Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: We have been having an issue with our Ficus benjamina for several months. It has been getting increasingly worse. It has mealy bugs. They are on the leaves and branches.
MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your question about treating mealybugs on your Ficus benjamina. We will answer the question assuming you've already been given a correct positive identification of mealybug. If you are not 100% sure what the insect is, please consider sending us a close up photo or bringing in a sample for us to use for a positive ID.
As you may already be aware, mealybugs are small, pale insects, related to scales. They are about ⅛ to ¼ inch long and move very sluggishly. The adult females cover themselves and their eggs with a white, waxy material, making them look cottony. Mealybugs are most commonly found on the lower surfaces of leaves and in leaf ails (where the leaf attaches to the stem). They suck plant sap, causing stunted and distorted growth and sometimes plant death.
Mealybugs are difficult to control with insecticides because they have a waxy coat that protects them. On houseplants, (as you have already been guided to try), insecticidal soap, narrow-range oil, or a forceful stream of water can be applied to reduce exposed populations. You can also dip a cotton swab in rubbing alcohol and place it directly onto individual mealybugs to kill them.
Here are links to more information and treatment recommendations (including insecticide options) for mealybug:
http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/INVERT/mealybugs.html
http://ipm.ucanr.edu/PMG/PESTNOTES/pn74174.html
http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/ficus.html
Care of Houseplants
The best way to control insects and related pests on houseplants such as your Ficus benjamina is through prevention, as it is almost always easier to prevent a pest infestation than to eliminate one. There are several precautions that you can take which will decrease the chances of having to deal with a pest infestation of your houseplants:
- Provide a plant with the growing conditions that it needs so that it is more likely to grow vigorously. Stressed plants tend to be more susceptible to pests.
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Before buying or bringing a plant indoors, always check it and its container for signs of pests. (We have found mealybugs on many plants for sale in various stores so buyer beware!)
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Isolate new plants from plants already in the home for six weeks to ensure that any pest brought in will be less likely to spread.
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While plants are isolated, carefully examine them for signs of pests or damage on a regular basis of about once a week. Pay particular attention to the undersides of leaves where pests are most often found. Infestations are often much easier to control if caught early.
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When repotting a plant, use commercially prepared potting soil rather than soil from outdoors, which can be a source of pests.
- Washing smooth-leaved plants every two to three weeks discourages pest infestations and also improves the appearance of foliage. Small plants can be inverted and swished in a bucket of tepid (lukewarm) water. To prevent loss of soil, cover it with aluminum foil or plastic wrap. Large plants can be hosed down gently, or upper and lower surfaces of leaves can be wiped with a soft, wet cloth. Large plants can also be rinsed in a tepid shower.
Good luck with your tree! We wish we could offer happier news. Please let us know if you have additional questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (SLH)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer our gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523, although we will be moving this spring. We will notify you if/when that occurs. We can also be reached via telephone: (925)646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/)
/table>Advice from the Help Desk of the UC Master Gardeners of Contra Costa County
Client's Questions: My daughter has a Peace Plant that has not been re-potted for about ten years, the soil is about 5 inches below the top of the pot, and the stems are about 6 inches long. I am thinking that if I add soil (about 2 inches at a time) to the pot that the stems will develop roots and then can be divided and re-potted. Or if I divide it and re pot with soil at the same level how will I get rid of the stems? Or will the plant start new shoots at the soil level and then I can cut off the old stems? What do I need to do to re-pot it?
The first thing to do is to water the plant the day before you want to repot. This allows the roots to hydrate and swell so they won't dry out during the repotting process. It also helps the soil release from the roots when you take it out of its pot. Resist the urge to add soil to the existing pot--this can lead to the stems rotting.
To remove the plant, hold the pot upside down with your hand supporting the root ball as it slides out. If it doesn't readily come out, gently tap the pot with your hand. Place the plant on its side, taking care not to damage the leaves and stems. Inspect the plant to determine how many divisions you can make. Each one should have at least 3 stems/leaves. Grasp the stem of each division and gently work the roots free. Alternately, you can use a sharp knife to cut the root ball, but make sure each section has enough intact roots to support the new plant.
Using a quality potting soil, fill the new pots about 1/2 full and position the section in the pot so the new soil will hit the plant at the same level it is now. Add more soil around the roots, aiming to eliminate any air pockets. You don't want to bury the plant any deeper than it is now. Firm the soil with your hands. Then water until water runs out the bottom. Place the new plants in similar lighting as the original. Guard against over-watering in the beginning until new roots are able to take up water. Always test the soil before you water--if the soil is still damp 1/2" down, you don't need to water. Peace Plants are more likely to die of over-watering than under-watering.
Good luck with your Peace Plant!
Help Desk of the UC Master Gardeners of Contra Costa County (SEH)
Editor's Note: Fun Fact -- the Peace Lily is one of the house plants that NASA found help keep indoor air quality "clean". http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930073077.pdf
Note: The UC Master Gardeners of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/blogcore/blogroll.cfm).