by Eddie Powell | Jan 22, 2015
Florida homeowners enjoy a wide range of landscape and citrus plants and often times desire a tropical or semitropical appearance to their landscapes. Many landscape plants are often planted past their northern limit such as here in Northwest Florida, although microclimates differ dramatically. Tropical and subtropical plants can be used in the landscape, but they must be protected or replaced if necessary during cold weather. A good variety of tender and hardy plants should be planted in order to prevent total devastation of the landscape by extremely cold weather.
The site selection for tender plants should be number one on your list when preparing for a freeze. Tender ornamental plants need a higher site with good air drainage, and not in a low area where cold air settles. Arranging tender plants along fences or other barriers to protect them from cold winds improves the plants’ cold protection, especially from very hard freezes.
Poorly drained soils result in weak shallow roots which are more susceptible to cold injury. Plants grown with the correctly applied rate of nutrients will tolerate colder temperatures better and recover from cold injury faster than plants grown with little or no added nutrients. Be aware that late fall fertilizing of nutrient deficient plants or fertilization before unseasonably warm periods can result in a late growth which is more susceptible to cold injury.
Ornamental plants that are planted under large tree canopies can have more cold protection and require less cold prevention for the owner.
Watering landscape plants before a freeze can help protect plants. A well watered soil will absorb more solar radiation than dry soil and will reradiate heat during the night by as much as 2°F . However, saturated soil conditions can damage the root systems of most plants over a few days, so make sure the ground is well drained.
Avoid late summer or early fall pruning which can alter the plant hormonal balance resulting a flush of new growth. This new growth is more susceptible to cold injury. Healthy plants are more resistant to cold than plants weakened by disease, insect damage, or nematode damage. Routine inspection for pests and implementation of necessary control measures are essential.
Here are a few methods for plant protection. Plants in pots or containers must be moved indoors where heat can be available to them. Containers that have to be left outdoors should be protected by mulches around the container or root ball of plants in the landscape to reduce heat loss from container sidewalls.
Cold Protection for Veggies!
Coverings can help protect plants more from frost than from extreme cold. Covers that extend to the ground and are not in contact with plant foliage can lessen cold injury to the plant. Foliage in contact with the cover is often cold burned or injured because of heat transfer from the foliage to the colder cover. Some examples of excellent plant covers are cloth sheets, quilts or black plastic. If plastic covering is used, it is extremely important to remove the covering during the day to provide ventilation of trapped heat. A light bulb under a covering also is a simple method of providing heat to ornamental plants in the landscape during the night hours.
Cold Damage on Fruit Tree
Pictures By Eddie Powell
Immediately after the frigid weather has passed, plants need to be checked for water loss. The foliage could be losing water vapor or transpiring on a sunny day after a freeze while water in the soil or container medium is frozen. Apply water to thaw the soil and provide available water for the plant. Soils or media with high soluble salts should not be allowed to dry out because salts would be concentrated into a small volume of water and can burn plant roots. Root burn can cause the roots to dry out and not take up water to the plant.
Pruning should be delayed until freezing temperatures have risen or until new growth appears to ensure that live wood is not removed. Dead, unsightly leaves may be removed as soon as they turn brown after a freeze if a high level of maintenance is desired. But it is best to wait until the threat of freezing weather is gone. Cold injury may appear as a lack of spring bud break on a portion or all of the plant, or as an overall weak appearance. Cold injury is usually found in the upper portion of the plant. Branch tips may be damaged while older wood underneath is free of injury. Cold injured wood can be identified by examining the cambium layer under the bark for black or brown coloration. Prune these branches back to a bud 2-3 inches behind the point of discoloration.
For more information on freeze protection of plants see:
Cold Protection of Landscape Plants
by Sheila Dunning | Dec 23, 2014
A frozen perennial plant. Photo credit: Taylor Vandiver UF/IFAS Extension.
When you look out at your landscape nobody has to tell you that winter temperatures in Northwest Florida Afterwards, the temperatures warm up and you feel compelled to do something about it. You just need to “turn your back and slam the door”. “Conceal, don’t feel; don’t let them know”. Cold injury can affect the entire plant or just certain plant or parts such as fruits, flowers, buds, leaves, trunks, stems, or roots. Many plant parts can adapt to tolerate cold. Root systems in the landscape are seldom ‘frozen’ in Florida. “The cold never bothered” them “anyway”. While dead, unsightly leaves may be removed as soon as they turn brown after a freeze, the remaining dry looking stems serve as food storage and should be allowed to remain. If they are removed before the weather is warm enough for the plant to resume growth, the root system may not be enough to support the plant and it will die. So, “let it go, let it go, let it go”. “The perfect” landscape “is gone”. “The past is in the past”. “It’s funny how some distance makes everything seem so small”.Tropical plants and summer annuals do not adapt or harden to withstand temperatures below freezing, and many suffer injury at temperatures below 50°F (10°C). Subtropical plants can harden or acclimate (become accustomed to a new climate) to withstand freezing temperatures, and properly conditioned temperate plants can withstand temperatures substantially below freezing.
Recently planted, unestablished plants may be more susceptible to cold injury. One type of winter injury is plant desiccation or drying out. This is characterized by marginal or leaf tip burn in mild cases and totally brown leaves in severe cases. Desiccation occurs when dry winds and solar radiation result in the loss of more water from the leaves than can be absorbed and/or transported by a cold root system. Plant water needs should be checked after a freeze. Plants may have lost substantial moisture during a windy freeze. Plants will transpire (lose water vapor) on a sunny day after a freeze. Cold injured wood can be identified by lightly scraping the bark with your fingernail and examining the color of the cambium layer (food conducting tissue) just underneath. Green tissue indicates the plant is still alive at that point; black or brown coloration indicates dead or injured tissue. 
After a particularly harsh cold event, some plants may be very slow to recover, so some patience is required. “It will rise” with “the break of spring”. Branch tips may be damaged while older wood is free of injury. Delay pruning until new growth appears next spring to ensure that live wood is not removed. In the meantime, take Elsa’s advice and “let it go, let it go, let it go”. You may be “too relieved to grieve”. I hope I haven’t infringed on any copyrights by letting you know “It’s okay to put off the yard work in the name of plant physiology”.
Enjoy the holiday season!
For more information please see:
Treating Cold Damaged Plants
by Gary Knox | Nov 25, 2014
View of the Discovery Garden in Gardens of the Big Bend.
Weeping false butterflybush, Rostrinucula dependens, is a new and unusual perennial being evaluated in Gardens of the Big Bend.
Gardens of the Big Bend is a new botanical and teaching garden located on the grounds of the University of Florida/IFAS North Florida Research and Education Center in Quincy. The goals of these gardens are to evaluate new plants, promote garden plants adapted to the region, demonstrate environmentally sound principles of landscaping and provide a beautiful and educational environment for students, visitors, gardeners and Green Industry professionals.Located just 10 miles south of the Georgia-Florida border in Florida’s “Big Bend,” the Gardens are in USDA Cold Hardiness Zone 8b and have sandy-clay soils more typical of continental conditions than those of peninsular Florida.
Gardens of the Big Bend is a series of gardens, each with a theme or plant focus:
- The Discovery Garden contains over 170 species or cultivars of new, improved or underutilized trees, shrubs and perennials. The garden’s purpose is to help gardeners, landscapers and nursery growers “discover” new plants.
- The Magnolia Garden is part of the National Collection of Magnolia in recognition of its’ more than 200 species and cultivars, including some of the rarest magnolias in the world.
- The Crapemyrtle Garden includes six species and over 100 cultivars.
- Conifers can be found throughout the Gardens but are featured in the new “Jurassic” garden. More than just pines and junipers, the Gardens contain over 50 conifer species and cultivars, many of which are rare. In recognition, the American Conifer Society has designated the Gardens as a “Conifer Reference Garden”, the only one in Florida, and the southernmost in the U.S.
- The Dry Garden is the newest addition and contains about 140 different types of agave, aloe, cactus, dyckia, sedum, yucca, bulbs and other dry-adapted plants. It consists of a south-facing berm of boulders, gravel and sand about 160 feet long, 35 feet wide and 6 feet tall.
- Other gardens feature native, shade, Southern heritage, and weeping plants as well as collections of Japanese hydrangea and shrub roses. Additional gardens will be installed as time and funding permit.
Parana pine, Araucaria angustifolia, is a rare type of conifer in the Gardens.
Gardens of the Big Bend formally began in 2008 thanks to the happy marriage of a new volunteer organization coupled with this University of Florida off-campus facility and plant collections I developed as part of research and extension projects. The volunteer organization, Gardening Friends of the Big Bend, Inc., formed in 2007 to support horticulture research and education. This group quickly seized on the idea of transplanting these existing plant collections into a series of gardens. Accordingly, its members hold fundraisers, provide volunteer labor and sponsor extension programs to raise awareness, provide funds and support garden development and maintenance.
Gardens of the Big Bend is located in Quincy at I-10 Exit 181, just 1/8 mile north on Pat Thomas Highway (SR 267). The gardens are free and open to the public during daylight hours year-round; professional staff are only available during normal business hours. To make a gift to the Gardens, please go to this website! Come visit us and watch the Gardens grow!
by Mary Salinas | Nov 18, 2014
Blue Mistflower – Image Credit Mary Derrick, UF / IFAS
Here’s a beautiful native perennial wildflower that is easy to grow and generally available in the independent nursery trade. In the wild, you can encounter them at the edges of woodlands and ponds as they prefer moist areas. Blue mistflower, Conoclinium coelestinum, performs well as a perennial in the home landscape but does spread easily by seed and will spread in the garden. It also spreads through underground rhizomes which allow it to form large clumps. This is an advantage for the informal garden, however, the gardener who prefers a more formal look will have a bit more maintenance in controlling that spread.
The abundant flowers look like bluish-purple puffballs on the top of the stems. The color is unusual and adds a striking touch in the garden. The bloom season is mid-summer to mid-fall. Butterflies are frequent visitors, making this an excellent addition to your butterfly garden.
Blue mistflower has a full rounded form and will grow to 3 feet under optimum conditions. Leaves are opposite and have a triangular shape. Growth and blooming is best in full sun to part sun conditions.
Give it a try!
by Taylor Vandiver | Oct 7, 2014
I think it’s safe to say fall is officially here. Shouts can be heard from local football stadiums, occasionally a crisp fall breeze will send us looking for a light jacket, and coffee shops are pushing all things pumpkin. Now that we can officially appreciate the cooler fall weather, it may be time to stretch our legs and marvel at the spectacular show of color our landscapes are putting on. Here are a few plants that are showing off this time of year.
Firebush (Hamelia patens) – This charming Florida native will delight everyone with beautiful orange-red flowers throughout most of the year. Hummingbirds and butterflies enjoy the nectar in the flowers. Firebush can reach a height and width of 8 to 12 feet. It is a fast growing plant that will grow well in part to full sun environments.
Bright orange-red blooms on a firebush. Photo courtesy UF/IFAS.
Salvia (Salvia spp.) – Salvias are great plants for bringing butterflies and hummingbirds to your garden and as a bonus, they have no serious pests. With hundreds of annual and perennial species coming in an array of colors and sizes, you can easily find one or more to complement your landscape. Salvias perform best in full sun environments and are considered drought tolerant.
Deep purple blooms on a salvia in the landscape. Photo courtesy Taylor Vandiver.
Turk’s Cap (Malvaviscus arboreus) – Turk’s cap can add a cheerful pop of color at a time when little else is blooming. This old-fashioned Florida-Friendly shrub like perennial is related to the hibiscus. It’s known for its bright red flowers that always seem ready to open, but never do. Turk’s cap starts blooming in summer and keeps going until through winter, unless hit by a hard frost. It can grow in full sun and reach up to ten feet tall and ten feet wide, so give it room to grow. This easy-care native perennial requires little maintenance once it’s established.
Turk’s cap showing off its unique blooms. Photo courtesy Taylor Vandiver
Coleus (Solenostemon scutellarioides) – When imagining fall color we often don’t consider coleus. However, the vibrant foliage can add interest to any landscape throughout the fall. Coleus is prized for its colorful foliage, which comes in shades of green, yellow, pink, red, and maroon. Coleus varieties can range from one to several feet in height. They can be used in hanging baskets, containers on patios, or in landscape beds. Coleus prefers partial shade and you can pinch the growing stems of young plants frequently to encourage dense foliage. Keep an eye out for mealybugs on coleus and use insecticidal soap if problems develop
Burnt orange foliage standing out amongst the neutral green of the landscape. Photo courtesy Taylor Vandiver.
Fore more information contact your local extension agent. Also you can visit us at gardeningsolutions.ifas.ufl.edu or edis.ifas.ufl.edu.
by Sheila Dunning | Sep 23, 2014
Photo Credit: Candy Butler, Floridata.com
Looking to add something to brighten your landscape this autumn? Firespike (Odontonema strictum) is a prolific fall bloomer with red tubular flowers that are very popular with hummingbirds and butterflies. Its glossy dark green leaves make an attractive large plant that will grow quite well in moderate shade to full sunlight. In frost-free areas firespike grows as an evergreen semi-woody shrub, spreading by underground sprouts and enlarging to form a thicket. In zones 8 and 9 it usually dies back to the ground in winter and resprouts in spring, producing strikingly beautiful 9-12 inch panicles of crimson flowers beginning at the end of summer and lasting into the winter each year. Firespike is native to open, semi-forested areas of Central America. It has escaped cultivation and become established in disturbed hammocks throughout peninsular Florida, but hasn’t presented an invasive plant problem. Here in the Panhandle, firespike will remain a tender perennial for most locations. It can be grown on a wide range of moderately fertile, sandy soils and is quite drought tolerant. Firespike may be best utilized in the landscape as a mass planting. Plants can be spaced about 2 feet apart to fill in the area quickly. It is one of only a few flowering plants that give good, red color in a partially shaded site. The lovely flowers make firespike an excellent candidate for the cutting garden and is a “must-have” for southern butterfly and hummingbird gardens. Additional plants can be propagated from firespike by division or cuttings. However, white-tailed deer love firespike too, and will eat the leaves, so be prepared to fence it off from “Bambi” if they are a problem in your neighborhood.
Cold Damage on Fruit Tree
