September Timely Tending: Wake up the flower beds

By OPAL SCHALLMO and NANCY VOLMAR, Pinellas County Cooperative Extension Service
© St. Petersburg Times
published August 31, 2002

[AP photo] The 4-inch-long lubber variety of grasshoppers are immune to conventional pesticides and too toxic for natural predators.

September is a good month to rejuvenate your flower beds.

Choose annuals that are hardy enough to last all winter and through spring. Some good choices are pansies, petunias, California poppies, nasturtiums, shasta daisies and sweet alyssum. When starting your own plants from seed, it is best to use flats or other containers with sterile soil; transplant seedlings to the garden after they get their true leaves.

It may be necessary to sterilize your flower beds to ensure success. Diseases, such as root rot and damp-off, often kill new plants. Sterilizing also temporarily rids the soil of insect pests and nematodes. The only way a homeowner can sterilize the soil is to cover with clear plastic for a least a month. Contact a pest control company if you want your soil chemically sterilized.

We don't like wet feet

Overwatering houseplants is often the fastest way to kill them. The rule is to water until it runs through the bottom, let the plant drain in a saucer for several minutes, then empty the excess water from the saucer. Watering this way serves two purposes: It washes out the excess salts from fertilizer residue, and it guarantees the entire root system is properly watered.

How often you should water is not easy to say. It depends on the container, the plant and temperatures indoors. Check each day until the soil feels dry about 2 inches deep. This should give you an idea of how long it takes for the soil to dry that deep. You soon will learn how often you must water. It may be once a week or every other day.

A few plants prefer very moist soil, while others can dry out quite a bit before watering. Learn about your plants. Ask your nursery or garden center staff about proper care when you purchase plants.

We can't hide, either

House plants cannot escape insect attacks. It is often a mystery how a plant that has been in your home for several months can suddenly show signs of insect infestation insects, but there is usually a reason. Either you have introduced a new plant with a problem into the home, or the insects were in a dormant or unnoticeable stage for a period of time. Two of the most common insects associated with house plants are fungus gnats and springtails.

The adult fungus gnat is very small and usually dark brown to black. These gnats often are seen flying near windows and around potted plants. Adults may be noticed first when plants are watered. They become disturbed and begin to fly around. The larvae live and feed in the potting soil. The adults do not feed; their only purpose is continuation of the species.

Both larvae and adult fungus gnats are attracted to moist soil. The presence of these flies usually indicates that the plants have been overwatered. Allowing the soil to dry out for a few days or a week may be the best control. The larvae rarely attacks healthy plant roots or stems.

Springtails are also very small insects. They are white when young but darken as they mature. Springtails generally crawl over the surface of potting soil, but a projection at the end of their body allows them to move somewhat like fleas instead of flying. Springtails live in moist soil nearly everywhere in the world. They can infest potted plants if soil from the yard or garden is used. Springtails do not harm healthy plant roots. The adults and young feed on soil debris. As with fungus gnats, allowing the soil to dry out will help control springtails.

Hopping mad

Grasshoppers can ruin lily plants by chewing the young stems to the ground. The lubber variety prefers shrubs, herbs, broadleaf plants and grasses, but they eat almost any plant in sight. Last year's dry winter and a return to normal rainfall this summer have caused an increase in the lubber population.

Young grasshoppers can be controlled by spraying or dusting your plants with Sevin, reapplying as needed for best results. The large yellow-and-black adult lubber is tougher to control because it is too toxic for natural predators and immune to many conventional pesticides. Mechanical control (such as knocking them into a bucket of soapy water) is recommended.

When garden friends turn ugly

Stinging insects such as hornets, yellow jackets and mud daubers are all wasps. They are generally considered beneficial because they attack and destroy many harmful insects around homes and gardens. Hornets and yellow jackets kill house flies, blow flies and various caterpillars. They nest above and below ground, and some are very aggressive.

So, even though they are beneficial it may be necessary to control them if they pose a threat to people. Wasp and hornet control is best left to professionals. You can purchase a product called "wasp and hornet spray" for use on small wasps nests. Use it late in the evening when all insects are on the nest. You should be able to stand away from the nest to spray. This product is advertised as a quick knockdown, so insects should not swarm after you. Remember, large nests should not be tackled by a homeowner.

Love dances again

The second flight of the lovebug takes place during late August and September. These flights may last for four to five weeks. Lovebugs do not become active until about 10 a.m., so motorists can avoid most of the mess on their cars by traveling at night. Traveling at slower speeds also will reduce the amount of bug splatter. A large screen placed in front of the grill will keep the radiator vents from clogging and also will protect the car's finish.

Splattered bugs should be washed off the car as soon as possible. They are easier to remove and damage to the car's finish is less likely if the car has been waxed recently. When the remains are left on an unwaxed car for several days, the finish can be permanently damaged.

Soaking for several minutes with water aids removal. When lovebugs are numerous, some motorists spread a light film of baby oil or antistick cooking spray over the hood's front, above the windshield and on the grill and bumper, which makes lovebug removal a simpler task.

Love your lawn

This is the month to fertilize lawns. Fertilizer applications are effective only when applied correctly. A complete fertilizer such as 16-4-8, 12-12-12, 6-6-6 or any other comparable mixture may be used. Spreader calibration is important, not only to ensure good coverage but also to avoid damage from over-application. To obtain a free fact sheet, send a self-addressed, stamped long envelope to: How to Calibrate Your Fertilizer Spreader, 12175 125th St. N, Largo, FL 33774-3695.

Love all your plants

Plants to fertilize this month are azaleas, gardenias, camellias, ixoras, palms and ornamental trees whose trunks are smaller than 6 inches. Larger trees also can be fertilized if desired. Other plants to feed this month are avocados, bananas, bromeliads, grapes, papayas and early vegetables.

This should be the last fertilization of the year for many plants. Fertilizer is important to help maintain healthy conditions. It also prepares the plants for cold weather. A healthy plant can withstand adverse conditions much better than a weak, neglected plant.

Fruit-bearing citrus trees 10 years and older should receive 10 pounds of 4-6-8, 4-8-8 or similar fertilizer. These applications should be made every four months (January/February, May/June, September/October). Younger trees need a smaller amount but more frequent applications. First-year trees should receive 3/4 to 11/2 pounds of fertilizer five to six times a year. Second-year trees need 13/4 pounds of fertilizer four to five times each year. Starting in the third year, apply 3 pounds, increasing each year until the trees are 10 years old. Broadcast the fertilizer under the tree canopy, and water thoroughly to move the nutrients into the root zone. Remember, trees older than 10 years still get only 10 pounds of fertilizer at each application.

Much ado about mulch

To mulch or not to mulch citrus, that is the question we hear over and over again from concerned homeowners. Experts discourage mulching citrus trees because it increases humidity and provides a favorable place for fungus to grow. Although mulching may not cause any permanent damage to your citrus tree, there is always the possibility that foot rot will develop from moisture being held close to the trunk by mulch.

Foot rot can weaken or even kill citrus trees and often goes undetected when there is mulch or grass growing around the base. Grass and weeds will also compete with the citrus trees for water and nutrients. If you must mulch, keep it at least 12 inches from the trunk.

Ornamental plants, on the other hand, enjoy being mulched. Mulch can be applied to a depth of 2- to 3-inches around trees and shrubs, although it is still a good idea to keep mulch a few inches away from the stems or trunks of ornamental plants to prevent stem rot.

As mulch decomposes and filters into the soil, more mulching material should be added to the older layers for maximum benefits. Several cities, as well as some counties, offer free mulch. All you need is a container and a shovel or pitchfork for loading. For information on the site locations in Pinellas, please call (727) 464-6001.

Prune and preen

The first step in pruning a shrub is to remove all dead, diseased, or injured branches. Pruning shears and saws should be dipped in a solution of water and alcohol or water and bleach, such as Clorox, to prevent spread of disease. A 9-to-1 ratio is fine. Remove branches that cross each other and those that look out of place. If the shrub is still too thick, remove older branches. Cut back excessively long growth to a bud or lateral branch that is 4 to 6 inches below the average branch length.

The shrub can be further reduced in size by cutting back each branch 4 to 6 inches to the bud. Do not use hedge shears. It is best to cut each branch separately with hand shears to avoid a ragged cut that may allow disease to enter. This will maintain a neat, informal shrub that retains its natural shape.

A properly pruned shrub is a work of art. Shrubs should look natural to fit into the landscape. Plants sheared into various geometric shapes produce a formality more suitable for a botanical garden. Of course, if you have lots of time and energy a formal garden may be your cup of tea.

Pruning bougainvillea should be done before the middle of September to ensure good blooms this winter. Fertilize with 5-10-20, 8-10-12 or other similar mixture labeled for acid-loving plants.

This is the last chance of prune your poinsettias. The rule of thumb is not to prune after Labor Day. Keep your plants watered and fertilize with the same formula used for bougainvillea. Yellow lower leaves may indicate a magnesium sulfate deficiency. Apply according to label directions for herbaceous perennials.

Here come the chrysanthemums

Chrysanthemums should be budding now for their fall bloom. Septoria leaf spot is one of the diseases that may attack the plants at this time of year. The disease first appears as small grayish-brown, circular spots on the leaves, with the center of the spots sometimes becoming brittle and falling out, which gives the appearance of damage by chewing insects. The infection will gradually discolor an area between the veins. You can treat with Daconil 2787, Kocide 101 or other approved fungicides.

Mighty assault

Keep a watchful eye for spider mites on azaleas, gardenias, juniper, vegetables and many other landscape plants. The first signs of an infestation may be a dusty look to the leaves or needles. Then a stippling pattern appears, the leaves turn yellowish to brown and webs may be visible. Sprays of Ultra-fine oil, Insecticidal Soap, Orthene, Malathion or other labeled pesticides can be used to control mites. Read and follow label instructions: Some plants are sensitive to soaps and certain chemicals.

The subject is roses

A weekly spraying of a fungicide on roses can help keep black spot and other diseases from defoliating your plants. Rake up any fallen leaves and remove all dead wood from your rose bushes. Daconil, triforine (Funginex), Fore or Dithane M-45 work; apply according to label directions.

-- Compiled by Opal W. Schallmo and Nancy R. Volmar of The Pinellas County Cooperative Extension Service. If you have questions, call them at (727) 582-2100.

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