Mosquitoes breed in standing water

By Audrey Post
MS. GROW-IT-ALL

Q: The recent rains have really soaked my garden and it looks great, but now I’m worried about mosquitoes. Is there anything I can do to keep down an infestation?

A: First, make sure you aren’t inadvertently harboring mosquito breeding grounds. Check for anything that could be a receptacle for standing water, including empty flower pots, pot saucers, children’s toys, even upturned magnolia leaves. Dump any water you see. If you have water bowls for pets outdoors, be sure to change the water in them daily. Ditto for bird baths and containers of water you set out for wildlife.

If you have water that you can’t dump, such as ponds and water gardens, you can buy insecticidal “doughnuts” that kill mosquito eggs but are harmless to birds and other wildlife. Plus, certain plants such as citronella and marigolds seem to have repellant qualities when planted. But be prepared with insect repellant, preferably one that includes a sunscreen. Mosquitoes are simply a fact of life here.

Radio show update: We’ll be talking about plants as insect repellant on this week’s radio show at 6:30 p.m. Thursday at www.blogtalkradio.com/Ms_Grow-It-All. Join us.

More on growing irises: Dael Jones, who has successfully grown bearded irises here and in Dallas, Texas, read last week’s column on growing irises and wrote to share additional tips.

“I have discovered that the main reason they do not thrive here is our high humidity and rainfall in the monsoon season. They will not tolerate continuously ‘wet feet’.” Build a raised bed (at least 12 inches high) and make the soil alkaline with the addition of lime if need be. Make certain the soil mixture is porous enough that it drains well and quickly. If a raised bed is out of the question, large containers will do and have the advantage of being moved to a less visible location when foliage declines.”

In addition, Dael recommends planting or transplanting only in August. One other note to remember: Iris rhizomes should be plant barely beneath the soil, so that the top is exposed. Planting too deeply will result in poor blooms, and the plant will spend its energy literally pulling its rhizome up to the surface.

“As a side note, geraniums suffer the same consequences as iris from "wet feet." Accidentally, I discovered that if I put them in a covered place (under wide eaves, porches, edge of carports, etc.) where the rains do not soak them for days, they will thrive.”

Even with all this care, irises “will not give as abundant blooms as in a climate/soil more suited to their requirements. If, however, you think they are as lovely as orchids, as I do, the effort to grow some is worth it.”

I agree. Thanks, Dael.

Radio Show: "Chill hours"

Why do certain plants thrive in places that get just as hot in summer, but not in the Coastal South? The answer likely is "chill hours," and that was the topic of our conversation this week.

Growing irises in North Florida

By Audrey Post
MS. GROW-IT-ALL

Q: I've grown iris successfully in other parts of the country, but I haven't figured out the secret here. Last fall I moved about 100 irises, which hadn't bloomed in a shady part of my new yard, to a plot of rich soil which gets about six hours of sun a day. The green leaves look very healthy (some of them are 3-4 feet tall) but I have gotten only two blooms even after I fed them a bedding plant mix. What should I do? Where have all the flowers gone?

A: There are several different kinds of irises that will grow here in the Big Bend/Eastern Panhandle of Florida. Those of us who grew up with bearded iris tend to think of them as “the iris,” no other name needed, so that was the first kind of iris that came to mind. You also don’t say in which parts of the country you grew irises successfully, so I’m going with my original guess of bearded iris. They grow vigorously in other parts of the country, but not so here.

Several gardeners I know have had the same problem, and it appears that our region offers barely enough “chill” hours to sustain the plants, but not enough to spur them to bloom regularly. As a result, the plants have to settle in for several seasons and even then, they bloom only sporadically. This past winter’s colder than normal temperatures resulted in better bearded iris blooms locally than we’ve seen in several years, but only for plants that had been established for a couple of years.

Your irises seem to be getting everything they need to perform as well as they can in our area – six hours of sun should be enough. Whatever you do, don’t fertilize them with any of the “bloom-buster” fertilizers that are high in phosphorus – the middle number in the three-number formula such as 10-10-10. Our area is naturally high in phosphorus, and any excess will simply run off, get in the storm-water drainage system and ultimately pollute our streams and springs, causing excess growth of algae.

Reminder: Ms. Grow-It-All’s Internet radio show has moved from Saturday mornings to 6:30 p.m. Thursdays. Go to http://www.blogtalkradio.com/Ms_Grow-It-All to listen; you can call the number listed to join the conversation. If you can’t listen live, all shows are archived and available for download from my Web site, www.msgrowitall.com.

Radio Show: Preparing for hurricane season

In our first broadcast since we moved our show to 6:30 p.m. Thursdays, Eastern time, UF/Leon County, Fla., forester Stan Rosenthal joined us to talk about how to plant a landscape that is hurricane-resistant, as well as what to do for an existing landscape. For a list of the trees he talked about, go to http://treesandhurricanes.ifas.ufl.edu/lessons.html. You can download the show by clicking on the link in the right rail for one week after broadcast; after that, go to my Home Page and click on the radio show archive link. Feel free to add your suggestions in the comment section below.

Use shears, not poison, on tree's suckers

By Audrey Post
MS. GROW-IT-ALL

Q: I have a crape myrtle (Natchez, I think) that is about 10-15 years old. This year there is a cluster of 4 suckers under the tree. If I put Round-Up on the suckers, will it injure the host tree?

A: Most likely. Round-Up is a broad spectrum herbicide whose main ingredient is glyphosate. “Broad spectrum” means it doesn’t target only certain kinds of plants, the way some lawn “weed and seed” formulas do, but will attack whatever it comes into contact with. It’s sprayed on the leaves and absorbed into the plant. It also drips off the leaves and into the soil.

The suckers under your crape myrtle are growing off the base of the tree. If you think of them as new branches that are coming off the root instead of off the trunk, you’ll see that spraying them with Roundup is a bad idea. Use your pruning shears to snip off the suckers. If they’re still tender, hand pruners should do it. If they’ve already begun to develop into a woody trunk, use loppers.

Q: I did not fertilize last spring, I didn't use a “winterizer” fertilizer in early fall and I did not water during any prolonged drought during this past winter. Now I have extensive areas of dead centipede grass that have to be covered over. I live in a sandy area with little topsoil. Of those three lack of actions, please rank these lack of actions from most important to least.

A: Lack of watering is top of the list. I’m not sure any of the others really had anything to do with it. Turfgrass is tough and can bounce back once regular rains or regular watering resumes.

The “winterizer” fertilizer usually contains a pre-emergent herbicide to kill dormant weed seeds. If you have bare spots, the weeds are dead too – likely from lack of water. As for not fertilizing last spring, the main effect of that would have been on your lawn last summer. Was it healthy? If so, skipping a spring fertilizer application probably had little or no effect.

Many gardeners I know don’t fertilize their lawns at all, or do so only in spring. If you fertilize, you need to water more. Because your sandy soil lacks the capacity to hold water, it runs off rapidly. You need to water it regularly, whether you fertilize it or not.

Internet Radio Show: Ms. Grow-It-All’s Internet Radio Show on the Free World Radio Network has moved to 6:30 p.m. Thursdays. My guest host this week is Leon County forester Stan Rosenthal. We’ll be talking about preparing your landscape for hurricane season. Go to http://www.blogtalkradio.com/Ms_Grow-It-All to listen; you can call the number listed to join the conversation. If you can’t listen live, all shows are archived and available for download from my Web site, www.msgrowitall.com.