or won’t bloom next year)
Solanum (Potato Bush/Vine)
Cuphea (Mexican Heather)
Nerium (Oleander-saves the bloom)
Petunia (Saves the bloom)
Geranium (Saves the bloom)
Lobelia (Saves the bloom)
While you don’t want to prune frost sensitive or damaged plants now, January is the perfect time to prune deciduous trees and roses. Begin by pruning dead, cross-branching and diseased wood. Also thin trees and shrubs with a too-dense plant structure and scale back plants that are too large for their space. The purpose of pruning is to remove obstacles to healthy growth or to resize a tree/plant for the area in which it’s planted. We recommend you remove not more than one-third of the overall tree or plant when pruning.
Twigs and Small Branches
When pruning twigs and small branches, always cut back to a vigorous bud or an intersecting branch. When cutting back to a bud, choose a bud that is pointing in the direction you wish the new growth to take. Be sure not to leave a stub over the bud or cut too close to the bud.
Proper Pruning Angle
When cutting back to an intersecting (lateral) branch, choose a branch that forms an angle of no more than 45 degrees with the branch to be removed. Also, the branch that you cut back to should have a diameter at least half that of the branch to be removed. Make slanting cuts when removing limbs that grow upward; this prevents water from collecting in the cut and expedites healing.
Thick, Heavy Branches
Large branches should be removed flush with the collar at the base of the branch, not flush with the trunk. The collar is an area of tissue that contains a chemically protective zone. In the natural decay of a dead branch, when the decay advancing downward meets the internal protected zone, an area of very strong wood meets an area of very weak wood. The branch then falls away at this point, leaving a small zone of decayed wood within the collar. The decay is stopped in the collar. This is the natural shedding process when all goes according to nature’s plan. When the collar is removed, the protective zone is removed, causing a serious trunk wound. Wood-decay fungi can then easily infect the trunk. Even if the pruned branch is living, removal of the collar at the base still causes injury to the tree.
These techniques offer a great knowledge base for beginning your pruning maintenance. Other types of plants that can be pruned in January include: roses, deciduous fruit trees, grapes, and non-native deciduous shade trees.
Techniques for rose pruning almost approach a mystical cultism. Many rosearians and other avid rose enthusiasts swear by various methods that always pruduce the largest and most beautiful flowers imaginable. Following basic pruning principles and fertilization will always ensure your success.
For most roses, select three to five main canes that are evenly spaced around the crown to keep as the foundation for future branches and blooms. Thin out or remove the canes in the center of these, as well as any that may be weak or dead. Prune these main canes back one-half to one-third of their original size or about 12 to 18 inches in length.
When pruning, always prune above an outward facing bud. This will form a new branch and by choosing one that faces away from the center of the plant, you are able to keep the center of the plant open.
Climbing roses and miniatures need only to be pruned to shape.