by Mary Salinas | Feb 2, 2015
So often, homeowners wait until weeds have overtaken their lawns in mid-summer before looking for a course of action to control them. Unfortunately, when weeds get to maturity and start producing flowers and going to seed, they are usually quite difficult to control.
[important]The best strategy is to prevent the weeds from getting established in the first place![/important]
Florida pusley, an annual weed that can be controlled with preemergence herbicides. Photo credit: Mary Derrick UF/IFAS Extension.
When properly applied, a preemergence herbicide forms a chemical barrier on the surface of the soil that kills newly germinated seeds when they grow and contact that barrier. Be sure to follow label directions carefully as it is crucial to apply the correct amount and water it in correctly. The soil surface should not be disturbed after application to ensure that the chemical barrier remains intact.
Keep in mind that preemergence herbicides only prevent annual weeds! They do not control weeds that have already emerged.
In North Florida, the time to apply a preemergence herbicide to your turfgrass is coming soon. As a general rule, March 1 is an ideal time. Another indicator that the time is right is when the daytime temperatures reach 65°F-70°F for 4 to 5 consecutive days as that sustained warmth will prompt weed seeds to germinate. Oftentimes, this is also when azaleas or dogwoods start blooming and that can clue you into when to apply the herbicide. For best results, follow up with a second application in 6 to 9 weeks to control those seeds germinating later in the season.
Always follow the label instructions precisely when applying any herbicide! Ensure that you apply the product at the correct rate, that it is suitable for your specific turfgrass and situation, and that it is watered in correctly. For any pesticide, the label is the law!
If your lawn has problems with winter weeds, make a note on your calendar to apply a preemergence herbicide about October 1 in North Florida or when nighttime temperatures drop to 55°F-60°F for several consecutive days.
For more information on weed control in lawns:
Weed Management Guide for Florida Lawns
For general information on lawn care in Florida:
UF/IFAS Gardening Solutions: Lawns
by Larry Williams | Jan 27, 2015
Do you have camellia plants with flower buds that fail to open? Here are possible causes for this problem.
For more information on camellias, contact the UF/IFAS Extension Office in your County or visit http://edis.ifas.ufl.edu/ep002 to access the publication, “Camellias at a Glance.”
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 Taylor Vandiver | Jan 22, 2015
You’re digging up a ridiculously stubborn patch of Florida betony when an earthworm crawls across your path. As you break apart the soil in your hands a world of active organisms is being sifted through your fingers. Fertile soil is teeming with beneficial microbes. It is estimated that there can be billions of microbes in a single gram of soil.
Bacteria, fungi, and protozoa are major players in soil microbial processes. They perform a variety of functions beneficial to soil and the plants growing in that soil. Other soil organisms of importance are nematodes, arthropods, and earthworms.
Soil Food Web. Photo courtesy USDA-NRCS.
Rather than being an inert material, soil houses a dynamic living ecosystem. Most soil organisms are too small to be seen, however they are still performing a great service to gardeners in many ways. These organisms are vitally important to improving the health of our soils. They also play a key role in making nutrients available to plants.
Soil organisms are naturally active during certain times of the year. Most are active during late spring and early summer when the soil is warm and moist. If the soil dries out during the summer months, soil organism activity will decline. During fall months, if there is rain or snow that moistens the soil while it is still warm, soil organisms may resume partial activity. As the soil cools in the fall, many organisms go dormant. It is important for gardeners to note that soil organisms help breakdown certain fertilizers and during the cool, dry months these fertilizers, if applied, will be less available for plants to take up.
Soil profile. Photo courtesy UF/IFAS.
Soil organisms are generally placed within three categories: organisms that are beneficial to plants, organisms that play a neutral role in plant growth, and organisms that are harmful to plants. Creating a favorable environment for beneficial soil organisms can improve plant growth and reduce garden maintenance. Encouraging their efforts is key to building a healthy fertile soil. Here are some ways you can encourage beneficial organisms in your soil:
- Add organic matter to the soil. Soil organisms require a food source from soil amendments (compost, crop residues) and/or mulch.
- Water effectively. Soil organisms are happiest in an environment that is damp, but not soggy. (Avoid over-irrigation because waterlogged soils will be harmful to beneficial soil organisms)
- Avoid unnecessary tilling, as it can destroy the mycorrhizae and soil structure. Instead of tilling, mulch for weed control.
- Avoid pesticide applications that aren’t necessary. Some fungicides, insecticides and herbicides are harmful to various types of soil organisms.
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 | Dec 23, 2014
Poinsettias are one of the most popular plants during the Holiday Season. Poinsettias grow as shrubs in their native southern Mexico but have been bred to become compact, bushy plants perfect as container ornamentals. The showy “flowers” of poinsettias are actually modified leaves called bracts. Usually red in color, modern poinsettia breeding created showy bracts ranging in color from red to pink to white to orange, with lots of variegations and different leaf coloration patterns and sizes. The true flowers on poinsettias are the small green and yellow parts located in the center of each group of bracts.
Photo credit: Tyler Jones UF/IFAS.
Here are some do’s and don’ts to ensure that your poinsettias stay beautiful through the holidays and beyond:
- Do choose plants with true flowers that are greenish. Plants with unopened or newly opened flowers will last longer than those already sporting true flowers dusted with yellow pollen.
- Do choose plants that are bushy and leafy. Plants that have lost their lower leaves usually indicate the plant was mishandled and may decline quickly.
- Do place poinsettias in an area with bright light but not direct sunlight.
- Do keep poinsettias away from children and pets. Poinsettias are not poisonous but still might cause skin irritation and upset stomachs. People allergic to latex should be aware poinsettia sap contains latex-like materials.
- Don’t overwater poinsettias. Only water poinsettias when the top of the soil is dry, and let excess water drain away. Remove the poinsettia from the decorative foil wrapping to allow water to drain out.
- Don’t expose poinsettias to temperature extremes or drafty areas. Poinsettias like the same temperatures as people, so keep them away from cold (temperatures below 50) or heat (temperatures above 80).
After the holidays are over, you can plant poinsettias outdoors. For more information see:
Enjoy Your Poinsettias After the Holidays
In the meantime, enjoy your beautiful poinsettias and Happy Holidays!
