Q. I have a camellia plant that is about 25 years old. It forms flower buds but the buds never fully open. The plant otherwise looks healthy. Is there something that I’m doing or not doing that causes this?
Sasanqua camellia bloom, Photo credit: Larry Williams
A. I have seen this happen over the years. There are a number of possibilities for why this happens. If the camellia cultivar is otherwise known to do well in the area, the problem could be caused by one or more of these factors.
- Stress (primarily drought stress could inhibit buds from opening)
- Freeze damage
- Too many buds on the plant to allow each and every bud to open
However, with this being the norm for your camellia plant for that many years, it may be the wrong camellia variety in the wrong place.
Camellias have been so common in our Southern landscapes that some people think they are native to our area. However, camellias are native to Asia. They were first brought to America during the latter part of the 1700’s.
Years ago, people planted any camellia they could get their hands on because camellias weren’t as common or available and definitely had a more limited selection.
Some camellia cultivars are simply not well adapted to the Gulf Coast and, as a result, will not flower well even though they may grow well here. This is why some varieties are favored in Seattle, some do better in California, some do better in New England and others perform well here in the South.
Even though camellias are a common sight in shady Southern gardens now, not all camellias will perform well here. So, it is important to do some homework before purchasing and planting just any old camellia.
As stated in the UF/IFAS Extension publication Camellias at a Glance, “There are numerous species of Camellia, but the types commonly grown as landscape shrubs in Florida are Camellia japonica, Camellia sasanqua, and hybrids of these.” This publication is available online at https://edis.ifas.ufl.edu/pdffiles/EP/EP00200.pdf or from the UF/IFAS Extension Office in your County.
Sasanqua and japonica camellias come in whites, pinks, reds, double and single flowers and sizes from four to twenty feet tall.
The sasanqua types bloom as early as October while the japonica types begin flowering later.
It is possible to select a few different varieties, instead of just one, to extend the color in your landscape from weeks to months. Selecting camellias for staggered flowering times can provide color all fall and winter long.
When purchasing camellias, research the bloom times of varieties for your area.
No previous experience or accreditation it required to be a landscaper in the state of Florida. So when homeowners are searching for service providers, it is important that they question potential companies about their skills. One good measure is completion of voluntary certifications such as the Florida Nursery, Growers and Landscape Association (FNGLA) Certified Horticulture Professional (FCHP). The FCHP program has been the industry’s standard for measuring horticulture and landscape knowledge since 1984. The training is also useful for property managers, homeowner associations and retail garden center employees, or anyone that wants to know more about Florida’s plants and their care.
Plants are complex and variable living things that range from microscopic to the largest of living organisms. With steady population growth in the state of Florida, environmental damage risks created by the use of improper products and practices has continually risen. State and federal natural resource protection agencies have restricted certain horticultural practices, as well as, fertilizer and pesticide application. It takes scientific knowledge to maintain lawns and landscapes, not just a “green thumb” in order to keep plants healthy while reducing contamination to the soil, air and water that we all need.
The Florida Certified Horticulture Professional training covers 16 areas, including identification, fertilization, irrigation, pest management, safety and business practices. Lecture and hands-on activities are utilized at each session. The 70-hour course will enhance anyone’s knowledge and will provide the basis for professionals to deliver a skilled service to clientele.
If you are a green industry worker or a concerned citizen interested in attending a FCHP preparatory course, there is an opportunity here in Crestview. Beginning Thursday, January 16, 2020 and continuing for 10 weeks to March 19, 2020, the Okaloosa County Extension office will be providing training for $175, which included the newest hard copy manual. Contact Sheila Dunning, 850-689-5850, email@example.com for more information.
Last week at the Panhandle Fruit and Vegetable Conference, Dr. Ali Sarkhosh presented on growing pomegranate in Florida. The pomegranate (Punica granatum) is native to central Asia. The fruit made its way to North America in the 16th century. Given their origin, it makes sense that fruit quality is best in regions with cool winters and hot, dry summers (Mediterranean climate). In the United States, the majority of pomegranates are grown in California. However, the University of Florida, with the help of Dr. Sarkhosh, is conducting research trials to find out which varieties do best in our state.
In the wild, pomegranate plants are dense, bushy shrubs growing between 6-12 feet tall with thorny branches. In the garden, they can be trained as small single trunk trees from 12-20 feet tall or as slightly shorter multi-trunk (3 to 5 trunks) trees. Pomegranate plants have beautiful flowers and can be utilized as ornamentals that also bear fruit. In fact, there are a number of varieties on the market for their aesthetics alone. Pomegranate leaves are glossy, dark green, and small. Blooms range from orange to red (about 2 inches in diameter) with crinkled petals and lots of stamens. The fruit can be yellow, deep red, or any color in between depending on variety. The fruit are round with a diameter from 2 to 5 inches.
Fruit, aril, and juice characteristics of four pomegranate cultivars grown in Florida; fruit harvested in August 2018. a) ‘Vkusnyi’, b) ‘Crab’, c) ‘Mack Glass’, d) ‘Ever Sweet’. Photo Credit: Ali Sarkhosh, University of Florida/IFAS
A common commercial variety, ‘Wonderful’, is widely grown in California but does not perform well in Florida’s hot and humid climate. Cultivars that have performed well in Florida include: ‘Vkusnyi’; ‘Crab’; ‘Mack Glass’; and ‘Ever Sweet’. Pomegranates are adapted to many soil types from sands to clays, however yields are lower on sandy soils and fruit color is poor on clay soils. They produce best on well-drained soils with a pH range from 5.5 to 7.0. The plants should be irrigated every 7 to 10 days if a significant rain event doesn’t occur. Flavor and fruit quality are increased when irrigation is gradually reduced during fruit maturation. Pomegranates are tolerant of some flooding, but sudden changes to irrigation amounts or timing may cause fruit to split.
Two pomegranate training systems: single trunk on the left and multi-trunk on the right. Photo Credit: Ali Sarkhosh, University of Florida/IFAS
Pomegranates establish best when planted in late winter or early spring (February – March). If you plan to grow them as a hedge (shrub form), space plants 6 to 9 feet apart to allow for suckers to fill the void between plants. If you plan to plant a single tree or a few trees then space the plants at least 15 feet apart. If a tree form is desired, then suckers will need to be removed frequently. Some fruit will need to be thinned each year to reduce the chances of branches breaking from heavy fruit weight.
Anthracnose caused by Colletotrichum sp. to pomegranate fruit. Photo Credit: Gary Vallad, University of Florida/IFAS
Anthracnose is the most common disease of pomegranates. Symptoms include small, circular, reddish-brown spots (0.25 inch diameter) on leaves, stems, flowers, and fruit. Copper fungicide applications can greatly reduce disease damage. Common insects include scales and mites. Sulfur dust can be used for mite control and horticultural oil can be used to control scales.
A couple weeks ago, I was on a site visit to check out some issues on Canary Island Date Palms. The account manager on the property requested a site visit because he thought the palms were infested with scale insects. He noticed the issue on a number of the properties he manages and he was concerned it was an epidemic. From a distance, lower fronds were yellowing from the outside in and the tips were necrotic. These are signs of potassium deficiency with possible magnesium deficiency mixed in.
Transitional leaf showing potassium deficiency (tip) and magnesium deficiency (base) symptoms. Photo Credit: T.K. Broschat, University of Florida/IFAS Extension
Nutrient deficiencies are slow to correct in palm trees. It’s much easier to prevent deficiencies from occurring by using a palm fertilizer that has the analysis 8N-2P2O5-12K2O+4Mg with micronutrients. Even if the palms are part of a landscape which includes turf and other plants that require additional nitrogen, it is best to use a palm fertilizer with the analysis previously listed over a radius at least 25 feet out from the palms. However, poor nutrition wasn’t the only problem with these palms.
Upon closer look, the leaflets were speckled with little bumps. Each bump had a little white tail. These are the fruiting structures of graphiola leaf spot also known as false smut.
Graphiola leaf spot (false smut) on a Canary Island Date Palm. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Graphiola leaf spot is a fungal leaf disease caused by Graphiola phoenicis. Canary Island Date Palms are especially susceptible to this disease. Graphiola leaf spot is primarily an aesthetic issue and doesn’t cause much harm to the palms infected. In fact, the nutrient deficiencies observed in these palms are much more detrimental to their health.
Graphiola leaf spot affects the lower fronds first. If the diseased, lower fronds are not showing signs of nutrient deficiencies then they can be pruned off and removed from the site. All naturally fallen fronds should be removed from the site to reduce the likelihood of fungal spores being splashed onto the healthy, living fronds. A fungicide containing copper can be applied to help prevent the spread of the disease, but it will not cure the infected fronds. Palms can be a beautiful addition to the landscape and most diseases and abiotic disorders can be managed and prevented with proper pruning, correct fertilizer rates, and precise irrigation.
Damage caused by azalea lace bug, Stephanitis pyrioides (Scott), feeding. Photograph by James. L. Castner, University of Florida. Severely damaged leaves become heavily discolored and eventually dry or fall off. Symptoms may sometimes be confused with mite injury, but the presence of black varnish-like excrement, frequently with cast skins attached, suggest lace bug damage (Johnson and Lyon 1991).
You may be noticing the color disappearing from your azaleas right now. Do your azaleas look bleached out from a piercing-sucking insect. The culprit is probably azalea lace bug, Stephanitis pyrioides. This pest overwinters in eggs on the underside of infested leaves. Eggs hatch in late March and early April. The insect then passes through five nymphal instars before becoming an adult. It takes approximately one month for the insect to complete development from egg to adult and there are at least four generations per year. Valuable plants that are susceptible to lace bug damage should be inspected in the early spring for the presence of overwintering lace bug adults, eggs and newly-hatched nymphs. Inspect these plants every two weeks during the growing season for developing lace bug infestations.
Both adults and nymphs have piercing-sucking mouthparts and remove sap as they feed from the underside of the leaf. Lace bug damage to foliage detracts greatly from the plant’s beauty, reduces the plant’s ability to produce food, decreases plant vigor and causes the plant to be more susceptible to damage by other insects, diseases or unfavorable weather conditions. The azalea can become almost silver or bleached in appearance from the feeding lace bug damage.
However, lace bugs often go undetected until the infested plants show severe damage sometime into the summer. By then several generations of lace bugs have been weakening the plant. Inspecting early in the spring and simply washing them off the underside of the leaves can help to avoid damage later and the need for pesticides.
Adult lace bugs are flattened and rectangular in shape measuring 1/8 to 1/4 inch long. The area behind the head and the wing covers form a broadened, lace-like body covering. The wings are light amber to transparent in color. Lace bugs leave behind spiny black spots of frass (excrement).
Adult azalea lace bug, Stephanitis pyrioides (Scott), and excrement. Photograph by James. L. Castner, University of Florida.
Lace bug nymphs are flat and oval in shape with spines projecting from their bodies in all directions. A lace bug nymph goes through five growth stages (instars) before becoming an adult. At each stage the nymph sheds its skin (molts) and these old skins often remain attached to the lower surface of infested leaves.
Nymphs of the azalea lace bug, Stephanitis pyrioides (Scott), with several cast skins and excrement. Photograph by James. L. Castner, University of Florida.
Azalea lace bug eggs are football-shaped and are transparent to cream colored. Lace bug eggs are found on the lower leaf surface, usually alongside or inserted into a leaf vein. Adult females secrete a varnish-like substance over the eggs that hardens into a scab-like protective covering.
Other plant species, such as lantana and sycamore, may have similar symptoms. But, realize that lace bugs are host specific. They feed on their favorite plant and won’t go to another plant species. However, the life cycle is similar. Be sure to clean up all the damaged leaves. That’s where the eggs will remain for the winter. Start next spring egg-free.
For more information go to: http://entomology.ifas.ufl.edu/creatures/orn/shrubs/azalea_lace_bug.htm
Reddish, round spots are the first sign of Entomosporium Leaf Spot on Indian Hawthorn. Photo credit: Beth Bolles, UF IFAS Extension
Indian hawthorn (Rhaphiolepis spp.) is one of those great evergreen shrubs with such a reputation for hardiness that most folks tend to plant it and not worry about it. Indian hawthorn is not a Florida native, but is adapted to our weather conditions and is widely used in home landscapes throughout the Southeast.
However, it is important that homeowners and landscape managers pay attention to them, particularly during the warm, often wet weather growing season. During such conditions, the plant is vulnerable to Indian hawthorn leaf spot, caused by a fungus called Entomosporium mespili. Several years back, this fungus spread through the once-popular red-tip plant (Photinia fraser), to the extent that this species is now rarely used.
An Indian hawthorn plant heavily affected with leaf spot fungus can be covered with round circles on the green leaves, eventually leading to plant death. Photo credit: Carrie Stevenson, UF IFAS Extension
Symptoms of leaf spot fungi include small, circular red spots on young leaves, which then expand into larger patches. On older leaves, the spots are gray in the middle with red/maroon borders. Eventually, leaves can drop and entire plants may defoliate and die. The disease typically spreads through rainwater or overhead irrigation.
To manage the disease, it is best to create space between a sick plant and a healthy one to allow better air circulation. This will allow leaves to dry off after rainfall events and prevent expansion of spores. Be sure not to overwater, prune, or fertilize shrubs that show signs of the disease, as this encourages growth—the fungus thrives particularly well on young, vigorously growing leaves.
For leaf spot problems that become difficult to manage with just cultural practices, fungicides containing chlorothalonil, myclobutanil, or propiconazole may be used. Always follow label instructions when using chemical management and apply in the spring or fall. In addition, dead or dying plants should be removed and replaced with cultivars showing resistance to Entomosporium leaf spot, including Eleanor Tabor, Indian Princess, Gulf Green, Betsy, Blueberry Muffin, Georgia Petite, Olivia, and Snow White.