Tips for container gardening in California

by Nan Sterman

One great thing about container gardening in most of California is not worrying about winter. In all but the state's coldest climates, containers don't have to be moved into garages, basements or greenhouses to protect them from the cold. Temperatures never dip low enough to shatter ceramic pots or heave plants from their containers.

Instead, we can focus on container gardening year-round. Here are some ideas for planting containers this time of year.

If you like natives, this is the perfect time of year to plant. Not all natives tolerate a long-term stint in a container, but many do. Hummingbird sage (Salvia spathacea) grows low and wide with deep magenta flowers and broad, ruffled green leaves that smell fruity when crushed. Combine them in a container with native bunch grass such as a blue or green-bladed Festuca idahoensis or the much larger blue-leaved, giant wild rye, Leymus condensatus "Canyon Prince."

Native, succulent Dudleya perform well in containers filled with a fast-draining cactus and succulent mix. Dudleya edulis (the San Diego Dudleya) has narrow, chalk-green leaves. Dudleya brittonii (Britton's chalk Dudleya) has broad, flat, blue-green blades and absolutely fantastic blooms. Plant them singly and use to decorate your patio table.

Don't be afraid to mix woody plants with succulents, perennials and herbs. Start with large containers, at least 20 inches tall and wide. Use a high quality, well-draining potting mix. To play it safe, mix construction sand into the potting soil, to equal 30 percent of the total volume.

For the container's centerpiece, try a smaller Australian Melaleuca, such as Melaleuca filifolia. This 4- to 6-foot plant sports small, mauve puff flowers in winter and spring. Melaleuca hypericifolia has coral colored bottlebrush flowers in spring and summer. It grows 6- to 12-feet tall in the ground. Woody plants tend to stay smaller when grown in a container.

Underplant Melaleuca with a dwarf New Zealand flax, such as the 2-foot-tall, green and cream variegated "Tiny Tiger." As a filler, ornamental oregano such as "Bette Rollins" does great. The oregano's round, green leaves will form a mat over the surface of the container, then spill over the sides.

Culinary bay (Laurus nobilis) is great in a container and will stay considerably smaller than the 20 feet it reaches in the ground. I particularly like tall, columnar containers to echo bay's tall, columnar shape.

Before you plant any container, make sure it has at least one large drainage hole in the bottom. Cover the hole with a square of fiberglass window screen to keep the potting mix from washing out the bottom.

Big containers are heavy once planted. So, put the container where you want it, then plant. Add a few handfuls of worm castings, compost or other organic matter to the potting mix and moisten thoroughly before filling the container.

Set plants so they sit at the same level in the container as they did in their nursery cans. Don't skimp on potting mix. Fill to within an inch of a container's rim. The mix will settle a bit over time.

After you finish planting, top the potting mix in an inch of rounded gravel mulch. The gravel keeps the potting soil moist between waterings, keeps dirt from washing out when you water, and gives the container a nicely finished look.

Nan Sterman is the author of "California Gardener's Guide Volume II." She's a gardening expert, communicator and designer who has long grown an organic garden that both feeds her family and beautifies her yard.