The garden is so cold and muddy that I was not motivated to go outside to get out of the way inside. In fact, the only advantage to doing this project in winter is that the houseplants from the dining room enjoyed temporary relocation into the garden. I actually took plants from other rooms out to enjoy the rain as well.

Even prior to the beginning of this project, houseplants that had been inside for a long time had accumulated dust on their foliage. The warm, dry (minimal humidity) and dusty foliar environment has been ideal for spider mites and scale insects to proliferate, uninhibited by natural predators among some of the palms. Rainstorms that last a few hours rinse off more of this dust and dislodge more of the infesting pests than brief rinsing by hose would.

If infested, houseplants can stay outside long enough, ecology takes over and predatory insects diminish the populations of detrimental insects and mites. Ecology unfortunately also dictates that snails and slugs, which are slower but still active during winter, may find houseplants to be appetizing.

Winter is the best time to put houseplants out in the rain because it is the only time of year that it rains here and because houseplants are not as easily burned by exposure to sunlight as they would be during summer. However, winter weather is not perfect either. Houseplants are not exposed to windy or cold weather in any residence equipped with a roof, so may be damaged by frost or wind if too exposed in the garden. They should be placed in areas that are open to rainfall, but are protected from wind. Because protection of such sensitive plants from frost is so involved, houseplants should be moved back into the house or at least a garage prior to frost. Fortunately, rainy weather is rarely detrimentally cold.

Direct sun exposure is not as damaging during shorter and dimmer days of winter as it is during summer, but can potentially damage foliage that is adapted to shade within the home. Just as weather is typically not rainy and very cold at the same time, rainy weather is innately not sunny. However, weather can quickly become clear and sunny after a storm. It is therefore best to bring houseplants inside after a storm unless they will be shaded if the sun comes out.

It would be convenient to perform any repotting or "stuffing" while houseplants are outside. Stuffing is done to houseplants that are so rarely repotted that their potting soil decomposes and collapses. The root ball is removed from the pot so that more potting soil can be put below the root ball, which is then placed back in the pot with more potting soil to fill the wider taper higher in the pot. Soil should only be placed over the root system to cover exposed roots, but should not be so deep that it promotes rot.

Flower of the Week:
Artichoke

In the Santa Clara Valley, artichokes can be harvested in late spring or early summer, but they should be planted in a sunny area about now in early winter or as late as spring. Dormant shoots become available with some of the first of the bare root plants, such as the various berries. Mature specimens may likewise be divided about now.

Whether divided or not, artichokes are dormant during late winter, so their yellowing foliage should be cut back before new foliage emerges from the perennial shoots in spring. New foliage will later be susceptible to aphid infestation, but will be resilient enough to tolerate a strong spray of water to dislodge the aphids. Foliage is unfortunately not so resilient to slugs and snails, which may necessitate baiting.

Even those who do not enjoy artichokes as a vegetable may appreciate the bold foliage and bloom. Mature specimens may be as high as four feet and as wide as six feet, and are comprised of coarse grayish green foliage that arches outward from the central shoots. Artichokes emerge from these same central shoots as floral buds atop vertical stalks and may be harvested while somewhat small and tender, or left to bloom as bulky five-inch wide thistles with purple-blue centers.

Horticulturist Tony Tomeo can be contacted at 408.358.2574 or at LGHORTICULTURE@aol.com.