While this has been an unusually hot September, this month’s heat does not eliminate the need to begin cleaning up the garden and getting ready for what’s just around the corner – October – Southern California’s best month for planting.
So get rid of fading flowers, spent annuals and vegetables that are no longer performing and hit the nurseries now to get the best selection of spring-flowering bulbs, some of which can be planted now, while others will be stored for future planting.
You also need to be on guard for our Santa Ana winds that can come roaring off the desert and down through the canyons, acting like a blowtorch on tress and shrubs. To help large perennials survive the stress caused by the winds, make sure that they are well watered in advance of the wind’s arrival.
Fall Tree Planting
This is the perfect time of year to plant a tree – the roots will get well established before they go dormant, ready for the spring surge of both foliage and root growth. But before you head for the tree farm, decide what you want from a tree – where it will be planted and for what purpose.
If you want summer shade for the house, a deciduous tree planted on the south side would be appropriate. If you prefer a pleasant window view, a grouping of silver birches might be nice.
Once you’ve made a preliminary choice, consider the mature size of the tree – does the area allow the tree sufficient space when it’s mature? Have you planned for the different needs of the shaded and moist soil underneath its widespread limbs? When all these considerations seem to fit, purchase it and plant it.
Store the bulbs you bought and didn’t plant in a cool, well-ventilated area until you’re ready to plant them. Chill crocus, daffodil, hyacinth, narcissus, and tulip bulbs in a paper bag on the lowest shelf in the refrigerator–at about 40 degrees–for at least six weeks. Wrap them in paper–not plastic–bag, since the bulbs are alive and must breathe.
Enrich the soil where the bulbs are to be planted with com-post, bone meal, and granite dust or wood ashes (but not from charcoal briquettes used in the barbecue, which contain harmful chemicals). Also, add some nitrogen, as it is easily washed from the soil by winter rains, and bulbs need a small but continuous supply all winter long for strong foliage and the bloom stalk growth.
For a long-lasting spring display, plant some early, mid-season, and late-blooming bulbs every other week from October through mid-December, and again beginning in late January.
Depth of planting also affects when the bulbs will bloom: shallower plantings will bloom sooner, and deeper plantings will bloom later. If you want everything to bloom for one spectacular display, plant the bulbs at the same time and at the same depth.
If you want to know more about what to do in the garden in September, check out Pat Welsh’s “Southern California Gardening – A Month-by-Month Guide, or Google, “Southern California Gardening September.”