by Julie McConnell | Jul 1, 2013
Blueberries
Have you tasted the great local blueberries available this season? Want to start your own Blueberry garden? Now that Blueberry harvest is in full swing in the Florida Panhandle, it is a good time to discuss blueberry culture.
Blueberry plants in garden centers lure us in with bell shaped flowers or especially if already setting fruit. Before you take one home, make sure your site is suitable. Doing your homework before you plant is important, but especially so when you want to grow a plant with specific cultural requirements such as blueberries. Blueberries require well-drained acidic soil that contains organic matter, a minimum of 4-5 hours of sunlight daily, and space away from competing roots. Chill hour requirements and bloom time vary by blueberry types.
Soil in the Florida Panhandle has a wide pH range (measure of acidity) and can vary greatly even within a half-acre site. Having your soil tested prior to planting is critical to growing blueberries successfully because it is very difficult to lower pH if your soil is higher than the target range. Blueberries need acidic soil (pH 4.2-5.5) to be able to use micro-elements in the soil such as iron and zinc. As the pH increases, these nutrients become less available to the plant even if they are present in the soil in adequate quantities. Nutrient deficiency leads to weak plants and loss of vigor. Plan to test your soil before you purchase plants to ensure your site has the ideal pH range, visit your local UF/IFAS County Extension Office to obtain a soil test kit. For more details about how soil pH affects your landscape, please see EDIS SL256: Soil pH and the Home Landscape or Garden.
Sandy soils commonly found in North Florida tend to be low in organic matter. Incorporating soil amendments directly into planting beds or using mulches that decompose (such as pinestraw or wood mulch) will help increase organic matter in your landscape. Peat moss or pine bark can be incorporated into beds planned for blueberries or pine bark can be used as mulch. Adding organic matter will help retain soil moisture, which is beneficial to blueberries that have shallow root systems.
Retaining soil moisture is valuable to blueberries, however, the site does need to drain well to a minimum depth of 18 inches. Areas that remain wet for long periods of time increase the risk of Phytophthora root rot damage. If an otherwise ideal site does not drain well, consider building a raised bed or changing the location.
Four to five hours a day is the minimum sunlight needed for good blueberry production. Make sure your sunny site is at least 20 feet from building foundations and competing tree roots. Blueberry plants can get large, over ten feet in height and width! Plan to give them room to grow; with pruning they can be maintained around 7’x7’.
There are two main types of blueberries that grow well in Florida: the southern highbush and rabbiteye. Among those types, there are specific cultivars with low chill requirements that perform better in Florida than in other southern states. Rabbiteye blueberries are recommended for areas north of Ocala, southern highbush for central and south Florida. When choosing cultivars, you need to plant at least two different cultivars within the same type (rabbiteye with rabbiteye) and make sure that bloom time overlaps so that cross pollination can take place.
Rabbiteye cultivars recommended for the Panhandle are:
Early season
• ‘Beckyblue’
• ‘Bonita’
• ‘Climax’
Mid- to late-season
• ‘Brightwell’
• ‘Powderblue’
• ‘Tifblue’
• ‘Woodard’
• ‘Chaucer’
• ‘Bluegem’
For more information about blueberry site preparation, selection, pest management, and care please see EDIS CIR1192 Blueberry Gardener’s Guide.
by | Jul 1, 2013
This summer parts of the Florida Panhandle have been blessed with ample rain, but coupled with high temperatures, this can be both a blessing and a curse.
Adequate moisture is critically important to landscape plants during hot weather, but too much rain or excessive watering also can bring problems. Wet soil combined with high temperatures can create stressful conditions for bedding plants, vegetables, shrubs and even trees – especially those just planted this year.
When the soil is saturated with water, pore spaces in the soil, which normally hold air, are filled with water. Since the roots of plants get the oxygen they need from the air in those spaces, the roots can literally drown in a soil that stays waterlogged over an extended period.
In turn, a sick root system leads to a sick plant. Plants in such situations often lose vigor, look wilted, turn yellow, are stunted and often die.
Symptoms of Root Rot on Azalea
Wet soil conditions also encourage fungus organisms that live in the soil to attack the roots or crown of a plant, thus causing rot. The crown is the area where the stem of a plant enters the soil. These disease organisms can cause die-back, inflict severe damage or even kill plants. Worse yet, once infection occurs, little can be done to help a plant affected by these disease organisms.
Plants with succulent stems such as impatiens and begonias, those that like cooler temperatures such as geraniums and dianthus and those that prefer drier, well-drained soils such as Indian Hawthorns are particularly susceptible.
Gardeners can take steps to help alleviate the situation. First , it is critical to adjust irrigation systems that are on automatic timers. Often seen are sprinklers unnecessarily watering at homes or businesses the day after or during a heavy rain simply because the timer turned them on. Turn off the automatic timer if the weather is wet, and turn the system on only when drier conditions occur.
Home Irrigation Timer
Beds should always be well mulched, at 2-4 inches, to control weeds and maintain soil moisture. If garden beds are staying too wet, however, the mulch can be pulled back from around plants or removed entirely to allow the soil to dry faster. Just make sure keep weeds are kept under control while the mulch is off.
Plants affected by wet soils or root rot may look wilted even though the soil is moist. A plant showing these symptoms immediately after a period of prolonged heavy rain may benefit from soil aeration in its root zone. Using a garden fork by driving the tines straight down into the soil and pulling straight out in numerous places around the plant is helpful. This provides air to the roots and encourages the soil to dry faster. Just be sure you don’t dig with the fork.
Gardening Fork
Fungal diseases that attack the foliage of many plants also are encouraged by rainy weather. Black spot on roses is prevalent even on fairly resistant varieties, and control is nearly impossible if it rains every afternoon. Cercospora leaf spot and Powdery mildew on crape myrtles can cause the leaves to turn yellow or red and drop off. The disease is not fatal, and the trees will recover without sprays, but flowering may be diminished.
Powdery Mildew on Crape Myrtle
Cercospora Leaf Spot on Crape Myrtle
Other pests such as snails and slugs thrive and reproduce rapidly during rainy weather. These pesky critters chew holes in the leaves and flowers of plants and are particularly fond of soft-leaved plants such as impatiens, begonias and hostas. Try not to let their populations get out of control. Note that Toads should be left alone because they feed on slugs. There also are numerous baits on the market that will help control snails and slugs. You can even place a bowl up to its rim in the ground and fill it half full of beer to attract and drown many snails and slugs.
Frequent rains can leach available nutrients from the soil in the landscape. Landscape plantings should be evaluated with this in mind and be fertilized, if needed. If possible, controlled release fertilizer should be used in this situation. Plants rapidly growing now such as lawn grasses, summer bedding plants and tropicals like ginger and hibiscus are especially vulnerable.
by Beth Bolles | Jun 17, 2013
There are a couple of possibilities for gardeners who are looking for something a little different than the old favorite French hydrangea. If you want to make your neighbor’s and gardening friends envious, consider adding one of the following selections to your garden.
The first to consider is the ‘Limelight’ hydrangea (Hydrangea paniculata) which is a hardy shrub and performs well in sunshine. New leaves emerge each spring and large greenish-white blooms emerge in the summer. Blooms may offer a color change into the fall, adding a delicate pink shade. This hydrangea should definitely be installed where it can be viewed and can grow 6-8 feet in height with a similar spread. Once established, it can be tolerant of some drought but will require moisture during extended dry periods.
If you have a garden with more dappled shade, the ‘Fuji Waterfall’ hydrangea is a good selection. This hydrangea will require a soil with more consistent moisture and will offer interesting lacecap blooms that appear to cascade over the dark green leaves. Growth will have a layered look with plants reaching about 3 to five feet in height.
For more information on newer selections of hydrangeas for our climate visit the University of Florida publication New Hydrangeas for North and Central Florida: Bigleaf and Mountain Hydrangeas
by | Jun 4, 2013
Proper watering can make the difference between life and death to newly planted lawns, trees, shrubs, bedding plants, vegetable transplants and ground covers during the summer.
Because their roots have not had time to grow out into the surrounding soil, these plants do not yet have well-established root systems. With their root systems still limited to a relatively small area of soil, they are especially vulnerable to drought stress.
Trees
The first summer after planting is the most critical time for newly planted trees, and proper watering plays a major role in whether or not they survive – or how well they survive. Here are some effective watering techniques for trees.
One good method is to turn a hose on trickle, lay the end on top of the ground within 6 inches of the trunk of the tree and let the water trickle for about 20 minutes to 30 minutes. Or build a 4-inch high levee out of soil around the edge of the area dug up to plant the tree. Fill this area with water and let it slowly seep into the root zone.
I’ve found one of the best methods is to use a heated metal skewer or ice pick to pierce five to 10 holes through the bottom of a 5-gallon paint bucket or similar container. Make all the holes on one side. Place the bucket next to the tree trunk with the holes closest to the trunk. Fill up the container, and the water will slowly seep through the holes, providing excellent irrigation. If you want, you can spray paint the outside of the bucket dark green to make it less noticeable.
Use any of these techniques during hot weather whenever seven to 10 days pass without substantial rainfall. Continue to water twice a week until a good rain occurs. Drought-stressed trees may experience wilting, leaf drop, yellow or brown leaves, scorched leaf edges or even death.
Shrubs
Newly planted shrubs will need to be monitored more carefully and watered more frequently than established shrubs. Water with soaker hoses or sprinklers left on long enough for the water to penetrate at least 4 to 6 inches into the soil.
Keep in mind that all of a newly planted shrub’s roots are in a small area – about the size of the pot the shrub was growing in before planting. This is especially true for shrubs planted after March, since they have had little time to grow roots into the surrounding soil. A shrub can use up all the water in its root ball and become drought stressed even though the soil in the bed outside of the root ball is moist. So when checking the soil moisture in the bed, always be sure to stick your fingers right around the shrubs themselves.
Lawns
Now is a great time to lay sod to install a new lawn or repair an established one. But keep in mind that newly laid sod needs special attention to watering.
Water newly laid sod for about 15 to 20 minutes every day for the first seven to 10 days. Then water for about 30 minutes every other day for another seven to 10 days. After that, irrigate the lawn thoroughly once or twice a week, as needed, to encourage the roots to grow deep into the soil.
Do not water every day for more than 10 days or you may encourage fungus diseases. And, of course, there is no need to water if adequate rainfall occurs.
Seeds
Water seeded areas (vegetable seeds, flower seeds or lawn seeds) lightly by hand or with sprinklers every day until the seeds germinate and start to grow. It is critical for the soil to stay moist during germination.
Once the seeds come up, water more thoroughly less often to encourage the roots to grow deep into the soil. As the seedlings become established, water normally as needed.
Containers
Watering plants in containers outside is a constant job during the summer. It is typical to water every day, even twice a day, when weather is hot and dry. Keep this in mind when considering how many outside container plants you can maintain.
How often you have to water container plants is influenced by temperature, pot size, the type of potting mix, the drought tolerance of a plant, whether a plant is in sun or shade and how pot bound a plant is. Plants need to be watered more frequently when it is hot, if the containers are small, if a light potting mix is used, when plants are in a sunny location and when plants are pot-bound. In addition, clay pots tend to dry out faster than plastic or glazed ceramic pots.
To reduce the amount of watering you have to do, use larger rather than smaller pots, choose a potting mix that retains more water (it must still be fast draining, however), repot pot-bound plants into larger containers, use plastic pots and, if practical, move the plants into somewhat shadier conditions.
Potting mixes will retain more water with the addition of hydrophilic polymers. These gelatin-like particles hold large amounts of water without creating a waterlogged soil condition. Look for these polymer products or potting mixes that contain them where garden supplies are sold.
by Julie McConnell | May 2, 2013
Hydrangeas
Bigleaf Hydrangea (Hydrangea macrophylla) are familiar faces in the southern shade garden. Although not originally from North America, they were introduced here over 200 years ago and perform well in the climate of the Florida Panhandle. Here are some quick tips about Bigleaf Hydranges.
- Hydrangeas prefer morning sun with afternoon shade or full shade and well-drained, moist soil
- The form is a mounding shrub that can have varying heights and widths, allow for a mature size on average of 6′ x 6′
- Hydrangeas have large green leaves that may be glossy or dull and are deciduous unless the winter is very mild
- There are two main flower types:mophead and lacecap
Lacecap Hydrangea
- Mophead flowers are rounded and usually composed of sterile flowers, with a few fertile flowers
- Lacecap flowers have sterile flowers on the outer edge of the circle, with fertile flowers in the center. When fertile flowers are fertilized they may turn a different color and the sterile flowers on the outer edge may invert themselves so they appear to be hanging down
- Flowers may be white, pink, purple, or blue; flower color is influenced by soil conditions and you may see multiple colors on the same plant!
Penny Mac Hydrangea
- Bigleaf hydrangeas generally bloom on old wood, however, there are some types that will also bloom on new wood and fall into either “free-flowering” or “everblooming” categories. Free-flowering have flower buds on the tips of branches (old wood) and develop flower buds up and down the stem that flower after terminal (tip) buds flower. Everblooming hydrangeas form flower buds on the tips of both old wood and new wood and can flower throughout the season.
- If soils are sandy and infertile, add organic matter before planting
- Water as needed, especially during establishment phase (typically first year or two). Expect hydrangeas to wilt during hot summer afternoons, as with any plant check the soil moisture before irrigating to avoid overwatering
- Avoid overhead irrigation, leaf spot diseases and powdery mildew are more prevalent when foliage is wet for extended periods
- Prune after flowering, but before August when shaping is neededFor more information about long flowering hydrangea varieties see “New Hydrangeas for North and Central Florida: Bigleaf and Mountain Hydrangeas”
To learn more about influencing flower color and general care of hydrangeas read “French Hydrangea for Gardens in North and Central Florida.”
by Eddie Powell | Feb 15, 2013
As spring approaches, many gardeners get out the pruning shears and prune everything in sight. That might not be the best course of action! Take a look at these tips for flowering landscape shrubs to learn more about pruning techniques that will maximize amount of bloom.
Why Prune?
• Control plant size or form
• Remove damage (mechanical, disease, etc.)
• Prevent potential damage (overlapping branches, poor crotch angles, diseases, etc.
• Stimulate new growth (rejuvenate old plants, fill bare areas, increase flowering, etc.)
When to prune:
• Corrective pruning due to injury or dead tissue should be done as soon as evident.
• Avoid pruning from August 15 until plants are dormant.
• Most pruning should be done during the dormant season or immediately after flowering.
Rules of thumb:
• The “May Rule”.
• May defined if the plant blooms before May 1, prune immediately after flowering has ended (flowers produced on old wood or last year’s growth: Azaleas, Forsythia, etc.)
• If the plant blooms after May 1, prune during the dormant season (flowers produced on new growth: Crape Myrtles, Lilac Chaste tree, etc.).
• As with any rule there are exceptions: Oak leaf Hydrangea.
General rules of Pruning:
• Local in affect (usually within 6” of cut).
• Cuts should be made ¼” above a bud or to a crotch (Lateral branch).
• Cuts should be made at angles.
Pruning Equipment: (Make sure blades are sharp)
• Hand Snips (for small branches)
• Loppers (branches > 0.75” in diameter)
• Pruning Saw (limbs > 1.5” in diameter)
• Shears (for a more formal look)
• Pruning Knife (for clean-up)
Safe Pruning Principles:
• Keep equipment clean and in good repair.
• Appropriate, properly fitted safety equipment for job (eye and ear protection, no loose fitting clothes, etc.)
• Keep equipment within your control zone. Don’t over extend, know the limitations of your equipment and yourself.
• Know your surroundings (overhead utilities, other workers, etc.).
• Be able to identify Poison Ivy, Poison Oak, and other skin irritants.
Quick Tips to Remember:
• Pruning: Remove dead wood and seed pods annually during the dormant season.
• Size control should be done by cultivar selection, not by pruning.
• To promote a second set of flowers, prune away faded or spent flowers throughout the season.
For more information, click here for a UF / IFAS Extension publication on proper pruning techniques.
If you have any questions contact your local county extension agent.
by Eddie Powell – Walton County Extension Horticulture Agent
