by Julie McConnell | Sep 9, 2013
Fertilizer Spreader: Image Courtesy UF / IFAS Extension FYN Program
Although temperatures are still hovering around 90° F, the last fall fertilization date is approaching quickly. Mid-September is the
deadline for applying fertilizer to warm season turf-grasses and landscape ornamental plants for the year. Why is September 15 the cutoff date? In North Florida, our estimated first frost date is November 15. When fertilizer is applied the nutrients encourage new growth that typically takes about 6-8 weeks to become “hardened off” and able to tolerate low or freezing temperatures. So, simply backtracking on the calendar gives you an idea of when to make the last application of fertilizer (if needed).
If September 15 is at the end of our warm season feeding schedule, the next question should be “when should I fertilize in the spring?” Although Northwest Florida’s average last frost date is listed as March 15, UF/IFAS Turf Specialist Dr. Bryan Unruh does not recommend fertilizing before April 15 in the panhandle. There are two main reasons for this later date. One is that the March 15 last frost date is an estimate, many times cold weather follows a warming trend in late winter/early spring. During April of this year warm weather was followed by cool temperatures with cold winds that caused landscape plant damage. If fertilizer was applied before this weather arrived, some cold damage may have been evident this spring in affected landscapes. The second reason is that if fertilizer is applied to turf or plants that are not actively growing and using those nutrients, it may leach out of our sandy soils. Nutrients do not wait for plants to use them; they can be washed out and become a source of nonpoint source pollution.
To read more tips on fertilizing visit EDIS ENH1174 “The Lawn Fertilizer Toolbox”
by Julie McConnell | Aug 5, 2013
Chamberbitter
Above average rainfall this summer has supplied water to more than just our landscapes, weeds are benefiting and flourishing as well.
Just as with any other landscape pest, proper weed control starts with accurate identification and knowledge about the life cycle of the weed.
When weeds are low in number, mechanical control (pulling, mowing) is a good start. If weed population continues to increase and herbicide options are considered, several questions need to be answered before product application.
Questions you need to ask yourself about your weed and site:
- What weed(s) are you trying to control?
o Be sure you know what the name of the weed is so that you can find it on your product label “weeds controlled” list; if you need help with identification contact your local county extension office
- What is your site?
o Lawn – specific turfgrass is important, what is safe to use on one type may kill another
o Ornamental beds – again note specific plants near your treatment area in case of sensitivity
o Water bodies – some herbicides are not labeled for use within a given distance of water; if the weed is in or around the water only use herbicides listed for aquatic weed control
- What is the life cycle of your weed?
o Annual – one season life cycle, summer annuals complete their life cycle between spring and fall; winter annuals are active between fall and spring
o Biennial – two growing season life cycle
o Perennial – plant lives for three or more years
- What category does your weed fall into?
o Grasses – one seed leaf as it emerges from the soil; hollow, rounded, stems with nodes, parallel veins in true leaves; examples are crabgrass, dallisgrass, cogongrass, torpedograss
o Broadleaves – have two seed leaves and true leaves have net-like veins and usually have showy flowers; examples are lespedeza, dollarweed, clover, chickweed, henbit, florida betony
o Sedges/Rushes – sedges have solid triangular stems; rushes have round stems; both like moist or wet habitat; examples are purple nutsedge, yellow nutsedge, beak rush
Dollarweed: Image Credit Edis ENH1128
Basic information about herbicide categories:
For more information read EDIS Publication “Weed Management in Home Lawns”
by Julie McConnell | Jul 22, 2013
When you contact your local extension office for pest control recommendations you will likely hear “follow the label” over and over again. So, why do we emphasize the pesticide label so strongly when talking to both homeowners and landscape professionals?
There are many important reasons why you should always read and follow label instructions.
- The Label is the Law – using a pesticide in a manner that is inconsistent with the label is a violation of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Using a product inconsistent with the label includes, but is not limited to: rate of application, use on site not labeled for control, use on plants/lawns not labeled, frequency of application, method of application, distance from water sources, etc.
- Safety of Humans – using a product incorrectly can cause harm or even lead to death
- Safety to Non-target Organisms – this includes non-target insects, reptiles, birds, fish, mammals, and plants which can lead to negative impact on environment and economy
- Effectiveness of Product – millions of dollars are spent to figure out the most effective way a product works best, follow their instructions! (remember the manufacturer wants the product to be effective so that you’ll recommend to others and buy it again)
- Increased Resistance Decreases Control – improper application and a failure to rotate products as part of an integrated pest management program can increase likelihood of resistant pest populations
Before shopping for any pesticides, do some research:
- Has the pest been identified properly? What life cycle stage is the pest at? Most pesticides have different levels of efficacy depending on life cycle of target. For example, glyphosate works best on young plants that have not yet flowered. Your local extension office can help with identification and timing of control methods
- Can you control the pest with cultural practices such dethatching, irrigation, fertilizer, or mowing height changes? Start with the least toxic method of control and only work up if ineffective
- Read the label before you buy to be sure that it is labeled for your plant /lawn, target pest. The label will also tell you what equipment you’ll need to mix and apply and safety equipment. If product is not ready to use, be sure you can follow mixing and application procedures safely
- Are there particular environmental precautionary statements that are relevant to your site?
- How much do you need? Have you measured the area for treatment? Just as you don’t want to make multiple trips to the store, you also do not want a lot of excess chemicals on hand. They have to be stored or disposed of according to label instructions, too
For more information about pesticide labels read EDIS PI-34 Interpreting Pesticide Label Wording.
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 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.”
