Q: I live in a town house complex that is going to be fumigated (tented) next month. I have many valuable house plants that will have to be taken out for three days. Will they survive if left outdoors? What can I do to best ensure their survival? Would they survive in a dark enclosure with no light?
– Ben Levin, Lake Balboa
A: Most house plants are much tougher than people think. If you soak your plants well and then place them outdoors in the shade, they should be fine for three days. You can also put them in the garage for three days without worry unless that structure, too, is being fumigated.
After soaking them, you could also put your plants in buckets with a few inches of water in the bottom to provide an extra measure of emergency fluid. As for your foundation plants and hedges – those next to the outside walls of the town house complex – make sure that the outside of the fumigating tent does not cover them. Nearly all plants die after exposure to fumigant chemicals.
Interestingly, the trunk of a car is a remarkably cool place and, in an emergency, plants can be left there for two or three days without ill effects. However, under no circumstances should you leave them inside the passenger area where, with sun streaming through the windows, your plants will quickly wilt or “cook” as a result of the accumulated heat.
One way of ensuring health of potted plants that are left unattended for an extended period, whether due to fumigation or vacation, is to double pot them. You do this by finding containers one or two sizes larger than the ones that contain your plants. Nest each smaller container inside its larger counterpart and fill the space between them with moist peat moss. The wet peat moss will buffer the temperature and conserve the moisture of the soil of the potted plants.
The bacterial leaf scorch epiphytotic, a plant epidemic among oleanders, continues. This is a hit-and-miss disease without any known cure. After an oleander is affected with this malady, it eventually dies. The bacterial pest is carried in the saliva of a leafhopper, which, as it sucks sap from a plant, injects bacteria into it. Sick plants transmit the bacteria to leafhoppers that alight upon them.
I have noticed that regularly sheared oleanders appear to be less affected than oleanders that are cut back only occasionally. It could be that pruning, which is an invigorating procedure and changes the hormonal balance in a plant, could stimulate the synthesis of certain bio-chemicals that help oleanders fight the bacteria.
Phytophthora is the most common soil-borne, plant-invading fungus, yet it is not found in virgin soil. Phytophthora is introduced into an orchard or a landscape through nursery plants, or carried on the soles of shoes, or transferred in the dirt that sticks to a shovel.
If you see the shoot tips of azalea, escallonia, California lilac (Ceanothus), or hopseed bush (Dodonaea) turning brown or shriveling, the culprit is Phytophthora. The sudden death syndrome of oak trees and the early demise of avocado trees are caused by Phytophthora. If you plant annual, warm weather vinca and suddenly see your plants begin to die, this same fungus pest is to blame.
It has been shown that a thick layer of woody mulch deters Phytophthora. Apparently, the same beneficial decomposing bacteria that proliferate on account of the wood fiber in the mulch hang around to make dessert out of Phytophthora cell walls.
TIP OF THE WEEK: When mulching, make sure to leave a mulch-free circle around all plants. You do not want to keep root fungus out of your garden only to see your plants succumb to trunk or stem rot because their surfaces could not dry out.