LOCAL MASTER GARDENER KIMBERLY SEVILLA ANSWERS YOUR QUESTIONS.
Q: Help, I Have Spider Mites, What do I do?
When the weather warms up, plants tend to get dry, and those pesky spider mites come out to feast.
There are many types of spider mites but the ones that are a problem in our homes and gardens is the two-spotted mite (Tetranychus urticae). Spider mites are about the size of a grain of sand so they are difficult to see. The best way to tell if you have them is to examine the underside of leaves. Spider mites will leave small brown or yellow dots on the leaves, and sometimes fine strands of silk or webbing. Try holding a piece of white paper under a leaf and gently tap, if you see slow moving dots on the paper, these are most likely spider mites.
Female spider mites over-winter in soil or under bark. They emerge when the temperature warms up. In optimum conditions (over 80 degrees F. and dry), the life cycle of a spider mite shortens from a few weeks to a few days! Unchecked, a full on infestation can happen in as little as a week.
Spider mites can easily overtake and kill a plant, but fortunately for us, there are many ways to control them. Traditionally chemical controls have been used in commercial nurseries but recently spider mites have become resistant to those chemicals and because they kill insects that that eat spider mites they exacerbate the problem. Some commercial growers are now using biological controls such as predator mites, lady beetles and lacewings to keep spider mites in check.
There are pesticides available for the home user but more and more they don’t work, and are harmful to you and the environment.
You may not want to let loose a bunch of ladybugs in your house, so here are some ways that you can combat them indoors.
1. Isolate all infected plants and group them together to prevent the mites from spreading to other plants.
2. Remove any heavily infected leaves and discard any heavily infested plants.
3. Rinse off plants, especially the undersides of leaves, take your plant into the shower if you can or your kitchen sink, if you have outdoor space, use a hose with a sprayer, but don’t spray so hard that you damage the plant.
4. Make a solution of 1 part rubbing alcohol to 3 parts water, add a couple of drops of Dr. Bronner’s soap; tea tree or lavender is best. Spray the undersides of the leaves with this solution and rub off any visible webbing with your thumb.
5. Repeat this every few days until the infestation is gone.
Here is how to prevent an infestation in the first place.
1. Isolate any new plants, gifted plants or plants bought in from the outside for a few weeks just to make sure they are pest and disease free before mixing with your other plants.
2. Maintain proper humidity levels by keeping your plants properly watered and by using humidity trays, placing your plants on trays with rocks and water or by using a humidifier.
3. Be OK with spiders. Spiders eat spider mites and aphids and while they may bother you, they bother mites much, much more.
4. When weather permits, keep your plants outside; this is especially useful for citrus, fichus, gardenia, and jade plants which are particularly susceptible to mites.
Yes mites are pests, and yes they can kill plants but with proper precautions and care, they can be brought under control.
Q: I just moved into an apartment with a terrace. I would like to make it a bit more private, can you recommend plants that can stay outside all year?
With all the new construction, balconies and creative floor levels, having privacy outside is a common problem here in Brooklyn. We are literally on top of each other and no one likes being nose to knees with their neighbors.
Bamboo is an excellent barrier. It grows quickly and can be planted in planters and will create an instant screen. Be sure to choose one that is rated for zone 5 or lower and use the largest planter and plants that your budget permits. If your container is small, you may have to protect your bamboo over the winter with some insulation or some Christmas lights. Don’t worry if you have to start small, bamboo grows fast and will be at its prime in a year or two.
Choose a running type of bamboo that grows to about 12-15’ these will grow straight and tall and will look the best either in planters or in the ground. Clumping bamboo, while not as invasive as running, grows in a fountain or vase shape and may not be the best choice as it will arch over and take up too much space.
If you want to plant bamboo in the ground remember; bamboo spreads, a lot, and can easily overtake a small backyard. It is best to place it in planters or to use a rhizome barrier at least 18” deep. Thick PVC is best; metal flashing is dangerous and will rust over time. Plan on cutting out any escapees in the late spring as part of your yearly garden maintenance.
Q: Mosquitoes are eating us alive!
You finally have an outdoor space and you go outside at dusk to enjoy a summer evening after a long day at work, and then you discover one of the nasty secrets of Brooklyn. Mosquitoes, and lots of them!
We had an extra warm spring and those little pests got a head start this year. They are pretty bad here, bad enough to make me want to drive to Mexico and pick up a can of DDT. Short of importing banned chemicals, the best course of action though is to eliminate any standing water and prevent them from growing in the first place.
That being said, we can’t always control what our neighbors are doing; construction sites and abandoned lots are prime breeding grounds; even if you are diligent, your neighbors may not be.
If you don’t want to cover yourself with chemicals; plant lots of things that mosquitoes hate such as basil, mints, verbena, lemon grass, and scented geraniums (basically any lemon scented plants). You can also try some carnivorous plants. We put a few pots of venus flytraps and pitcher plants out last year and did notice a reduction in the population, it won’t eliminate the mosquitos but they are pretty to look at and a nice conversation piece.
You can try the natural sprays, I haven’t found them to be particularly effective though. Instead, try these things, use citronella candles and keep the air moving by using a fan. Wear light colored clothes and try to keep your arms and legs covered, think Laurence of Arabia, or poet shirts if you must. That will make your summer evenings much more enjoyable, more fragrant, and create an amusing fashion statement for your friends and family to enjoy.
I’d be happy to answer any gardening questions you may have. Please send them to: firstname.lastname@example.org
Kimberly Sevilla, Rose Red & Lavender
653 Metropolitan Ave
Williamsburg, NY 11211
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