Summer Irrigation Tips

July’s hot summer weather has given way to August’s 31 days of what will likely be temperatures and humidity equally elevated and intense. Wishes for November’s cooler thermometer reading are already creeping into daily conversations. The lawns and gardens in Wakulla County have rains as a mitigating factor to counteract the wilting potential of normal to excessive temperature readings. Unfortunately the arrival of water from above is not on a set or easily predictable schedule.

Traditionally, summer is the wettest season in Florida, with more than half of the annual rainfall occurring during the June to September “wet season”. Florida’s highest average annual rainfall occurs in the Panhandle with averages exceeding 60 inches per year. The Pensacola and Tallahassee weather stations are listed among the ten “wettest” stations in the nation. Still, this pattern of seasonal precipitation can vary greatly between locations, years and even days.  This variability often results in the need to water the lawn, landscape and garden. By following a few guidelines, you can produce the best results for plants under stress and conserve a vital and limited resource.

It is most efficient to apply water between 5:00 a.m. and 10:00 a.m. for several reasons. Only water that is in contact with roots can be absorbed by the plant. If water is applied after 10:00 a.m., a substantial portion of it will evaporate before it reaches the roots; more will then need to be applied and this resource’s productivity will be reduced. Never water late in the afternoon as evaporation will still be a problem, and wet turf and plants will invite a variety of fungal diseases to flourish as night settles.

Photo Courtesy: Les Harrison, UF/IFAS Wakulla County Extension

In the case of landscapes and gardens, water should be applied only when the moisture in the root zone system has been depleted to an unacceptable level, usually by 1/2 to 2/3 of the stored soil-water. There are several ways to determine when the soil-water reservoir has been depleted beyond an acceptable level.  The simplest method is a visual inspection of the turf or plants. Common symptoms of water stress include leaf color changes to a bluish-gray tint, footprints which linger long after being pressed into the grass and curled or folded leaf blades. Be sure the sprinklers are delivering water to the target area as water which misses the soil and is applied to hard surfaces such as driveways and sidewalks will be wasted. It also may pose an environmental problem in the form of runoff.  Surface runoff that flows past the landscape will usually reach streams, ponds, or the Gulf of Mexico. If it picks up pollutants along the way, they too will reach the surface water bodies. 

Over watering can be just as damaging as too little water. Excessive irrigation water can infiltrate the ground and reach groundwater aquifers. This issue is complicated when groundwater runs close to the surface. Excessive nutrients or pollutants can be discharged into surface bodies or move vertically into the deeper land layers.  The connected springs and sinkholes in Wakulla County make the movement of surface water a common concern.  Responsible and efficient irrigation will have positive effects far beyond the front yard.

To learn more about the effective use of water in Wakulla County’s landscapes, contact your UF/IFAS Wakulla Extension Office at 850-926-3931 or http://wakulla.ifas.ufl.edu/

Rain Gardens – A Solution for Runoff

Rain Gardens – A Solution for Runoff

This rain garden used stone for a berm and muhly grass as a decorative and functional plant. Photo credit, Jerry Patee

Tropical Storm Cindy’s early arrival soaked northwest Florida this month, followed by even more heavy rain. Homes in low areas and along the rivers flooded and suffered extensive damage. That being said, we are just entering our summer “rainy season,” so it may be wise to spend extra time thinking about adjusting your landscape to handle our typically heavy annual rainfall.

For example, if you have an area in your yard where water always runs after a storm (even a mild one) and washes out your property, you may want to consider a rain garden for that spot. Rain gardens are designed to temporarily hold rainwater and allow it to soak into the ground. However, they are quite different aesthetically from stormwater ponds, because they are planted with water-tolerant trees, shrubs, groundcovers and flowers to provide an attractive alternative to the eroding gully that once inhabited the area! Rain gardens are not “created wetlands,” but landscaped beds that can handle both wet and drier conditions. Many of the plants best suited for rain gardens are also attractive to wildlife, adding another element of beauty to the landscape.

A perfect spot for a rain garden might be downhill from a rain gutter, an area notorious for excess water and erosion. To build a rain garden, the rainwater leaving a particular part of the property (or rooftop), is directed into a gently sloping, 4”-8” deep depression in the ground, the back and sides of which are supported by a berm of earth. The rain garden serves as a catch basin for the water and is usually shaped like a semi-circle. The width of the rain garden depends on the slope and particular site conditions in each yard. Within the area, native plants are placed into loose, sandy soil and mulched.   Care should be taken to prevent the garden from having a very deep end where water pools, rather allowing water to spread evenly throughout the basin.

This larger rain garden, or bioretention area, functions as stormwater treatment for a large parking lot in North Carolina. Photo credit: Carrie Stevenson, UF / IFAS Extension

Besides reducing a problematic area of the lawn, a rain garden can play an important role in improving water quality. With increasing populations come more pavement, roads, and rooftops, which do almost nothing to absorb or treat stormwater, contributing to the problem. Vegetation and soil do a much better job at handling stormwater. Excess sediment, which can fill in streams and bays, and chemicals from fertilizers and pesticides are just some of the pollutants treated within a rain garden via the natural growth processes of the plants.

A handful of well-known plants that work great in rain gardens include: Louisiana iris, cinnamon fern, buttonbush, Virginia willow, black-eyed Susan, swamp lily, tulip poplar, oakleaf hydrangea, wax myrtle, Florida azalea, river birch, holly, and Southern magnolia. For a complete list of rain garden plants appropriate for our area, visit the “Rain Garden” section of Tallahassee’s “Think about Personal Pollution” website.

For design specifications on building a rain garden, visit the UF Green Building site or contact your local UF IFAS County Extension office.

2015: International Year of Soils

2015: International Year of Soils

Dirt, earth, humus, terra firma, soil—no matter what you call it, the ground below us is one of the most important substances on, well, Earth. As children, most of us stomped in mud puddles, dug holes, and played in sand boxes—the tactile experience of moving dirt around seems to appeal to humans innately. Just last weekend a local charity raised thousands of dollars by setting up an obstacle course for adults (and kids) called the “Mud Run,” with participants exiting the race completely covered in mud.

Kids have an innate appreciation for soil! Photo credit: Carrie Stevenson

Kids have an innate appreciation for soil!     Photo credit: Carrie Stevenson

Despite how much fun it can be to play in, the humble soil often gets overlooked. Mixtures of clay, sand, and loam seem less exciting when competing for attention with more charismatic natural phenomena such as colorful flowering plants or powerful top predator animals. Partially because of this status, soil scientists and agronomists declared 2015 the “International Year of Soils” with the goal of educating the general public on soil’s importance.

While most of us don’t think about soil on a regular basis, it is the literal foundation for producing healthy food and much of our clothing, along with fuel sources and many medicinal products. Without the small organisms and insects living in the soil to break things down, everything that ever died could still be slowly decaying on the surface of the earth. Soil is the primary player in recycling and making crucial nutrients such as phosphorus, nitrogen, and potassium available to plants. If you’ve ever tried to grow vegetables in the Panhandle, you know the high sand content and low nutrient levels of many of our native soils leave much to be desired. Gardeners know that a mix of organic materials is necessary to give soil enough structure, water-holding capacity, and nutrient sources to provide plant roots a healthy growing environment.

Soil profile. Photo courtesy UF/IFAS.

Soil profile. Photo courtesy UF/IFAS.

Soils are crucial to agricultural production, but they also play important environmental roles. On a global scale, soils are a “sink” for carbon and help combat climate change. At the same time, soils help reduce pollution through filtration and store water to recharge our drinking water aquifers. The water absorbed within healthy soils can help protect communities from both drought and flooding.

Pollution and erosion are among the biggest threats to healthy soil, and governmental agencies at all levels devote considerable funds and staff to protecting this life-giving limited natural resource. To learn more about soil and how to test for soil nutrients and pH, talk to your local Extension agent. There are many great online resources devoted to soil science, such as the Natural Resource Conservation Service’s new “Unlock the Secrets in the Soil” campaign, the USDA’s online soil surveys, and the UF IFAS Soil & Water Science Department newsletter, “Myakka.”

Learning from the Floods

Learning from the Floods

Just over a year ago, southwest Alabama and northwest Florida experienced a devastating storm that left hundreds without access to their homes and businesses, flooded out and stranded by a hurricane-force storm that didn’t come with the luxury of a week’s warning. Rainfall records in Pensacola go back to 1879, and the April 29-30 storm broke them all, estimating just over 20 inches over the two days. Not only was the rainfall heavy, but the torrent was high in both velocity and volume—at one point, a mind-boggling 5.68 inches fell in the span of one hour. That’s half the annual rainfall of many cities in California and Texas!

gas geysers

A residential street in Pensacola became a raging river a year ago during the torrential floods, putting dozens of people out of their homes. Photo credit: Carrie Stevenson UF/IFAS Extension.

With every dark storm cloud comes a silver lining, though, and just like the millions pumped into our regional economy from oil spill-related fines, the April 2014 floods have awakened a “greener” ethic among many residents, business owners, and politicians. According to a study just released by an environmental consulting firm, when asked about infrastructure changes and improvements to flooding and stormwater, attendees at community meetings overwhelmingly preferred “low impact” solutions such as expanded green space, cisterns, rain gardens, and stream restoration to “hard” structures such as bigger underground pipes and more pumps. While traditional engineering infrastructure is still crucial to a community that must maintain roads, stormwater ponds, and buildings, I find it encouraging that residents are interested in trying different techniques that have proven successful both here and in other parts of the world.

rain barrel

The new Langley Bell 4-H Center has four large rain barrels around the building, used to collect roof runoff for landscape design. Photo credit: Carrie Stevenson UF/IFAS Extension.

So, how does one prepare for unexpected rain and floods? The first thing is to realize that northwest Florida receives the most annual rainfall (over 60”) of any region of the state, and sometimes it seems to come down all at once.  Preparing landscapes to handle both frequent and heavy rains is an important place to start.  This article will begin a series of articles delving into those “low-impact” stormwater management techniques that can help lessen the impact of the intense storms we experience here in northwest Florida. Many of these practices, such as creating mulch pathways, harvesting rainwater, and installing shoreline vegetative buffers, can be implemented by individual homeowners and help reduce the impact of flooding on a neighborhood and city-wide level

Waterfront Landscaping

Waterfront Landscaping

A waterfront buffer zone may include a raised berm with native vegetation to slow runoff from a yard before entering the water. Photo credit: Carrie Stevenson

A waterfront buffer zone may include a raised berm with native vegetation to slow runoff from a yard before entering the water. Photo credit: Carrie Stevenson

A taste of spring weather has arrived, and people will soon be filling the home improvement stores and getting ready for outdoor projects. If you live on the water or near a storm drain, it’s worth considering buffer zones and best management practices for fertilizing and lawn maintenance.

A waterfront buffer zone is an area the length of one’s property line, typically running about 10 feet (although it can be wider) from the edge of a shoreline (or even a storm drain) into the yard. In this area, the homeowner allows native vegetation to grow along the water and uses low-maintenance plants within the buffer. In this zone, no fertilizers or pesticides are used. Some homeowners will build a small berm to divide the area of maintained lawn (uphill) from the downhill waterfront side. This berm may be composed of a mulched area with shrubbery to catch and filter runoff from the more highly maintained lawn. This combination of actions helps treat potentially polluted stormwater runoff before it reaches the water, and keeps homeowners from using chemicals close to the water. It is often quite difficult to grow turf next to the water, anyway, and this takes the pressure off of someone trying to grow the perfect lawn down to the water’s edge. The buffer zones are often quite attractive and can be an excellent transition between managed turf and the waterfront.

Unmaintained dirt roads along creeks are significant sources of sediment, which can harm the bottom-dwelling insects that form the base of the food web. Photo credit: Carrie Stevenson

Unmaintained dirt roads along creeks are significant sources of sediment, which can harm the bottom-dwelling insects that form the base of the food web. Photo credit: Carrie Stevenson

Erosion prevention is crucial along waterways, as well. An open, non-vegetated lot can contribute a significant amount of sediment to a storm drain, stormwater pond, or natural body of water. Whether grass, trees, or bushes, any kind of vegetation is preferable to soil washing out of a yard and into the water. Sediment is a problem because it causes water clarity to drop, which can prevent seagrasses from getting the sunlight they need. Once settled, underwater sediment can form a stifling layer that chokes out small insects and invertebrates, which live in the soil and form the basis of the aquatic food chain. With no fish food available, fish may die or move out of an area. The most dramatic examples of this can often be found at dirt roads that cross over creeks. If not managed properly, the clay on these roads can nearly bury a small stream.

Other lawn care techniques for protecting the waterfront and preventing stormwater pollution include not mowing along the water, using a deflector shield and staying 3’-10’ away from the water’s edge when fertilizing, and not allowing grass clippings to blow into storm drains. Large amounts of decaying grass in a waterway can use up available oxygen, endangering aquatic organisms. When applying granular fertilizer, be sure to sweep up any spills on concrete so it doesn’t run into a storm drain. When cutting grass, mow at the highest height recommended for your turf to encourage deep rooting and stress tolerance. Healthy turf is better able to withstand drought, pests, and choke out weeds, reducing the frequency of pesticide and water application.

Leaf Litter: Do the Benefits Outweigh the Work?

Leaf Litter: Do the Benefits Outweigh the Work?

Fallen leaves add much to the landscape. They feed the plants and many insect, retain water, and help stabilize the soil

Fallen leaves add much to the landscape. They feed the plants and many insect, retain water, and help stabilize the soil

For the homeowner who feels the need to rake leaves and pine needles, the task can be something of a minor nuisance. The showers of earth-toned leftovers appear suddenly and at inconvenient times, and their removal is never added to a chore list without dispute.

Disarray aside, these organic remnants provide far more benefits than problems. Their suburban untidiness becomes an insulating blanket which nurtures plants, animals, and insects with time released nutrients for use by the efficient and fortunate in the wild and those of us in civilization.

First and foremost, leaf litter is critical to the water holding capacity of the woodlands. The dried leaves, needles and twigs absorb and shade rainwater from the evaporative effects of the sun and wind.

When heavy rains inundate the soil causing flooding and runoff, it is the leaves that act as part of the natural delaying system to minimize the negative impact on streams, creeks and rivers. The delayed or halted runoff provides time for water to be absorbed by the soil and be filtered by the natural screening capacity of this organic material.

The moisture works in conjunction with native bacteria and fungus to convert the leaf litter into nutrients usable by plants and trees. While not as concentrated as commercial fertilizers, many of the same plant nutrients are present in the decaying leaf litter.

The decomposition is aided by a variety of insects and worms which nest in, eat and overwinter under the debris. The animal activity breaks up and stirs the elements along with inoculating microbes in the matter which speeds nutrient availability to plants and trees during ideal years.

Luckily, the region’s leaf drop is spread over months with the plants and trees responding to the solar cycle and weather. Autumn, winter and spring each bring defoliation of specific trees and plants.

During dry years the bug and bacteria activity slows in accumulated leaf litter, but the naturally occurring fire cycle continues the nutrient recycling under the tree canopies. The easy to burn material aides in controlling insects and plants that can aggressively overpopulate an area if unchecked.

Controlled burns also prevent destructive wildfires which are harmful to all north Florida residents. While these uncontrolled fires do deposit nutrients, they have many negative effects which far outweigh this single benefit.

January’s weather is part of a continuing natural succession which the native plants and trees incorporate to continue the wild beauty so common in the region. The current cold and rain will combine with the leaf drop to produce much growth in the next few months.