Twig girdler beetles may be taking toll on red maple
Q: We have a red maple tree that has been looking sick for the past four months. It is 11 years old and about 20 feet tall. The leaves about six inches up a branch will turn completely brown and die. The affected part of the branch just snaps right off like a twig because it is so dead. I fertilized it hoping it would help and new branches grew at the top of the tree. The tree has been so beautiful and we have enjoyed its beauty so much. Is it possible that it is infected with verticillium wilt? Is there anything we can do for it or is it necessary to call an arborist? Madalena Downing, Largo
A: It sounds like twig girdlers, brownish-gray beetles with long antennae about 3/4 inches long. Adults emerge from the ground in late spring and deposit eggs in leaf axils (where the leaf petiole meets the stem). The larvae as they hatch feed under the bark until late summer causing the death of the twig.
As the twigs fall around August-October, the larvae (1-inch worm) crawls into the ground and pupates (changes form and rests over winter) to re-emerge as an adult in late spring to start the life cycle all over again.
The key to breaking the cycle is to prune the twigs back before they fall and pick up any fallen twigs immediately and dispose of in the garbage. Consulting with a certified arborist or pest control company to make an accurate appraisal of the situation is a great idea if tree conditions don't improve.
Ball moss often wrongly blamed for killing trees
Q: This thing has killed our live oak, orange tree among other plants. It is now in my bottle brush tree and according to Lowes and Home Depot there is no spray that I can use to kill this thing. Can you help? Paul Pinet
A: Your photo is none other than ball moss, (Tillandsia recurvata), an epiphyte (air plant) that is very misunderstood. It is not a parasite and draws no nourishment away from the parent plant. It is commonly seen growing on plants in decline, so is often seen as the villain, guilty until proven innocent. It simply attaches to the bark of shrubs and trees (it also attaches to chain link fence), but gains its nourishment from air and water.
If you feel that it takes away from the beauty of your live oak, it can be killed with copper products such as Kocide 101 which is labeled for such a use, or it can be removed by hand. The real issue is, what is killing your landscape. Overwatering perhaps, or just age?
Solving problems with cucumber, zucchini plants
Q: I am growing cucumbers in earth boxes and the leaves, starting at the bottom and working up, become mottled with light colored irregular yellow spots, eventually drying up and dying. I am using Miracle Grow liquid fertilizer .
I have zucchini growing in the ground that form zucchinis 2 or 3 inches long and do not mature. Any recommendations would be greatly appreciated.Mary Priest
A: A favorite host for downy mildew, a fungus disease, is cucumber. The best way to combat downy mildew is to plant varieties that are resistant such as Fanfare, Marketmore 76, Dasher II and Indy for slicers and Calypso, Wellington and Patio Pickle for picklers. Fungicides are effective as a preventative, but lose effectiveness as disease gets a strong hold. Ortho Max Garden Disease Control (chlorothalonil) is effective along with organic products such as BioNeem and Remedy, apply according to label directions. As with any fungus, keep irrigation off of the foliage, have plants in full sun and be ever vigilant for the first spot to hit.
As for the squash, it is probably nematodes (microscopic round worms), prevalent in our Florida sandy soils. They colonize root systems, shutting them down, which is why the fruit forms and then stunts. If you pull the plant up, the root system will be full of knots and galls where the nematodes have colonized. Unfortunately there are no controls. Raised beds or containers eliminate the problem.