Infection typically begins at the centers of the flowers and moves outward. Infected flowers usually disintegrate as their interiors turn to mush, often before infection becomes visible on the outside. Sometimes, flowers instead remain intact as they turn brown and fall to the ground.

Sasanqua camellias with profuse, small flowers are not quite as sensitive as the more common camellias, Camellia japonica, because they bloom while weather is warmer and therefore probably drier. Also, their flowers have fewer petals, so their interiors can dry out better. White and pale pink flowers of both types are more susceptible than bright pink or red flowers.

Sanitation is the best defense against camellia petal blight. Rotting flowers should be removed from the plant or raked from the ground. They should be disposed of or buried, but not put into compost. Otherwise, spores of the blight will simply lie dormant as they wait for their compost to eventually be dispersed back into the garden. Spores that are already in the soil below camellia plants can be partially suppressed by mulch that is about four inches deep. Because the mulch will collect spores from above, it should be replaced annually, preferably just before bloom.

Camellias often produce more flower buds than they can sustain, so it is normal for a few to fall without opening. Many camellia hobbyists actually prefer to "cull" (remove) inferior buds as they are developing, to conserve resources for the buds that are left to bloom. However, excessive watering may increase bud drop enough to diminish bloom. Under-watered young plants may react similarly. Buds that dry without falling off should be removed and disposed of like blighted blossoms because they may be infected with a similar fungal disease.

Densely overgrown camellias do not seem to mind getting pruned at any time, but ideally should be pruned immediately after bloom. Pruning to thin congestion during autumn or winter would of course diminish bloom, and can promote new growth late when it would be sensitive to frost. Similar pruning as bloom finishes removes much of the expanding vegetative (bloomless) shoots behind the fading flowers, but promotes more vigorous and less congested new growth, which will be mature enough to survive frost and bloom by next winter.

Houseplant of the Week:
spider plant

Unlike the itsy bitsy spider, the itsy bitsy spider plant, Chlorophytum comosum, will not go up the waterspout. However, it does have a sneaky way of getting around sheltered areas of the garden. It produces abundant spider-like offsets on long, limber stems. These offsets root and grow rapidly wherever the stems set them down. They then produce even more offsets, eventually forming a rather shaggy groundcover about a foot deep. Those that get into exposed areas either freeze in winter or yellow in direct summer sunshine.

Spider plants are most often grown as hanging houseplants, with their offsets hanging downward. Even without rooting into the ground, hanging offsets can produce their own offsets, which can do the same, until the lowest are a few feet below the top parent plant. Small white flowers often bloom among all the foliage. The softly arching grassy leaves typically have white margins or centers, or both. Less common unvariegated spider plants with slightly stiffer lime green leaves might produce fewer offsets.

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