Learn More About Growing Citrus & Bamboo

Learn more about growing citrus in your northeast Florida yard and about managing bamboo in your landscape.

Growing Backyard Citrus: Photo, Lemon Tree, Amelia Island, Florida
Growing Backyard Citrus: Lemon Tree, Amelia Island, Florida

Holiday Note:

A Landscape Matters class on Holiday Flower Arrangements is Tuesday December 8, 2015 at 10 am. The workshop will be held at the Yulee Extension office. The fee is $15 and must be received at either the Callahan office, or the Yulee Extension office by Dec 1. After Dec 1, the fee is $20. The fee covers the cost of supplies for making your own holiday flower arrangement. The registration form is available online.

Learn More About Growing Citrus in the New Year

Coming in early January 2016: On Jan 6th at 10 am, Nassau County Extension Director/Horticulture Agent Becky Jordi will conduct a Landscape Matters “Citrus Class”, at the Yulee Extension office (no registration is required). Learn more about citrus varieties for the home and citrus pest control. The class is free and open to the public. For additional information see the Nassau County Extension website or call the office at 904-530-6350.

Garden Talk Q & A

University of Florida/IFAS Extension Director for Nassau County and Environmental Horticulture Agent IV, Rebecca Jordi answers questions about landscaping and gardening in northeast Florida.

QUESTION: What is this white powdery stuff on the trunk of my citrus tree? LJ

Snow Scale (Photo by University of Florida Entomology Dept.)
Snow Scale (Photo by University of Florida Entomology Dept.)
JORDI: This pest is called citrus snow scale and believe it or not – it is an insect.

Citrus snow scale attaches to the trunk and sometimes when populations are extremely high, it can be found on leaves and other parts of the citrus tree. The insect feeds on the plant juices diminishing the nutrients available to the tree. The insect reproduces in large numbers to cover the trunk tissue where it resembles “snow.” Armored scales are distinguishable from soft scales by the removable cover or ‘armor’. As crawlers, the females of snow scale insert their long mouth parts into suitable hosts and never move again. The immature males become immobile once they begin feeding and remain immobile until they emerge as winged adults. In severe infestations, the bark of the trunk or limb can split, making the tree vulnerable to fungal disease.

Citrus snow scale has a tendency to pile up on top of one another making chemical application difficult to reach the bottom layer. Consider brushing the stems and branches with a soft toothbrush or larger soft brush first to remove some of the layers of the scale. Then apply insecticidal soap or all season horticulture oil. More than one application will be required.

QUESTION: My neighbor’s bamboo is becoming a problem for my property. What can I do to keep it under control? JH

JORDI: You will only be able to manage those reeds popping up on your property if you have your neighbor’s permission. If you are having a problem, then your neighbor might be frustrated too. Working together would be ideal.

Arundinaria Gigantea (Photo by Shirley Denton)
Arundinaria Gigantea (Photo by Shirley Denton)
It may be hard to believe but bamboo is really just a giant type of perennial grass. Most people use it as a hedge for privacy or keep it in large planters to enhance a patio.

There are numerous varieties of bamboo ranging in heights from 1 to 70 feet tall. The United States has only one native species, called cane or canebrake bamboo. This native bamboo generally behaves itself and does not become a nuisance in our wildlife areas or our neighbor’s yards.

However, there are dozens of imported bamboos which are highly invasive and exceedingly difficult to control. These invasive varieties have large underground rhizomes used to store food for the plant. Non-native bamboo is extremely difficult to control as it requires killing all the rhizomes. Bamboo plants typically build extensive rhizome networks underground. This makes management of bamboo intensive and difficult because all it takes is one rhizome cluster and the bamboo will return.

You can try mowing the canes a couple of times a week, similar to lawn grass, and this will reduce the amount of chlorophyll available to produce food. Regarding any chemical applications, we would recommend using glyphosate in the form of a 5% solution or 6 ounces per gallon. The University of Florida recommends using glyphosate with a 41% concentration of the active ingredient. While some studies have shown the active ingredient imazapyr is more effective on bamboo than glyphosate, this product can leach into the soil and damage surrounding plants such as trees, shrubs and other perennials. Therefore, we would not recommend applying this product to the bamboo on your property. Unfortunately, it will most likely take between three and four applications of glyphosate to control this pest.

This is an important message for us when adding plants from other countries to our landscapes. If you do not want to use chemicals, you can put a barrier between the bamboo and your property. Dig a trench approximately 36 inches deep. Use rolls of fiberglass or 60 mil polypropylene in the trench. Leave about 2 inches of the barrier above the soil to discourage rhizomes from growing over the top of the barriers. It sounds extreme, but it does work.

QUESTION: When do I prune bamboo? JD

JORDI: No matter what time of year, you can prune out dead canes. That rule also applies to any tree or shrub. Some people like a dense thicket while others like a more open and airy look. Generally, we recommend taking out any canes over seven years old. You can use a pruning saw, just be sure it is sharp and cut the cane at ground level. Prune bamboo most any time of year except when it is producing new shoots as it would be easy to damage the new growth.

Rebecca Jordi
Rebecca Jordi
Rebecca L. Jordi
Nassau County Extension Director
UF/IFAS Environmental Horticulture
543350 U.S. Highway #1
Callahan, FL 32011
904-530-6350
http://nassau.ifas.ufl.edu