Thursday, May 24, 2018
Home and Garden

How to get rid of scales on Zamia, thrips on gardenias

Identify that Zamia and its scale first

Q: Will neem oil work in controlling scale on cycads? Our Zamia is totally covered. Is there a better way to control the scale?

Sandy Vargo

A: Neem oil works in controlling scale quite well. However, the size and concentration of the infestation along with the positive identification of the insect and plant need to be taken into consideration when developing a control strategy.

Florida red scale — an armored scale that looks like a pimple, black with a reddish top that doesn't move as an adult — and mealybugs — small ⅛-inch greyish-yellow critters covered with white powdery wax, which are mobile about the leaf — are Zamia's two primary scales.

If your problem plant is Zamia integrifolia (floridana), our native coontie, cut the foliage down to the ground and let them start over. It sounds drastic, but it's your only recourse. Then continue to monitor the new foliage for any scale. The more shade they are in, the worse scale problems can become.

If your problem plant is Zamia furfuracea, cardboard plant, remove the most infected fronds and spray on 10- to 14-day cycles with neem oil, following label directions, until the problem is under control, then monitor and act quickly if the tiny rascals return.

Spray those thrips, but flowers may become damaged

Q: We have a gardenia bush and when it flowers, there are little black bugs all over the flowers. What are they, and how do we get rid of them? Earl Little, New Port Richey

A: The pesky little critters in and on your gardenia flowers are called thrips. The tiny black ⅛-inch insects feed by rasping plant parts, flowers in your case, then lapping up the plant sap. This type of feeding causes flowers to shatter, lessening their useful life. For control, there are many products that contain synthetic pyrethroids as an active ingredient and all end in "thrin": bifenthrin, cyfluthrin, lambda cyhalothrin, permethrin, etc. Some of the brand names include: Ortho Bug-B-Gon Max, Bayer Advanced Rose & Flower, Bayer Advanced Garden Power Force, Spectracide Trazicide Once & Done, Spectracide Immunox Plus, Southern Ag Permetrol Rose Flower, Fruit & Vegetables and many more. Some are concentrates and others are ready-to-use. Spray, according to label directions every seven to 10 days. Oil sprays damage the flowers.

Never fear: That corkiness is normal in adolescence

Q: This is our sweetgum. It is just now leafing and has this funky growth. Can you tell me if I need to administer first aid? We love this tree and would not want to lose it. Linda Baker

A: Not to worry, no Band-Aid or surgery will be needed. Both sweetgum, Liquidambar styraciflua, and winged elm, Ulmus alata, put out corky projections on their twigs and stems as part of their bark. The fluting on sweetgum doesn't usually appear for the first few years, so when it appears, it looks a tad scary. On the other hand, winged elm, by its name, gives the new owner a heads-up. As your sweetgum ages, it will lose this juvenile characteristic, but the elm is corky for life.

Here's how to root a cutting

Q: I recently obtained a kapok blossom and it was on a piece of tree branch about 6 inches long. I put the branch in a small amount of water outside. This was about two weeks ago. The branch has 2 green sprouts now growing out of the part that is not in the water. There are no roots showing on the bottom of the branch in the water. I would really like to grow this into a tree. What should I do next? Can I put it in a pot in potting soil without roots? I hope you have an answer. Donald Wiley

A: The easiest way to root a cutting is to take a 1 gallon plastic bag, fill it ⅓ full with a moistened (not wet) peat-based mix such as FoxFarm Light Warrior Soiless Mix, Hoffman All Purpose Potting Mix, Fafard, Promix, Jiffymix or Miracle Gro Potting Mix; make a fresh cut at the bottom of the stem (with sharp clippers); apply a rooting enhancer such as Rootone, Hormex, Clonex, Hormodin or Dip-N-Grow on the end of your cutting; place into the bagged moistened peat mix approximately 2 inches deep; close the bag ¾ of the way; and place in bright light. Check periodically for any heat buildup, and move accordingly. In four to six weeks you should have sufficient roots to upgrade.

Pot it into a 4- to 6-inch container with some of the same mix to grow on. You can use your mini greenhouse to root just about any plant with stems, 4- to 6-inch cuttings of "green wood" (new spring growth) forms roots the quickest.