Fleshy distortions are appearing on some azaleas this time of year. What is responsible for this? A fungus, Exobasidium vaccinia, likes our cool, wet spring weather and infects azalea leaves and flower petals. This disease likes a cool, wet, shady and protected environment.
Azalea gall. Photo credit: Mary Derrick, UF/IFAS Extension.
The infection causes the plant to form large, fleshy, distorted tissues known as galls. The galls produce a white powdery coating that is capable of producing more spores that will continue to cause new infections if left on the bush. The gall will eventually turn dry and brown and fall to the ground. Sometimes there are only a few leaves infected or there may be quite a few on a bush.
Not to worry – this is not likely to cause significant harm to your azalea. The best plan of action is to remove the galls as soon as possible and dispose of them in the trash or burn them to prevent reinfection of your plants. Avoid any irrigation that sprays water onto the leaf surfaces as the moisture creates a favorable environment for disease. Once you see this gall forming, there is no chemical control that is effective.
For more information on caring for your azalea:
Azaleas at a Glance
Bees have been disappearing at an alarming rate and continue to vanish without a trace. Why should anyone care? Well, they matter a lot more than most people think. Bees are the overwhelmingly dominant pollinator for most food crops. Native bees in the United States are responsible for pollinating over $15 billion worth of agricultural commodities annually. However, native bee populations are in decline due to habitat loss. At the same time, managed colonies of European honey bees have suffered a 50% decline over the past few decades. Numerous other pollinating insects are facing the same fate.
European honey bee. Photo credit: UF/IFAS.
As the spring planting season is upon us, it’s exciting to think about all the wonderful produce we will have this summer. But, without pollinators many of these crops would not be available. The majority of fruit and vegetable food sources we eat are dependent on insect pollinators. One of every three bites of food Americans consume comes from a plant visited by bees or other pollinators.
As declining numbers of farmers work to meets the need of increasing populations, they are forced to make choices on alternative to chemicals for pest control. “Good bug blends” of flowers can help attract pollinators as well as beneficial insects that suppress harmful pests. Establishment of these meadows can be done on a small or large scale and in any habitat. One approach to “bring back the pollinators” is to intercrop with blooming plants that attract insects. Selecting a diversity of plants with different flower sizes, shapes and colors, as well as various plant heights and growth habits, will encourage the greatest numbers of pollinators. It is important to provide a continuous source of pollen and nectar throughout the growing season. At minimum, strive for three species to be blooming at any one time; the greater the diversity the better.
To enhance the garden, choose flowering plants that also provide shelter for beneficial insects. Many companion plants are suitable habitat for predators and parasitoids. Research in Florida has demonstrated that predatory minute pirate bugs can build to high numbers in sunflowers. The favorite food of minute pirate bugs is Western flower thrips. So, planting sunflowers on the perimeter of vegetable crops, such as peppers, can greatly reduce the damage caused by the thrips. Similar results were found with the planting of sorghum to attract beneficial mites and intercropping with buckwheat to house syrphid flies and parasitoid wasps. The garden vegetables experienced fewer spider mite, whitefly and aphid problems. Crimson clover, Hairy vetch and cosmos are other annual seed crops that can aid in attracting pollinators and harboring beneficial insects.
Blue Mistflower. Photo Credit Mary Derrick, UF / IFAS Extension.
Insectary meadows can be created in the landscape and along roadways, not just in the garden. For more permanently planted areas, native wildflowers, grasses and woody plants serve as larval host plants for butterflies, and also provide nesting and overwintering sites for bumble bees, predacious beetles and other beneficial insects. Native perennial wildflowers such as blanketflower, tickseed, black-eyed Susan, partridge pea, narrowleaf sunflower, milkweed, beebalm, goldenrod and silkgrass can be installed in the spring as potted plants or seeded in the fall. Seeds require exposure to cold temperatures and damp conditions before germination can occur. In Florida, the best time is November to February.
Though grasses do not offer nectar or high-quality pollen, it is often useful to include at least one native bunch grass or sedge. Short, clump-forming grasses are preferable to large, spreading grasses. Hedgerow planting of woody species is a way to provide winter-blooming plants vital for supporting pollinators. Woody plants and grasses provide more than forage for pollinators, as many native bee species nest in the stems of plants or in the undisturbed ground underneath plantings. Suitable grasses include: beaked panicgrass, purple lovegrass, Muhly grass, broomsedge,little bluestem, wiregrass and toothache grass. Favored woody species that make good “beetle banks” include: fetterbush, American beautyberry, saw palmetto, Chickasaw plum, red maple, sparkleberry, Dahoon holly, redbud, blackgum, magnolia, buttonwood and sourwood.
Regardless of whether the objective is to establish herbaceous or woody vegetation, the time and effort spent on eradicating undesirable plants prior to planting will result in higher success rates in establishing the targeted plant community. Choose level, open sites that receive full sunlight and have limited weed populations. If perennial weeds are a problem, the use of herbicides that have no soil residual (e.g. glyphosate) may be necessary.
For more information on establishing planting for pollinators visit: www.xerces.org/pollinator.
UF/IFAS Photo: Tyler Jones.
Most people know that an attractive landscape adds to the value of a home. For most of us, the landscape also represents a hefty investment of money, time and work so it’s important to know enough about landscape design to do the job right.
An important step in developing an attractive landscape is spacing plant materials correctly. Plants should be placed in the landscape in relation to each other, and with some understanding of their ultimate height, spread, and growth rate. However, the endless variety of plant sizes and shapes can easily complicate this matter for the home gardener.
How the plant is used in the landscape will determine its shape to a large extent. For example, if a plant is part of a hedge row, it should be placed close to the other plants so that in a few years, all of them grow together. If you want to retain the individual shape of each plant space the plants further apart.
Spacing trees correctly is very important as trees are the largest and most permanent of all landscape materials. Here are a few examples of some ways to use trees effectively around the home:
- Pine trees look very good as a tall background screen in the landscape. To have the trees work as a screen, plant them eight to twelve feet apart measuring from the center of one tree to the center of the next.
- Mass planting of dogwood, redbud and crape myrtle make brilliant assets to your landscape. If these trees are spaced about 12 to 15 feet apart, the top foliage should meet in a few years. When these trees are in bloom, the mass plantings will enhance their show of flowers.
- An oak tree planted on the west side of your lot will provide shade for your home, the tree should be planted about thirty feet from side of the house, to prevent tree limbs from eventually crowding the house.
As you can see, it’s important to learn as much as possible about trees you select for your landscape. In spite of the few examples given you, there is no single standard recommendation on spacing trees in the home landscape. This is because most of the popular landscape trees can range from 10 to 100 feet in height, and vary as much in spread. Specialists recommend that the minimum spacing for landscape trees should be one half of the spread of the tree’s mature canopy from other trees, from walls and other existing structures. But even this minimum spacing may vary among different varieties of the same species. For specific spacing requirements for the tree you are interested in check with your local County Extension Office.
With the over abundance of rainfall the western panhandle has seen in recent weeks, tomato gardeners need to be aware of foliar diseases that could appear. Tomato leaves are an ideal host when moisture is present on the leaf surface. There are several of these diseases that, if not managed, can destroy the garden.
Advanced symptoms of Early Blight (Photo Credit: UF/IFAS U-Scout website)
Early Blight is a fungal disease that can affect tomato leaves and fruit. The disease is most prominent when temperatures are 80°F and excess moisture is present from rain or irrigation. The most classic system is the presence of leaf lesions that are approximately 1/2 inch in diameter.
Bacterial Spot on a Tomato leaf (Photo Credit: Hank Dankers, From U-Scout)
Bacterial Spot can also cause problems for Florida tomato gardeners in rainy and high temperature periods. Generally the symptoms are darkened circular lesions on the leaves and fruit. Sometimes bacterial spot can be confused with other leaf lesion diseases. The bacterial spot will ooze when cut where as fungal type lesions will not.
How to prevent foliar diseases in tomato:
- Always start with disease free seed and transplants.
- Irrigate early in the day to minimize the time the leaves stay wet. Use drip irrigation when possible.
- Remove blighted leaves when the garden is dry. This technique should not be relied on exclusively.
- Remove and destroy crop residue at the end of the growing season. If not removed, it can become a breeding ground for disease next year.
- Rotate to different plant families that are not affected by the same diseases.
- Spray protective fungicides such as Mancozeb, Copper, and Chlorothalonil (for example sold as Daconil) when the conditions are right for disease (higher temperatures, excessive moisture, and rainfall).
If you have questions about these diseases or other tomato diseases, please comment below or call your local UF/IFAS Extension Agent.
In all North Florida Counties, blueberry jam, blueberry cobbler and fresh blueberries seem to be a staple. This is because there are many home gardeners are able to consistently grow a top quality product. This year blueberries are very large already on plants throughout the panhandle! The increased size may be indicating earlier maturity than in the previous few years.
Backyard gardeners also desire to grow the same type of blueberries grown by local farmers but sometimes struggle to find the correct type. Vaccinium ashei (commonly known as rabbit-eye blueberry) is a species of blueberry native to Florida and adapted to the late frosts we sometimes get in Northwest Florida during the months of February and March. It is recommended that this species be grown in this area, not its sister species the Southern Highbush, Vaccinium darrowii. There are several dwarf cultivars of Vaccinium darrowii that can be used to great effect in the landscape, but will not produce a noticeable crop of fruit most years.
The rabbit-eye blueberry is a deciduous shrub growing to 3 to 6 feet tall and with up to a 3 foot spread. The leaves start out red-bronze that turn dark-green when fully developed. It has small, white bell-shaped flowers. It produces 5 mm diameter fruit, dark blue to black, with a pale gray wax coating.
Rabbet-eyes are self-infertile, meaning that they must have two or more varieties to pollinate each other. Therefore it is advisable to plant two or more cultivars close together to ensure complete fruit set. Recommended cultivars for our area include, ‘Brightwell’,’ Climax’, ‘Beckyblue’, ‘Tif-Blue’, Powderblue, ‘Woodard’, ‘Chaucer’ and ‘Bluegem’. Old, local plants can be found in gardens and in the woods, due to the fact that the WPA planted them under pines in the 1930s. These can easily be propagated by cuttings or by nicking and burying a lax stem under soil for a few month. Once the stem forms roots, it can be severed from the mother plant and transplanted.
Blueberries grow best on acid soil at a pH of 4.0 to 5.2. Few pests and diseases bother them, with the exception of scale, whitefly and mealybug. These are controlled with a combination of dormant oil sprays, and insecticidal soap.
Blueberries enjoy soil rich in organic matter and benefit to liberal applications of pine bark mulch. Their roots are fairly weak and should not be planted near turf or other weeds which may out-compete them in the race for water and nutrients. Mulching eliminates this grass and weed competition. In soil where organic matter is very low, such as in coastal sand hills, gardeners should grow blueberries in 2 foot deep trenches filled with rotting pine bark. Blueberries enjoy being spoon fed fertilizer, since heavy fertilizer doses stop fruit set and may damage fragile root systems.
When planting, it is advisable to not include fertilizer in the planting hole. “Blueberry Special” fertilizer mixes are available which are made up of ammoniacal or urea based nitrogen sources, with an analysis of 12-4-8 and 2% magnesium. This mixture is available at many local feed and garden stores. New plants should get one ounce per application in April, June, August and October. 2 year plants should receive 2 ounces per application and older plants should receive 3 ounces per application. Fertilizer should be spread in a circle 2-4 feet in diameter around the plant for optimal root uptake. It does no good to just pour the fertilizer at the plant base, since feeder root are further out from the plant.
Feel free to contact your UF IFAS extension agent for more information about blueberry cultivation