What to do in your Southern California garden in December
Continue planting low- water, Mediterranean-climate plants, including coast rosemary (Westringia fruticosa), grevillea, Jerusalem sage (Phlomis frutictosa), lavender, lion’s tail (Leonotis leonurus), rockrose (Cistus), and rosemary (Rosmarinus officinalis).
Add natives such as California currant (Ribes), California wild lilac (Ceanothus), live oak (Quercus agrifolia and Q. berberidifolia), and manzanita (Arctostaphylos) to your garden.
Set out bare-root fruit trees. In areas with the mildest winters, choose low-chill varieties. For apples, we like ‘Beverly Hills’ (near the coast), ‘Winter Banana’, or ‘Winter Pearmain’. For pears, our picks are ‘Monterrey’ or ‘Kieffer’ (an Asian pear hybrid).
Sow seeds of root vegetables, including beet, carrot, rutabaga, and turnip.
Water only if Santa Ana winds blow or if more than two weeks pass without rain. Make sure that the soil is dry before turning on irrigation.
Clip off dead brown branches that have accumulated beneath the healthy green growth on perennials and shrubs.
Before winter storms do too much damage, prune pines, oaks, and other deciduous trees of weak or cracked limbs, and open up the canopies so wind can pass through them. If the trees are big, hire a certified arborist to help; find one at isa-arbor.com.
Move frost-sensitive pot- ted plants to a sheltered spot in a courtyard or under eaves.
If plants get hit by frost, resist the urge to prune away injured tissue. The damaged parts will protect inner growth from additional harm should there be an- other frost. (Once spring growth appears, you can cut off dam- aged areas above it.)
Insulate frost-sensitive plants with floating row cover, which can raise the temperature inside the “tunnel” a few degrees while keeping out birds and pests. Use flexible PVC pipe to bend arches over edible crops in raised beds or in the ground, then drape the arches with row cover. It’s available at farm and garden stores, or online from groworganic.com.