Spending time outdoors during the Florida summer is not for the faint of heart. It’s hot! And it’s humid! Just moving around outside for a moment in the early morning causes you to break out in a sweat. Most evenings, even after the sun is low in the western sky, but there’s still enough light to enjoy the outdoors, the sweat doesn’t stop. A Floridian’s only hope is that nearby, there is a large shade tree to take cover under. In north Florida, there’s nothing more inviting than a huge live oak draped in Spanish moss for a drink of ice water and a slight breeze. If you don’t have such a spot, start thinking about planting a shade tree this winter!
A large live oak is great for shade! Credit: Dawn Reed.
In north Florida, we have many options to choose from, as we live in an area of the United States with some of the highest native tree abundance. Making sure you get the right tree for the right place is important so make a plan. Where could this tree go? Is there plenty of space between the tree and any structures? You’ll want to give a nice shade tree plenty of room – 20’ to 60’ away from structures and/or from other large trees – to grow into a great specimen. Be sure not to place a large tree under powerlines or on top of underground infrastructure. You can “Call 811 before you dig” to help figure that out. If space is limited, you may want to consider trees that have been shown to be more resilient to tropical weather. Also try and place the tree in a way that provides added shade to your home. Deciduous trees planted along your home’s southeast to southwest exposure provide shade during the summer and let in the sun during the cooler winter. However, be careful that the tree doesn’t grow to block the sun from your vegetable garden!
A density gradient map of native trees in the US. Notice where the highest number occur. Credit: Biota of North America Program.
Here are some ideas for shade trees, those trees that are tall (mature height greater than 50’) and cast a lot of shade (mature spread greater than 30’). All of these are native trees, which have the added benefit of providing food and shelter to native wildlife.
Even with this young sycamore, you’ll be made in the shade. Credit: UF/IFAS.
While it may take a while for you to relax under the shade of your tree, they can surprise you in their growth and, as they say, there’s no time like the present. If you have questions on selecting or planting shade trees, contact your local UF/IFAS Extension office.
North Florida vegetable gardeners have made it to summer and now the plants and gardeners are starting to give in to the heat and humidity. The squash has likely succumbed to squash vine borers, many of the tomato varieties are having trouble setting fruit, stink bugs are all over, and gardeners easily wilt by noon. This is a good time to use our oppressive heat to your advantage in the vegetable garden by solarizing the soil.
We have reached the peak of heat. Use it to your advantage in the garden. Source: National Weather Service.
Soil solarization is a method of pest control that creates a greenhouse to heat up the soil in an effort to drive away pests. Pests that can be reduced with soil solarization include weeds, various soil-borne fungal pathogens, and nematodes. Weed seeds can actually be killed by the increased temperatures, sometimes as high as 140 degrees Fahrenheit, while fungi and nematodes are merely driven deeper into the soil layer as they try to escape the heat. Although they are not killed, this can help vegetable gardeners as it may take these organisms 3-4 months to repopulate in high enough numbers to cause damage. Soil solarization can be considered another tool in your integrated pest management (IPM) toolbox, along with other cultural, physical, and chemical means of pest control.
A raised bed being solarized over the summer. Source: Evelyn Gonzalez, UF/IFAS Master Gardener Volunteer.
To properly execute soil solarization, the site should be in full sun and the existing vegetation removed, either by hand or with a tiller or other implement. Tilling can help loosen the soil surface and allow heat to penetrate deeper in the soil horizon. Before being covered with plastic, the area should receive rainfall or be irrigated, as the water will help conduct heat to greater depths. The next step is to cover the area with plastic. Note that this can also be done over raised beds! Clear plastic is best for maximum solar radiation penetration. Black plastic will heat up mostly on the surface and opaque plastic sheeting may not let enough light in to get temperatures high enough. The plastic should be slightly larger than the area covered, as the edges will need to be buried to create an air-tight seal. It’s recommended to leave the plastic in place for at least six to eight weeks, just in time to begin fall gardening preparations.
It’s important to monitor the site while it’s “cooking” to look for any holes that might appear. Small holes can be repaired with duct tape, while large holes or rips in the plastic may require starting over. Overlapping strips of plastic is not recommended since too much heat will be lost.
You may be wondering what happens to all of the good soil microbes. Well, unfortunately, they are also either killed or suppressed. Fortunately, researchers have found that they are able to repopulate quicker than the pest organisms, especially in soils with a good amount of organic matter.
Much more information on soil solarization can be found in these two documents:
Are you interested in growing lettuce and other leafy greens? Are you looking for tips on extending the growing season for your leafy green crop? If so, then check out this very informative instructional video by Washington County Horticulture Agent Matthew Orwat.
Dwarf lantana – Image UF IFAS Extension, Matthew Orwat
With the heat of summer already here, we all know that our pansies, petunias and snapdragons are on their way out. This leaves us wondering what we could plant that will give us color throughout summer and fall to the first frost.
Many are weary of Lantana camara, the common garden lantana, because of its potential as an invasive species and large rampant size. Good news, there are several dwarf cultivars that have no invasive potential because they are sterile. Additionally, many other dwarf cultivars grow slow and produce few seed, so they have low invasive potential.
Dwarf lantana. Image credit UF/IFAS, Matthew Orwat
Northwest Florida is not in the natural range of the endangered South Florida native Lantana depressa, so the outcrossing danger does not exist in our area.
Dwarf lantanas are available in either mounding or trailing types. Mounding types rarely get over 1 foot tall and have an equal spread while trailing lantanas stay lower to the ground but can spread several feet. They are available in several colors including yellow, purple, white, multicolor and red. They provide reliable color in flushes from late spring until first frost
When mature, dwarf lantana are drought tolerant but need supplemental watering to get established. They also thrive in poor soils and need little fertilization.
Dwarf lantana usually acts as a perennial, but die to the roots during extremely cold winters.
Lantanas that are known to be relatively non-invasive include Patriot, Hallelujah, Sunburst, and Cowboy. Florida Exotic Pest Plant Council recognizes the cultivars ‘Gold Mound’, ‘New Gold’, ‘Alba’ and ‘Patriot’ as cultivars that are not known to produce viable seeds. Other newer dwarf varieties need to be evaluated on a case by case basis, but varieties the author has observed as no to low seed set in the landscape. Also if home gardeners are worried about seed production, spent blooms can be pinched off so no seed can form. This pinching off practice also speeds up re-bloom and is thus highly encouraged.
Expect typical heat and humidity east of the Apalachicola River with hotter temperatures west. http://www.accuweather.com/en/weather-video/video-summer-2014-forecast-highlights-drought-severe-weather-increase/3520160310001
As we begin to approach our North Florida hot summer months, Gary Wade with the University of Georgia College of Agriculture and Environmental Sciences Cooperative Extension reminds us that, “temperatures in the high 90s and several weeks without rain can lead to serious, sometimes fatal, conditions for landscape (and garden) plants“. Most likely, we will also experience extreme temperatures in June and July. Under these conditions, heat stress is a great concern for both plants and people in the landscape or garden. Remaining hydrated is key to preventing heat stress.
For plants, mulching is an effective means to conserve moisture in the soil. It also cools the plant root zone, and helps to control weeds. Removing weeds that are growing around desirable plants will also help reduce soil moisture losses.
Consider watering your garden or landscape early in the morning. This method takes advantage of cooler morning temperatures, which can extend soil moisture conditions thus making soil moisture available during the hottest times of the day. Early morning watering will also discourage disease problems on plants susceptible to fungal growth such as lawns, roses, and cucurbits.
The best time to work in the garden or landscape is during the morning hours. To beat the heat, stay hydrated by drinking plenty of water. Heat stress disorders develop when the body cannot shed excess heat. Heat stress, heat exhaustion, and heat stroke are illnesses that can overcome you when your body is unable to cool itself. For more information and resources on how to “Beat the Heat”, visit the UF IFAS Solutions page.
Ref: Wade, G. 2013. Heat, Drought Take Toll on Landscape Plants. University of Georgia College of Agricultural and Environmental Sciences Cooperative Extension.
