Garden Talk

with Rebecca Jordi


Leave a comment

Q: I need some ideas on plants rabbits won’t eat.

Marsh RabbitA:  Unfortunately, if the animal is hungry enough they will eat most anything. They particularly like vegetable garden plants and most anything in the rose family which includes many of our fruit trees. However, there are a few plants rabbits seem to avoid such as agaves, aloes, Gaillardia spp., cucumber, shrimp plants, euphorbias, plumbago, rosemary, squash, verbena or yucca.  Now, I know someone will call me and tell me they know one of those plants listed was eaten by a rabbit, but remember, if the rabbits are hungry enough anything edible is susceptible. You can use one of the repellents which may help reduce or prevent rabbit damage. These products work by creating an unpleasant odor, taste, or stickiness.

 Apply repellents before damage occurs, and reapply them frequently, especially after a rain, heavy dew, or sprinkler irrigation or when new growth occurs. In all cases, follow the label directions for the repellent.

 The usefulness of repellents is limited. Most, except for some of the taste repellents, can’t be used on plants or plant parts humans eat. Repellents often fail when used in a vegetable garden even if the repellents are registered for use on edible crops. The story of Peter Rabbit should be a warning to us; rabbits will get into a garden – it is just too tempting. 


Leave a comment

Q: The buds of my hibiscus are turning yellow and dropping off. What is wrong?

Hibiscus bud midge maggot

Hibiscus bud midge maggot

A:  After opening one of the yellowing buds we discovered the hibiscus bud midge maggot, Contarinia maculipennis.  The female midge deposits eggs on the tips of the newly forming buds and within 24 hours the maggot develops and starts to feed on the bud.  It takes about one week for the insect to mature to the next stage; then they drop to the ground to pupate. The soil must be moist, which is generally not a problem in our landscapes.  It will take about 2 -3 weeks to mature into an adult. The adult midge is very small – similar to a mosquito. Although hibiscus is the favorite, the bud midge has been known to also infest tomatoes, jasmine, plumeria, other vegetables and ornamentals. There are other reasons for flower buds to turn yellow and drop off such as over watering, too much nitrogen, thrips or aphids, and very hot, dry weather.  However, since I found the maggot, I am going to blame it on the bud midge.  The best thing for homeowners to do is to be sure to clean up any buds and leaf litter which have dropped to the ground.  If the hibiscus plants are in the ground they may not need supplemental watering aside from what we get with rain.  Remember, the midge requires moist soil to pupate.  Contact chemical sprays don’t work well since they cannot penetrate the bud.


Leave a comment

Q: What is the name of the insect and what does it do? It looks like it has a long stinger at the end of the abdomen.

Broadnecked Root Borer

Broadnecked Root Borer

A: I believe the insect you brought in to the office is a Broad-neck root borer, possibly Prionus laticollis.  The female is much larger than the male, growing to two inches or more. The structure you see at the end of the abdomen is actually called an ovipositor, not a stinger. Ovipositors are structures on female insects in which they deposit eggs. This particular insect deposits eggs into the ground around trees and shrubs. The yellow eggs are about 1/8 inch long developing into larvae which then feed on the living roots of trees and shrubs. One female may lay as many as 100 eggs in clusters. The larvae may be as long as 3 ½ inches with black mandibles (very scary).  Broad-neck root borers prefer deciduous trees of the forest but have been known to feed on fruit trees and shrubs such as peach, pear, apple, blueberries and even grapes. The complete life cycle takes about three years. Adults emerge from the ground between June and August eating the foliage of trees and, on some occasions, even damaging the fruit.  Generally, the adults feed at night but stay hidden during the day. The smaller males are seen more often as they are attracted to light. Broad-necked root borer’s range is from Quebec and Ontario to Minnesota and as far south as Florida.  Because the larva of this insect feeds exclusively on the roots of trees, the only visible symptoms are limb die-back and the yellowing and/or thinning of foliage. Borers can completely destroy young trees and make older trees more susceptible to being blown over.  Prevention is the best way to deal with a borer. Keep grass, leaves, mulch, bark and other litter cleared away from the bases of trees. This prevents the borer from having a place to hide and makes it more visible to predatory birds. In addition, avoid over pruning, over fertilizing and over watering trees – all of these can cause additional stresses. 


Leave a comment

Q: I found these critters dead in my garage after I sprayed the lawn with a pesticide. What are they?

Lawn Shrimp

Lawn Shrimp

A:   These creatures are actually terrestrial amphipods which belong to an order of crustacea.  They look very similar to tiny shrimp therefore they were given the common name of lawn shrimp.  Most amphipods live in salt and fresh water but there are a few terrestrial forms. Even though these terrestrial forms live in our landscapes, they still require a moist habitat. The color of terrestrial species varies from pale brown to greenish to brownish black when alive, but they often turn pink to red when they die. Most amphipods are scavengers feeding off mold which can be found in the mulched areas of our flower beds and shrubbery. Terrestrial amphipods live on the surface (top 1/2 inch) of mulch and moist ground. After rains, large numbers of amphipods can migrate into garages or under the doors of houses. When this occurs, they quickly die as they do not have the protective covering (exoskeleton) of crustaceans or insects.  Because they lack an exoskeleton their bodies quickly lose too much moisture and they die.  However, they come into our homes and garages after heavy rains because their bodies will take on too much water and it can also kill them. Most species are active at night.  Since you found large numbers in the garage already dead, it would be best to sweep or vacuum them up. If you find them in the house, be sure to check the weather stripping around doorways. Since terrestrial lawn shrimp do not transmit diseases nor do they destroy any plant material it is best to leave them alone.  In addition, there are no labeled insecticidal recommendations for control. Think of them more as a nuisance rather than a real pest.  For more complete information, take time to look over the UF/IFAS publication titled, “Terrestrial Amphipods or Lawn Shrimp” at https://edis.ifas.ufl.edu/in377