We have a 40 year old camellia that has lately been invaded by spider mites. All of its leaves have turned brown on the front side, while the backside is still very healthy looking. Can you recommend a solution which would save this otherwise beautiful plant?
Hans Schurig, Hollywood
Spider mites are particularly nefarious pests on account of their rapid rate of reproduction, developing from egg to adult in one week during warm weather. Spider mites, which happen to have eight legs at maturity, are not insects, which are six-legged creatures. Instead, spider mites are in the same class as ticks, spiders, and scorpions. However, the damage inflicted by spider mites is similar to that of the sucking insect “Big 5”, those being aphids, thrips, mealybugs, whiteflies, and scales. In the manner of these insects, spider mites simply insert needle like stylets into leaves and siphon sap. You will need a magnifying glass to zero in on a mite since they are between 1/50th and 1/20th of an inch in size, about as big as the period at the end of this sentence. Leaf stippling — a sandblasted look — is the most common symptom of mite infestation, with webbing sometimes present. They are commonly found on indoor plants, although their appearance on vegetable and strawberry plants and on garden ornamentals such as roses, conifers, and boxwoods is not unusual.
While there are many species of pestiferous mites, the strategy for controlling them is always the same. For mild infestations, strong blasts from a hose can be effective in limiting the spread of spider mites. Otherwise, as in the case of your camellia, it is best to use petroleum based horticultural oils, botanical oils such as neem or Mite-X, or insecticidal soaps in their control. Mite-X is made from cottonseed oil, clove oil, and garlic extract. Back in September, I recommended the use of chili peppers in spider mite control. Hot Pepper Wax is available as a spray or you can make your own solution by mixing 2 tablespoons of Tabasco sauce and six drops of dish washing soap into a gallon of water. Fill a spray bottle with this homemade brew and you’re ready to go, whether the pest in question is spider mites of one of the “Big 5” insects mentioned above.
Using inorganic chemical sprays, as opposed to oils and soaps, can be counter-productive since natural predators, especial species of predatory mites, will be killed in the process. Other mite predators, including lady beetles, six-spotted thrips, minute pirate bugs, big-eyed bugs and lacewings, will also die from chemical applications.
The best strategy is to spray one of the oil or soap or chili pepper preparations mentioned above, after which you release predatory mites for long term control. While the spray will bring down the population of damaging mites, it will leave enough of them in place to provide prey for predatory mites which, even as they munch on pest mites, do not, themselves, suck sap from plants. Rincon-Vitova Insectaries, in Ventura, grow five species of predatory mites. They can be reached at 800-248-2847 or go to rinconvitova.com to learn more about predatory mites and to introduce yourself to the full spectrum of beneficial insect options for control of those “Big 5” sucking insects (see above), too.
Mites are attracted to dust and congested growth so the best means of prevention is to keep foliage hosed down and dust free on plants known for being attractive to mites, and then keep these plants pruned out so air can freely circulate through them.
I taught my 6th grade science class about George Washington Carver’s success with peanuts for making soil fertile again. They could not understand the concept about the nodules on the roots of the peanut plant containing nitrogen-fixing bacteria. I thought I would grow a plant to show them. However, while researching on the internet I got the impression that California will not allow peanut plants here. I asked at Lowe’s and they said they did not carry the plants nor the seeds. Is it possible to grow peanuts here?
Cathy Cushman, Upland
You can definitely grow peanuts here. Peanuts, like peas, are the seeds of a leguminous plant and grow in pods. The key is to use raw, unroasted peanuts which you can order online or find in ethnic food stores or occasionally in supermarkets. If you do an online search for “peanut seeds,” you will find them available for around $3 a pound. You will want to make sure you keep your peanuts in the shell until planting since, once out of the shell, peanuts quickly lose moisture. Also, keep the papery red skins around your peanuts when you place them in the soil, no more than one inch deep.
As for growing them, you will need fast-draining soil and full sun. If you search “how to grow peanuts” you will find plenty of information on the subject, including videos. You can grow peanuts indoors in a sun room or very well lit location since they do require good light all day long. Pots should be five inches deep and soil should be sandy. Products sold by the bag as “Topsoil” are typically rich in sand and should make an excellent medium for growing peanuts. Keep in mind that the plants are slow growers, taking a good 6 months to mature, and so, if you plant now, you will have to wait until July, at the earliest, before you can harvest them. At harvest, pull each plant in its entirety out of the ground. Each individual plant produces up to 50 or more underground pods. These pods are not connected to roots, however, having developed from flowers above ground that send filaments, known as pegs, into the soil. From these pegs, peanut pods develop.
In the early 20th century, alongside citrus and walnuts, peanuts were a major crop in Orange County. In 1901, it was recorded that 12,000 sacks of peanuts weighing 40 pounds each were harvested on farms in an area comprising Orange, Tustin, and Santa Ana.
Tip of the Week: One of the most carefree perennial winter bloomers is Australian fuchsia or winter bells (Correa spp.). Australian fuchsia flowers are flared tubes of white, red, or pink. This plant can be grown under the same conditions as California natives and it is generally frost hardy. Correa pulchella ‘Pink Eye’ is a favorite selection. For best results, acidify soil with gypsum prior to planting and apply gypsum twice a year as a topical amendment on the soil surface.