How Florida Weather Can Affect Your Lawn and Ornamentals

Winter -

      Seeing your lawn turn brown during the winter can be worrying for some homeowners; however, this is a normal part of your lawn's winter dormancy. Come spring time your lawn should rebound and begin producing new green growth. For homeowners who want to know about the health of their grass without waiting until spring, planting small plugs of grass from your lawn in a pot can help you determine if your grass is simply dormant or truly damaged. To do this, cut small plugs of the grass with the roots still attached from your lawn and plant them in a pot. Place the pot in a warm spot that will receive sunlight and see if the grass begins to grow. Excess foot and vehicle traffic may worsen the effects of cold damage, so stay off damaged turf until the soil and plants have completely thawed. Give your lawn some time to recover before mowing. When you do mow, be sure to cut the grass to the highest recommended height for your specific type. Cutting the grass too short could make it harder for your lawn to recover from cold weather damage. If your lawn does not recover in the spring, you may have to replace some of the grass with sod pieces or plugs. Just remember, brown grass doesn't necessarily mean dead grass.

      All of our warm season turf grass species go into some degree of dormancy during the winter months, slowing their growth down and they may or may not stay green (less mowing required!). This is a natural cycle, regardless of where you live in the state and you should work to keep your lawn as healthy as possible through mowing, irrigating, and fertilizing practices. You should keep mowing height high year-round for additional enhanced stress tolerance (3.5" to 4" for most St. Augustine grass cultivars and Bahia grass, and 2" to 2.5" for Centipede grass and coarse-textured Zoysia grass lawns). Do not "scalp" the lawn, as this makes it less able to recover from freeze damage. After a freeze, check the soil around your plants. Plants may not be getting the water they need if the soil has dried out or if the water in the soil is frozen. Watering the area can help defrost the soil and provide your plants with an available source of moisture. Even injured plants need water. January and February are the coldest months in Florida, and plants can be damaged by low temperatures. But with your help, cold-damaged plants can often recover.

      If your lawn does not recover come springtime, remove the decayed vegetation from the affected areas and replace with either sod pieces or plugs. Do this before weeds have a chance to germinate and take hold of the ground. It is possible that not all of your lawn will be affected, perhaps just those areas that are most exposed to the cold temperatures.

      Don't prune cold-damaged plants right away. The dead foliage looks bad, but will help insulate plants from further injury. In the spring, assess the extent of the damage by scraping the bark with your fingernail. Cold-injured wood will be black or brown under the bark. To be certain where to prune, wait until plants begin to sprout new growth.

      Herbaceous plants like impatiens and begonias that are damaged by the cold may collapse. If this happens, it's best to cut them down and remove the plants to prevent fungal or bacterial problems from arising as they decay.

Spring/Summer -

      Pests are drawn to the favorable conditions that support shrubs and ornamentals. Due to the favorable growing conditions for tropical ornamental plants and shrubs in the Sunshine State, a variety of plants are suitable for these warm, humid conditions. Selecting the right plants and shrubs makes a difference when trying to keep pests away for several reasons, including:
- Making sure your choice of plants is suitable for the light and water conditions on your property – essential to growing a healthy landscape.
- Making sure your plants are non-invasive. Invasive plants may look pretty when planted but tend to overwhelm your landscape and take over, crowding out your other plants.

      It’s no surprise that your selection of flowering and woody beauties are fair game to several Florida pests that are gearing up in summer to devour them. Along with fending off pests and diseases, such as fungi and mildew, the weather, fertilization, and watering also play a role in keeping your shrubs and ornamentals happy and healthy this summer.

      Watering too much can cause root rot with shrub and ornamental leaves turning yellow and eventually falling off your plants. Watering too little can cause wilting and weaken plants that are less hardy than others. Weather conditions can also play a role in increased insect activity. Dry spells, often accompanied by strict watering schedules and restrictions can cause mites to feed on plants as a water source. On the opposite end of the spectrum, a lot of rain, not something you can control, but be sure you are not watering your plants in addition to large amounts of rain they may have received. Keeping your landscape plants watered properly and well-fed is one of the best things you can do to fend off environmental stresses, fungi, diseases, and pests. Stressed plants send out plant pheromones that attract insects to weakened plants along with the healthier shrubs and ornamentals nearby.

      Insects that can cause significant damage to Florida shrubs and ornamentals include the following:
- Grasshoppers and caterpillars with chewing mouthparts – Caterpillars and grasshoppers cause visible damage, showing up as ragged leaf edges, holes in leaves, and other missing tissue. Eastern lubber grasshoppers can attack in large numbers and actually defoliate landscape plants.
- Aphids, scales, spider mites, and notorious whiteflies use their piercing-sucking mouthparts – these insects cause lateral damage to leaves, these pests move across leaves causing yellowing or browning of leaves and possible wilting with their strong mandibles. Aphids can affect every part of the plants they attack. Many common plants such as Ixoras, Hibiscus, Camellia, Crepe Myrtle, Gardenia, Oleander, Photinia, Roses, and Viburnum are very susceptible to piercing-sucking insects.
- Leaf miners burrow into the leaves of plants leaving tell-tale tunnels in the leaves, such as well-known citrus leaf miners, which are actually the larval stage of a moth.
- Gall makers crawl into plant tissue – typically leaves, stems, or twigs, causing leaf tissues to swell. Blueberry gall midge larvae burrow into leaves to feed and gall wasps deposit their eggs into plant tissues.
- Wood/phloem borers cause damage, feeding on living wood, such as twig girdlers and powder post beetles.

      Just as different insects cause damage to different plants, treating for pests can be challenging, as well. Some insects are resistant to insecticides while some treatments for insects may make the situation worse by also eliminating beneficial insects that prey on those pests.

Fall -

      Even though a Florida fall isn't very cold, it’s still a good time to start preparing your lawn for cold weather. Shorter days, lower light intensity, and cooler temperatures result in slower-growing lawns.

      Centipede and St. Augustine lawns are very susceptible to large patch fungus disease in the fall. Water early in the day to avoid long periods of leaf wetness. Apply fungicides if you’ve had repeated problems with this disease. Scout for sod webworms, as this is the time of year that they can become very destructive, with little time for turf recovery before winter dormancy.

      You can also try over-seeding. It's when you plant a temporary grass to provide a green lawn all winter. Rye grass is popular for over-seeding because of its fast growth and low cost. It should be sown once daytime highs have fallen to the low- to mid-70s. Rake the grass to remove all debris, then mow your lawn before sowing the seed. You'll need to water your over-seeded lawn frequently until it has germinated. Once the winter lawn is established, it will require watering, mowing, and fertilizing. Grasses used for over-seeding will die off as temperatures rise in the spring.

Image is reused under the GNU Free Documentation License