| For the Times-Union
Q: I found the new leaves on my pineapple sage all twisted and discolored. What would do that?
A: A number of insects with piercing, sucking mouthpieces could do that. In this case it was whiteflies. They are pretty insidious because they reproduce very rapidly, going from egg to adult within a month. Some are so small screens do not keep them out. Their small size makes it unlikely the gardener will ever see them unless they are in large numbers and fly off in a cloud of white when he or she approaches. On the plant, you need a good hand lens to see them. Most are 1.6 mm in size and fairly translucent.
The damage to your plant will be visible. While the insect is on the underside of the leaf, they will be sucking out sap, and leaving the leaves twisted, with pale spots, silvery white chlorotic spots from the insect removing the chlorophyll from the plant. They are actually after the sweet sap, but the chlorophyll comes along with it, robbing the plant of the ability to make food for itself.
As a homeowner, you want to know how to get rid of the whitefly and it is one of the more difficult cases. It rapidly develops a resistance to insecticides, so if we can avoid using them, we are much better off.
For one thing you would have to buy several kinds of broad spectrum pesticides and rotate them. That’s going to be expensive. And it’s going to kill your natural predators. So, let’s try to get rid of them a more practical way.
There are many natural enemies out there attacking them, so that’s helpful. Parasitic wasps will kill them, ladybugs (aka ladybirds) will gobble them up.
If you have kept a healthy ecosystem in your yard, you have plenty of predators in your yard looking for a meal of these troublemakers.
If not, it’s not too late to start. Reduce or eliminate the use of pesticides in your yard. Make your yard welcoming for birds and pollinators. Provide cover for birds and flowers for pollinators. Provide host plants for butterflies. Enrich your soil with compost so that you have the micro-organisms that feed your plants and produce more nutritious sap and nectar.
You can spray a plant under attack with a blast of the hose. That will dislodge insects and damage those with soft bodies, often leading to death.
It’s been too hot for soaps or oils. They would just burn your leaves.
Q: I have a plant with a blue flower that is spreading. The flower has three blue petals and I’d even think it was pretty if it wasn’t spreading so fast.
A: Good instinct. This plant is a demon with the innocent name of Spreading Dayflower. It will cover lawns or flower beds and is resistant to some weed killers, notably glyphosate, sold as Roundup. Weeds that spring back from nonspecific weed killers are a bit frightening. It loves our heat and rainfall at this time of the year. It will reseed. You cannot pull it, because it will also grow from the tiny pieces of root that get left behind. Ah, it is such a conundrum! I have been battling it for a while.
Sometimes weeds come in with mulch, or from birds, or on plants you buy or on the wind. Once they make contact with the ground, an aggressive weed can grow rapidly and fill out an area. If only our desirable flowers did that!
To control this weed, chemicals are necessary. The chemicals that will work depend on the lawn you have. Consult this document: https://edis.ifas.ufl.edu/ep497 to find which chemical is safe to use in your lawn.
If your problem is in a flower bed, apply the chemical on with a paint brush. I use a foam brush and throw it away after I am finished. I also use a disposable painter’s container so I can rinse it and dispose of it when I am finished with it. Use great care with these chemicals to prevent them from killing desirable plants.
You may have to apply a second application. Follow the direction on the label. The label is the law.
Becky Wern is a Master Gardener Volunteer with the Duval County Extension Service and the University of Florida/IFAS. For gardening questions, call the Duval County Extension Office at (904) 255-7450 from 9 a.m. to noon and 12:30 to 3:30 p.m. and ask for a Master Gardener Volunteer.