The “Dog Days” are the hottest, muggiest days of summer. In the northern hemisphere, they usually fall between early July and early September. The actual dates vary greatly from region to region, depending on latitude and climate. It is miserable right now, but fall is coming.
In ancient times, when the night sky was not obscured by artificial lights, the Romans used the stars to keep track of the seasons. The brightest constellation, Canis Major (Large Dog), includes the “dog star”, Sirius. In the summer, Sirius used to rise and set with the sun, leading the ancient Romans to believe that it added heat to the sun. Although the period between July 3 and August 11 is typically the warmest period of the summer, the heat is not due to the added radiation from a far-away star, regardless of its brightness. The heat of summer is a direct result of the earth’s tilt.
Spending time outdoors this time of year is uncomfortable, potentially dangerous, due to the intense heat. However, the chinch bugs are very active in St. Augustine grass (for more information: http://edis.ifas.ufl.edu/lh036), and the summer flowers need water. So, take care of those tasks early in the day and then retreat to the air conditioning to plan your fall planting.
Plant tomato plants in August for fruit in October. Varieties such as Phoenix, Florida 91, Solar Set and Heat Wave II are good selections for setting fruit in high temperatures, should summer temperatures continue. Otherwise, try some of the newer UF/IFAS recommended varieties for fall planting in North Florida such as Bella Rosa, Tribute or Finishline. For more information on tomato selection refer to: http://edis.ifas.ufl.edu/in756. For information on other vegetables for fall gardening refer to the Florida Vegetable Gardening Guide: http://edis.ifas.ufl.edu/vh021.
Many bedding plants flower quickly and can add color to the fall landscape. These include pentas, African marigolds, torenia, zinnias, melampodium and scaevola. Other can be planted in October for blooms all winter-long. Plan spaces and color themes for calendulas, pansies, snapdragons and violas. Add in ornamental cabbage or kale and some dusty miller to accent the garden. They too will perform through the cold. For more information on Annuals for the Florida Garden refer to: http://edis.ifas.ufl.edu/mg319.
Dependable fall blooming perennials include lion’s ear (Leonotis leonurus), pineapple sage (Salvia elegans), firebush (Hamelia patens), cigar plant (Cuphea micropetala), yellowbells (Tecoma stans) and firespike (Odontonema strictum). Also, garden mums (Chrysanthemum sp.) and many different Irises will add color again in the spring. To gain information on perennials for Florida refer to: http://edis.ifas.ufl.edu/mg035.
Webster’s second definition of “dog days” is a period of stagnation or inactivity. But, even when the heat forces you to slow down on the labor-intensive work, there is plenty of gardening “activity” to do. Stay in the air conditioning and plan that spectacular fall and winter yard.
You may recognize the arrival of summer because of the intense buzzing sound coming from the trees. It can last all day long, with changes in the pitch and pattern of the screaming.
Dusk-calling cicada, Tibicen auletes (Germar). Total length (head to tips of forewings) is 64 mm (about 2 1/2 inches). Photograph by Lyle J. Buss, University of Florida.
Cicadas are large (3/4” – 2 ½”) winged insects with stocky bodies and bulging eyes. They spend the vast majority of their lives underground, emerging in massive numbers for just a few weeks to mate and lay eggs. This behavior often earns them the name “locusts,” which entomologically they are not.
In much of the eastern United States, periodical cicada (Magicicada spp.) broods rise up out of the ground every 13 or 17 years. In the summer of 2024, two different broods (one group of 13-year cicadas and one group of 17-year cicadas) will arrive at the same time across 16 states. The closest to us will be mid-lower Alabama. Approximately one trillion insects are anticipated. This only happens once every 221 years.
By emerging in large numbers, the cicadas are able to reduce the potential of being eaten by predators. Though many will be lost to birds and killer wasps, enough will survive to be able to reproduce.
Unlike the broods of periodical cicadas, populations of Florida’s 19 cicada species produce adults every year. However, the nymphs still spend several years developing underground. The nymphs use their piercing-sucking mouthparts to feed on the xylem sap in the roots of trees. The feeding can weaken already stressed trees. Most trees tolerate the damage quite well. After gaining enough nutrients, the nymphs wait for the soil to warm enough (approximately 64° F. at six inches deep) before crawling out of the ground, climbing up the tree trunk, and molting into adults with wings. You can often find the empty shed exoskeleton still hanging on the tree trunk.
The adult male spends all day being as loud as possible in order to attract the girls. Each species has its own song. Large numbers of insects create more noise. Male cicadas have a pair of tymbals located on the sides of their abdomen. Tymbals are corrugated regions of the cicada’s exoskeleton that can be vibrated so rapidly that the clicking sound becomes a high-pitched buzz. Cicadas with the best abs get the girls and reminds all the humans that summer is here.
Cicada (Tibicen sp.) escaping its nymphal skeleton. The cast skeleton will remain attached to the tree. Once free, the adult will expand its wings, darken, and fly away. Photograph by Lyle J. Buss, University of Florida.
Extended spring weather with cool nights and frequent rain can be enjoyable for humans, but does strange things to plants, especially if dormant fungi are hanging around. Exobasidium vaccinii is a fungus that is believed to overwinter as spores attached to bark and bud scales. It can cause infection with the opening of buds in spring, creating odd shaped leaves and flowers that are referred to as galls. Infection is dependent on high humidity and moisture during bud break. Gall growth is due to plant cell division resulting from the stimulus of hyphal growth within host tissue. When galls are still soft, the fungus grows between epidermal cells, breaks the cuticle, and sporulates giving the gall a white cast. Either all or part of a leaf may become thickened, fleshy, and covered with a white bloom of spores. At first, diseased leaves are succulent and white, but they later shrink into hard, brown, gall-like bodies. Galls are composed of fungus-infected plant tissue. Older leaves are resistant to infection. Exobasidium vaccinii is most common in azaleas and camellias.
Photo by Sheila Dunning
But, other Exobasidium species are floating out there, and with just the right conditions they can deform other plants. That’s what caused this odd formation on one flower of a gardenia plant. In this case, the spores fused the sepals to the petals of the flower.
Photo by Margaret Stewart
While chemical controls are available, they would need to begin before symptoms appear and continue until the gall dried completely. It may be an option for the fastidious weather watcher with a good working knowledge of this disease. But, for the rest of the population, removing and destroying galls before they turn white is the best management practice to avoid having spores form and hang around until next spring. Proper pruning of the plants to improve air circulation will also reduce the chances of favorable conditions, should there be an extended cool, wet season next year.
What is a titi? Google it. Wiktionary says it is “a New World monkey of the genus Callicebus, native to South America, distinguished by their long soft fur”. But deeper into the definitions you will find “a shrub or small tree of the southern Unites States, having glossy leaves and elongated clusters of flowers, occurring in wet soil conditions”.
Titi is just a common name for two species that grow in the wetlands. Black titi (Cliftonia monophyla), also referred to as buckwheat tree, is the first to bloom in the spring. Native seedlings produce clusters of small white flowers at the tip of the branches. The sweet-smelling blooms provide a nectar source for bees in February and March. Following pollination, golden-brown seed pods will form, resembling buckwheat grains; hence, the other common name. The seed persists through the fall, providing added aesthetics and a food source for native and migratory birds. Pink-flowering sports of the Black titi have been propagated for the native plant nursery trade. ‘Chipolo Pink’ is one of the most popular (pictured).
The other species is Red titi (Cyrilla racemiflora), also called Swamp titi. It will send out multiple drooping white flowers in a finger-like cluster from the previous year’s wood. Blooming begins in the late spring and continues into the summer. Unfortunately, the nectar has shown to be a source for purple brood disease in bees, a terminal condition for the baby bees.
So, when deciding on native plants for your wetlands edge or rain garden, look for the Black titi and the new cultivars on the market. Then research other summer-flowering nectar sources like Clethra alnifolia, Sweet pepperbush, and their many new cultivars.
Winter is probably the easiest time of year to kill the plant you brought in from the cold. And, the fastest way is by overwatering. Grueling growing conditions like lower light levels, dry air, shorter days and chilly temperatures really stress out plants, which makes them susceptible to insect and disease problems. Then the pests finish them off.
The secret to helping plants survive winter is adjusting care routines to suit seasonal growing conditions. Here are a few things to consider.
Light
In winter, the sun is lower in the sky and light levels near windows drop up to 50 percent. Houseplants that grow near a sunny eastern or northern window in summer may need a southern or western exposure in winter. Likewise, tropical plants that were able to withstand direct sun outside will need to be in the brightest spots possible or may require extra lighting inside. Plants are likely to lose leaves in order to adjust to the light change. The new leaves that grow back will be accustomed to the lower light. Remember that if those plants are going back outside in the spring. They will need to be shaded for a while or the new leaves will sunburn.
To help plants cope with changing light levels:
Move plants closer to windows, if possible.
Clean windows to allow maximum light transmission.
Shift plants to new locations near brighter windows for winter.
Wash dust off plants so leaves can make maximum use of available light.
Add artificial light. Fluorescent bulbs provide adequate light. They’re cheaper than traditional grow lights and produce less heat. Position bulbs 4 to 12 inches away from plants for effective results.
Temperature
Most of these plants and prefer temperatures between 65° F and 75° F during the day and about 10-15 degrees cooler at night. For tropical plants, temperatures below 50°F can cause problems. Hopefully, you had the chance to bring them in with the first cool spell a month ago.
Adjust thermostats for your comfort, but remember your plants need some consideration.
Avoid placing plants near cold drafts or heat sources.
Keep plants several inches away from exterior windows.
Humidity
Homes may offer only 5-10 percent relative humidity in winter. Houseplants like 40-50 percent. Signs of low humidity stress on plants include brown leaf tips and appearance of pests like spider mites.
Raise humidity around plants with a room humidifier.
Place plants on a pebble-lined tray filled with water. Keep the water level just below the pebbles. As the water evaporates, it raises humidity around plants.
Mist plants with room-temperature water. Avoid wetting walls or furniture.
A spider plant on a coffee table. Photo Credit: University of Florida/IFAS
Water
The most common problem plants suffer from in winter is overwatering. Most plants need soil to dry out almost completely before watering. How can you tell if plants need water?
Don’t just spot test the soil surface. Plants need water when the root zone is dry. Poke your finger into soil up to 2 inches. If the soil is dry, water.
Lift the pot. Soil is lighter when it’s dry. Learn how wet soil feels by lifting pots immediately after watering.
Exceptions to drying out between watering: Potted citrus and ferns require consistently moist soil. Always research plant moisture needs if you’re unsure.
When you do water, never allow plants to sit overnight in water that collects in the drainage saucer.
Fertilizer, Pruning and Repotting
Save these tasks until spring. Winter growth is usually leggy. Prune and fertilize to encourage bushy growth when the sunlight and temperatures increase. The right time to repot most tropical and houseplants is during periods of active growth – in spring and summer. The exception is potted woody plants that go completely dormant in winter. Transplant those prior to bud break in early spring.
