During the cooler winter months, you may notice the leaves of your citrus trees looking a bit pallid. This could be an indicator of a lack of nutrients or overwatering. Check the soil around the base of the trunk to ensure that it is slightly damp and spongy, not soggy. If the soil is too wet, reduce the number of emitters on the drip irrigation around the plant. Yellowing of the leaves may also mean that your citrus isn’t getting enough nutrients from the soil. Remedy this by using a liquid iron fertilizer and by placing grass clippings or mulch near the trunk. As the grass decomposes, vital nutrients will break down into the soil and be taken up by the roots of your tree.
Roses and fruit trees go dormant in the winter, making it the best time of year to prune. Plant structure is most obvious when there are no leaves, and you can easily identify branches that are growing in toward the canopy, crossing branches, and diseased or dead wood that need to be removed. Creating space between branches is important, as it allows for air circulation and keeps moisture from becoming trapped and encouraging fungal growth on tender leaves in the spring.
Winter is also prime time to prune the tips of fruit tree branches to keep the tree at a manageable height. Doing this keeps fruit within reach without the need for a ladder when the time comes to harvest. When pruning, make sure to cut at a slight angle just above an outward-facing bud.
Remember, in addition to being important for plant health, pruning also invigorates your plants, making it the surest way to get fantastic blooms in the spring and delicious fruit in the summer!
Fungus can take up residence on your plants during the growing months, but you can combat it effectively during the winter. Be sure to clear fallen leaves from plants that are particularly sensitive to fungus, such as roses and fruit trees. This will help prevent the fungal spores from spreading to new growth in the spring. After all leaves have fallen from the plant and you have pruned, spray a combination of copper fungicide and horticultural oil to lightly (but thoroughly) coat the branches. Once the mixture has dried, it will guard your plants against harmful fungus and other pathogens.
When outside temperatures drop, you’ll want to check your garden for plants that need to be protected from frost. Many plants, including citrus, succulents, and other tender perennials are susceptible to damage when temperatures drop below freezing. To avoid dieback, prop frost blankets up on stakes or tomato cages around sensitive plants, making sure not to weigh them down. This will allow the plants to breathe even while covered, and keep branches from breaking under the weight of the blanket. Avoid using burlap or plastic tarps for this job, as they will not keep plants as warm as a frost blanket. If all you have are old sheets, use several layers on each plant to provide enough coverage. Frosts are few and far between during our coastal winters, but when they do come, your plants will thank you for taking the time to cover them!