by | Sep 16, 2013
While the recently passed Labor Day is often is touted as the traditional “end of summer,” according to the calendar, fall officially will begin with the fall equinox on Sept. 22nd at 4:44 EDT. In north Florida, however, we know good and well that our summer season extends a good bit longer.
Still, even if it just feels right, there is something going on now. When you walk out in the morning, the air feels just a bit more comfortable. The days are getting shorter, and that is beginning to have an effect. Perhaps it’s just wishful thinking, but if you squint just right, you can ALMOST see the end of our long and brutally hot summer.
The word “fall” commonly conjures up images of harvest, falling leaves, the end of the growing season and the beginning of dormancy leading into winter. For gardeners in North Florida, however, the traditional fall period is not a time of winding things down in the garden or even landscape but of revival and renewed effort. It’s a time when we finally can get back into outside and enjoy ourselves as the debilitating heat of summer starts to lose its grip on the weather.
For the next couple of months we will experience a gradual shift to milder weather. There will be cool spells followed by decidedly hot, summer-like weather, but as we move into late October, cooler weather will begin to dominate the scene. Not until mid-to late November do we generally experience the nippy cold weather and changing leaves that tell us, yes, indeed, fall has finally arrived.
One thing you that you might notice that may surprise you may be an increase of vigor in your warm-season bedding plants in September. Even heat-tolerant flowers do not always look their best in August.
Since shorter days mean fewer hours of intense heat, even though the daytime highs may stay about the same, plants begin to experience less stress. This encourages a “second wind”, if you will, in the flower garden that may last well into October or early November. Given this, consider cutting back some of your summer bedding plants and flowers that have grown tall and leggy over the just passed long growing season. This should be done in by the second or third week in September at the latest – and generally involves cutting plants back about one-third to one-half their height.
While you’re at it, it might be a good idea to impose some order on those overgrown flower beds. In addition to cutting back, groom plantings to remove dead flowers and unattractive foliage.
If plants are leaning or have fallen over onto nearby neighbors, prop them up or stake them so they will stand upright. Just about every year at this time I find the remains of some unfortunate plant that was overwhelmed when larger, more vigorous, nearby plants leaned over it.
In addition, if you haven’t done so already, gently trim your everblooming rose bushes, including such popular groups as Hybrid Teas, Grandifloras, Floribundas, Miniatures, Teas, Polyanthas, Bourbons, Chinas and English roses, to name just a few. This should be a very light trimming, little more than deadheading, since the main pruning of everblooming types is done in mid February. On the other hand, keep in mind that many old-fashioned climbers, ramblers, Lady Banks roses and some bush roses that bloom heavily only in spring to early summer will bloom next year on the growth they made this summer. Those roses should not be cut back at all now.
Even though you can get back into the garden to work, it is still too early to plant hardy trees, shrubs, ground covers and vines in the landscape. Temperatures in the 80s and 90s likely will be common in September, and that is still too stressful for new plantings. Wait at least until the cooler weather of October, since the ideal planting season for hardy trees, shrubs and ground covers really is from November through February. And for those that like to plant pecan trees, these are often done in bare root when the trunk of the tree is about the size of a pencil. These MUST be done when completely dormant or you will not have a successful outcome.
While Fall is for Planting, be sure that you don’t start too early!
Keep in mind that even though they will begin to show up in area nurseries this month, it is also is too early to plant cool-season bedding plants. Even if you have an area where your summer flowers have finished and have been removed, it is still too hot to plant most cool-season bedding plants. Instead mulch the area now and wait until the reliably cooler weather of October or November before you plant your bedding plants.
Spring-flowering bulbs, such as tulips and daffodils, become available this month, but there is absolutely no hurry to plant them. Purchase them if you like while the selection is good, but wait to plant your spring flowering bulbs from mid-October through early December.
Keep in mind that insects and diseases stay active through the fall, so continue to control any pest problems with timely applications of the proper material. In addition, don’t forget, now as always, water well during dry periods, and you should have an excellent crop of flowers in October through November.
I guess if you think about it, it’s best to say that Labor Day really marks that time in north Florida when we can anticipate the soon-to-arrive milder weather and look forward to enjoying the delights of gardening over the next few months. When the fall equinox arrives later this month, don’t get carried away. For us, summer will still be lingering for a little while longer.
by Sheila Dunning | Aug 23, 2013
At the halfway point through 2013, cumulative rainfall amounts for the calendar year were near normal, on average, across the Northwest Florida Water Management District. January, March and May were rather dry. Yet, February, April and June had an abundance of rain. Then, in early July, an unusual persistent mass of moist tropical air brought intense rainfall to the Florida Panhandle. Instead of fireworks on the Fourth of July, most places had record rain. The flooding resulted in washed out roads, drown peanuts and exploding watermelons.
Yet, many landscape sprinkler systems were still running. One has to ask, “Where are all the rain shut-off devices?”. Florida is one of just a few states with a rain sensor statute. Since May 1991, new installations of irrigation systems have been required to include a rain shut-off device. However, no wording was included to cover installation or maintenance. The 2010 statute change now states the following: “Any person who operates an automatic landscape system shall properly install, maintain and operate technology that inhibits or interrupts operation of the system during periods of sufficient moisture.” (Florida Statute 373.62).
Thus, ALL automatic landscape irrigation systems require rain sensors, or other shut-off devices such as soil moisture sensor irrigation controllers. No “grandfather clause” was included for existing systems. Regardless of when it was installed, every sprinkler system must have an operational rain shut-off device. Irrigation contractors can be fined for working on a system without checking out and/or connecting a device.
Moisture sensing technology conserves water, saves money, reduces wear on irrigation system components, reduces disease and helps protect water resources from runoff. Previous research has shown that homeowners using in-ground, automatic irrigation systems, typically in Florida, apply 47% more water for landscape irrigation than homeowners without automatic irrigation systems. This over-irrigation is largely due to a “set it and forget it” mentality despite seasonal fluctuations in plant water needs. If the water costs and the amount of water applied per watering cycle are known, it is easy to calculate how much money is being saved each time the sensor interrupts the program. For example, if a system irrigates ½ acre of turf and is set to deliver ½ inch of water to each zone, approximately 13,576 gallons of water will be used during each watering event. If the cost of the water is $2.00 per thousand gallons, every time the sprinkler system comes on the water bill will be $27.15. A significant amount of money and water can be saved by maintaining a rain shut-off device.
Irrigation is common in Florida landscapes because of sporadic rainfall and the low water holding capacity of sandy soils. Water conservation is a growing issue due to increased demands from a growing population. The least expensive and most common rain sensor device is the expansion disk rain shut-off. Expanding cork disks trigger a pressure switch. The expansion space can be easily adjusted by rotation of the disk cover to a predetermined amount of rain required to trigger the switch. The amount of rain that will interrupt the irrigation system is marked on the adjustment cap. A rain sensor must be mounted where it will be exposed to unobstructed rainfall, typically installed near the roofline on the side of a building.
Irrigation control technology that improves water application efficiency is now available. Soil moisture sensors (SMS) can reduce the number of unnecessary irrigation events. Most soil moisture sensors are designed to estimate soil volumetric water content based on the soil’s ability to transmit electricity, which increases as the water content of the soil increases. Bypass type soil moisture irrigation controllers use water content information from the sensor to either allow or bypass scheduled irrigation cycles on the irrigation timer. Another type of control technique with SMS devices is “on-demand” where the controller initiates irrigation at a low threshold and terminates irrigation at a high threshold. A single sensor can be used to control the irrigation for many zones or multiple sensors can be used to irrigate individual zones. In the case of one sensor for several zones, the zone that is normally the driest, or most in need of irrigation, is selected for placement of the sensor in order to ensure adequate irrigation in all zones. Sensors should be buried in the root zone of the plants to be irrigated. For turfgrass, the sensor should typically be buried at about three inches deep. The placement of SMS should be at least 5 feet from hard surfaces and sprinkler heads. The sensor needs to be calibrated and/or the soil water content threshold needs to be selected.
The amount of water that can be saved using rain shut-off devices is substantial. Since the end of March, groundwater levels in the coastal Floridan aquifer shows a slight decline, primarily due to increased pumping from higher seasonal populations during the spring and summer months. In the western panhandle, groundwater levels in the Sand and Gravel aquifer are below normal, which indicates that infiltrating recharge from the above normal rainfall has yet to reach the water table. Remember that every drop that hits the ground will be picking up pollutants as it flows to our groundwater. Nonpoint source pollution is the leading cause of water quality problems. These pollutants have harmful effects on drinking water supplies, recreation, fisheries and wildlife.
By only irrigating when the soil needs it, you are also preventing contamination of drinking water.
by Taylor Vandiver | Jul 15, 2013
Turfgrass, like all plants, requires water for growth and survival. With the weather we’ve been having lately, watering your lawn is probably the last thing on your mind.
Footprints in turfgrass are a common symptom of drought stress. They are the result of a loss in turgor pressure, due to lack of water, in plant tissue.
However, without sufficient rainfall, water to home lawns will need to be supplemented with irrigation. The most efficient way to irrigate or water your lawn is to apply water only when the lawn starts to show signs of drought stress from lack of moisture.
A few signs associated with drought stress include the changing of turfgrass color from green to a bluish-gray, or white cast. Another sign could be “footprints” on the lawn. If walking across a lawn late in the afternoon causes footprints to be left behind, the lawn may need watering. When feet compress the leaf blades of the turfgrass, the low water levels in the plant tissue prevent the leaf blades from recovering, or “springing” back up, after being pushed down. If the footprints remain for an extended period of time, water the lawn to prevent the turfgrass from turning brown and becoming dormant. The visual condition of the turfgrass can also be used to evaluate drought stress. Turfgrass blades respond to drought stress by folding, rolling, and/or wilting.
A recommended application of ½ to ¾ inch of water can be applied when your turfgrass begins to show the drought stress symptoms discussed previously. Once this amount of water is applied, do not apply again until drought is noticeable. If it rains, like it has been lately, hold off on irrigating until visible drought stress symptoms appear.
Irrigation frequency can vary based on grass species, rainfall amounts, soil type and amount of compaction, shade presence, location, etc. There is a fine line between under and over watering a lawn. Over watering can cause problems such as poor root growth and susceptibility to disease. Over watering can also increase the presence of weed species. When watering, avoid applying water to the point of runoff. Allow the water to soak into the lawn and soil. The optimal time of day to water lawn grass is during the early morning hours. If irrigation is done during the day that water is being lost to higher evaporation rates. Watering in late afternoon or late morning may be detrimental if it extends the time the lawn is naturally wet from dew. This extended “dew period” may increase disease presence in turf.
Automated irrigation systems are convenient, but can have flaws. Always check to make sure your system is working properly and is applying the correct amount of water. However, if significant rainfall has fallen for the week, the automated timed irrigation systems can be turned off so water is not wasted.
Once turf has been watered, it should not be watered again until similar drought stress symptoms are observed. It is never suggested to water your lawn every day, unless it is in the establishment phase or renovations are occuring. Proper watering techniques are key to creating a happy and healthy lawn.
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.
