Migratory animals are no stranger to our neck of the woods. Every year, Florida is host to countless creatures as they make their way from one place to another in search of food, nesting sites, or just a change of scene. From hummingbirds to manatees, it can be interesting to watch the annual cycle of nomadic animals.
A gulf frittilary butterfly.
One of the smaller wayfarers we see year-round, but especially when they migrate south in the fall, is the gulf frittilary butterfly, Agraulis vanillae Linnaeus. They spend the warmer months of the year in the southeastern United States, following frost-free weather as temperatures drop. During the winter, they enjoy the sunshine of peninsular Florida.
The gulf frittilary is a medium-sized butterfly, with a wingspan of 2½–3½ inches. Females are larger than males. It is bright orange in color, with black markings on the top of its wings and silvery-white spots on the bottoms. In its larval form, it is also bright orange in color, with dangerous-looking spines along the length of the caterpillar. Despite their appearance, these do not sting.
The gulf frittilary caterpillar looks dangerous, but won’t sting. Please do not eat it, however.
If given a choice its larvae will feed primarily on passionflower (Passiflora incarnataand related species), but have also been seen snacking on buttonsage. Toxins from passionflower concentrate in the larvae and butterflies, making them poisonous to predators – much like the monarch butterfly and its host plant, milkweed. The insect’s bright coloration serves as a warning that it is not to be eaten.
Keep an eye out for these beautiful butterflies and consider planting a passion vine in your landscape to help them out. The caterpillars may eat the leaves, but in giving them a feast you’ll help them grow into adult butterflies. Once they do mature, they are fantastic at pollinating many of our native wildflowers, further beautifying the world around them.
For more information see the University of Florida’s article here.
Not all fall color is a good thing. This statement is especially true when it comes to twig pruners and twig girdlers. These two species of longhorned beetles can certainly disappoint your grand expectations of a beautiful array of fall color. Both species cause the tips of twigs to fall to the ground in late summer, sometimes leaving your trees in an undesirable form.
Twig Pruners
The twig pruner (Elaphidionoides villosus or Anelaphus villosus) is a small longhorned beetle that attacks numerous species of hardwoods. It is usually classified as a secondary pest of declining trees and shrubs. Female twig pruners lay their eggs in late spring at the leaf axils. When the eggs hatch, the grubs bore into twigs and continue to bore as they mature. The larvae then chew concentric rings just underneath the bark. The infested twigs and branches eventually drop to the ground with the larvae inside. The larvae pupate inside the fallen twig throughout the winter.
An adult twig pruner. Photo Credit: University of Georgia
Twig Girdlers
The twig girdler (Oncideres cingulata) is a small longhorned beetle that invades many species of hardwoods. Female twig girdlers lay their eggs in late summer in small twigs (about 3/8 inch diameter) that are covered with a thin layer of bark. The female chews a concentric ring around the outside of the twig, causing the end of the twig to die. The female chews a small notch in the dead twig and lays her eggs. After the eggs hatch, the larvae feed on the dead twigs and develop into adults before chewing their way out. The adults fly away to new host trees.
An adult twig girdler. Photo Credit: Lacy L. Hyche, Auburn University
Management and Control
It’s important to plant the right plant in the right place. Healthy trees and shrubs are the best defense against insect pests. Twig pruners and twig girdlers live in dying or dead twigs and branches. If you have trees that have suffered damage from these pests you will notice an abundance of fallen twig ends around the base of your trees. Rake and remove fallen twigs from around the trees and destroy or dispose them. This will help reduce pruner and girdler numbers in subsequent years.
It has been dry as a bone lately, and your landscape is beginning to reflect that fact. Before you call it the dreaded “D” word you should understand that these dry periods are part of our yearly weather cycle. This year, we are drier than usual which means we are indeed in a drought. This can be alarming as you’ve doubtless spent tons of time and money on your landscape and want it to thrive. Irrigating as much as possible may seem attractive but is not necessarily the best strategy. Let’s first look into a few questions. What happens to your plants when Mother Nature turns off the waterworks? What can be done to prevent the mass die-off of our landscape plants?
Drought Response
Before we delve too deeply into the subject, it’s worth taking a few lines to discuss what happens to plants in periods of drought. Many will close the tiny pinpricks in their leaves known as stomata to prevent water loss. This is known as a drought avoidance strategy, and while seemingly foolproof also prevents moisture absorption while shutting down photosynthesis. If this condition persists, the plant will begin to lose the macronutrient carbon and sugars. When a lack of water becomes long term, the plant will perish as it lacks resources.
UF/IFAS photo: J. Criss
Other plants utilize a drought tolerance strategy. Unlike the avoidance strategy, these plants leave their stomata wide open despite the lack of moisture in the soil. The advantage here is that photosynthesis never stops. They’re banking on a return of water before they perish from dehydration. Most of your landscape plants utilize the first of these strategies. Your gardening habits and strategies are crucial to keep your plants thriving even in our extreme heat.
Gardening Practices
The practices you implement in your gardens are what we refer to in this business as “cultural practices.” You may have heard of these at lectures on Integrated pest management, but they are just as applicable in landscape management.
Irrigation is easily the most crucial of these practices as improper watering is the number one killer of plants. Deeper watering delivered less frequently encourages deeper rooting and higher drought tolerance. Irrigation should occur early in the morning just before sunrise to prevent evaporation and mitigate fungal issues as plant water use begins at sun rise. Frequency and volume are the next critical factors in watering. Turf grasses need 1/2 to 3/4 inch of water, but only when they present the three signs of wilt including folded blades, a bluish-grey hue, and lingering footprints. Bedding and landscape plants are a little trickier as they don’t have standardized signs of wilt. You’ll need to pay close attention for loss of vigor in the leaves which are likely to be subtle. When these signs present, apply enough water to reach their root zone. A great way to extend the time between irrigation events is to amend soils with organic matter and to utilize mulch. These retain moisture keeping your plants less thirsty.
UF/IFAS Photo T. Jones.
Fertilization can be another far more detrimental to plant growth than you think. While it’s true that your plants need nutrition for vigorous growth, only those deficient in the soil are limiting factors. This is simply not possible to create a fertilization strategy without soil testing. Your extension office can facilitate testing, which should occur at a minimum every three years. Balance these deficiencies with your plant’s needs to create a healthy landscape.
Pruning is the final practice to look at for healthy landscapes. Turfgrasses need to be cut at a height conducive to their growth. This varies for each grass type, so make sure you know yours. Landscape plants may also need species specific pruning practices such as deadheading to maintain healthy growth.
To Sum Up
The key takeaway from this article is that stress free plants are more capable of tolerating less than ideal growth environments. Familiarize yourself with the needs of your plants and provide them with what they need to thrive. Very often this means less intensive maintenance practices. For more information, see this Ask IFAS document, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.
If you ever drive in the country during the cooler months, you may notice wheat and oats planted out in the fields. They seem to be “covering” the farmland. Well, that is exactly what they are; they are a cover crop! But, did you know, that cover crops can also be implemented in your garden? You may be asking yourself, “What is a cover crop?” “How can I use that in my garden?” and “How does it benefit me?.” Today we are going to answer these questions.
What is a cover crop? A cover crop is a commodity that is planted when fall or summer gardening has ended to “cover” the area that was previously planted. It is planted in between planting seasons, so you would plant a cover crop in the winter between fall and spring crops. Cover crops are a mechanism to help improve the soil quality of your gardening area over time when it is not being used. The technique of implementing cover crops has been around for over 2,500 years. It is suggested that the Greeks and Romans used cover crop methods. So, if the wheel isn’t broke, don’t fix it!
If you decide to use cover crops in your off season, there are things to consider: your growing season, what will improve the nitrogen fixation for your next season, the contribution the cover crop will give to your organic matter building in the soil, and how it will improve your soil health to increase future yields.
Cover crops can help prevent soil from eroding during the off season. The roots of your cover crop will allow the soil to remain in place and add back organic matter over time. These crops are one of the best options to help improve your soil health of your garden, food plot, raised bed, etc. Like anything else, there are benefits and challenges. Benefits include weed control, soil erosion prevention, improving soil health/recycling of soil nutrients, and potential pollinator habitats. Challenges that cover crops can create are that they can become excessively woody and tall so they become hard to manage and if not timed correctly, your next season’s planting schedule can also be obscured. An example of a taller woody maturing crop would be sunn hemp. Shorter nonwoody options include clovers, vetch, and several types of grasses.
There are many different types of cover crops. Some examples include: winter wheat, red clover, annual rye grass, vetch, English peas, and sunn hemp. These all have characteristics in common: they are weed suppressors, they prevent erosion, a few are strong sources of nitrogen, they build soil matter, and a few even attract pollinators.
Sunn Hemp field at Bettstown Farm in Bainbridge, GA, UF/IFAS Extension A. Payne
When planting your cover crop, be sure that there are no remaining plants from your previous plantings still in your growing area. Clear the area of weeds and any flowers, fruit, or vegetables. The soil will need to be level and as you plant your seed for the cover, broadcast the seed in a back-and-forth motion to ensure even planting. Cover the seeds with a thin layer of topsoil.
The next question you may have, “When do I remove my cover crop to plant my next season?” Cover crops should be terminated when they reach their flowering stage or when they appear to begin producing seed heads. When a cover crop flowers, then it has a reached the point that it has contributed the most it can of the biomass and nutrients to your soil. If they are not terminated before the seed formation stage, then they could become a weed or what is deemed to be a plant out of place in your next crop season. We terminate by mowing or crimping down the crops to where it is flush with soil. The cover crop remains can be left on the soil surface to decompose as mulch. Leaving the cover crop on the top of the soil is considered a no till method. A rule of thumb is to time your cover crop seeding so that you can terminate the crop 3 months prior to planting your next crop.
Cover Crop Termination Example, Photo Credit: D. Leonard, UF/IFAS Calhoun Extension
It has been a hard summer climate wise and as we go into fall it is nice to start getting some relief from the heat. As the heat tones down, we are still facing a drought, which is not as severe as areas to our west but is still significant across much of the Panhandle. In our tree cover, the stress from the harsh summer this year is starting to show. You can see it in trees around the area, and it particularly seems to affect certain trees and conditions more than others. Where you are starting to see it most is in our ever-present pines, which make up the majority of our forest and tree cover in our region. If you keep a look out you may notice some pines in the areas with yellowing or brown needles or that are losing their needles. Those are clear signs of a possible bark beetle attack, which is a common issue when pines are stressed or damaged. Trees planted in the last year that are not yet fully established often show stress in a hot dry summer like this year. Even older and well-established trees in areas are showing some signs of stress from the hot dry conditions we have had this summer. Some trees are less adapted to dryer areas and when planted off site can experience more stress in dry conditions. If you look around across the Panhandle right now you can see clear signs of stress in some trees. It becomes more evident in late summer and early fall as the accumulated stressors of summer push trees into physiological conditions that cause stress responses. The big question is what to do if you notice a landscape tree that is exhibiting signs of stress, particularly drought stress.
Pine damaged by construction equipment. Barking injuries like this can encourage bark beetle attacks. Photo Credit: Ian Stone
For pines the issue is likely to be bark beetles, of which there are several types. All pine bark beetles are native to our area and the degree of damage they do varies by species and conditions. The issue with stressed trees is that most bark beetles attack those trees. When a hot dry summer occurs bark beetle activity increases as the stressed trees become less able to fend off attacks by these beetles. Unfortunately, when bark beetles attack a pine in an area the best answer is prompt removal and disposal of the infected tree material. To protect high value trees in an area where bark beetles are active there are some injection pesticides that can prevent infestation, but once a tree has been infested and begun to show symptoms little can be done to bring it back. When bark beetles attack a stressed pine, most are effectively finishing off a tree that may have died regardless. The key is to prevent them from spreading to other pines in the area or attracting them to a stressed tree in an area. With trees already stressed in our area the big prevention option is not to damage or stress any pines already on the landscape. Most pine bark beetles are attracted to trees by chemicals in pitch and resin given off by wounds or damage. Often the stress from new landscaping projects or construction around pines can cause several to succumb to bark beetles. Your best prevention is to keep equipment well away from the tree and avoid damaging or injuring the tree, especially scraping areas of bark off. Larger and older trees can be vulnerable, as well as overcrowded trees that are too dense or overtopped by others. As the cooler weather approaches bark beetle activity should decrease along with the risk of losing a pine to these pests.
Recently constructed sidewalk. Construction activities extended well into the root zone of the tree, which can cause stress and damage. Photo Credit; Ian Stone
For other trees there are additional precautions that can be taken to lessen the potential that a tree will succumb to drought and other stress. Newly planted trees or those established in the last several years are particularly at risk and should be watered regularly during this dry period. Until rains return, a good method of slowly applying water deeply to the root zone is best. Properly applied mulch can help keep the soil cooler and moist around a newly planted tree. Drip irrigation, soaker hoses, and similar methods are best, and a method that specifically applies water slowly to the tree’s root zone gives the best results. Watering your lawn does not supply sufficient water to landscape trees, especially in drought conditions. Lawn irrigation is designed to apply irrigation needed to the top portion of the soil that is available to the grass. Trees have completely different requirements and need different watering methods and amounts. If you don’t have dedicated irrigation available and you have a tree that needs water, you can use irrigation donuts or bags. These are often a good solution for a tree that needs watering temporarily. Once a tree is well established it usually can withstand even severe drought, but during the establishment phase paying attention to water needs is critical in a summer drought like we have had.
Large established trees are also not immune from the heat and dry conditions that have plagued the Panhandle this summer. Usually when conditions change these trees recover but may abort some branches or exhibit some leaf drop while stressed. Leaf drop is a phenomenon that can occur when deciduous trees are stressed. It is a method of conserving water needs by reducing the leaf demand. Usually, the tree will recover and leaf out again fine next year. A tree may abort some branches or have some branch tips die back to make it through a rough period. Trees that are overcrowded, overtopped, or have other issues are the most at risk from environmental stress. This is why good tree selection along with proper tree care and maintenance is essential. When a hot dry summer like we have had comes along well cared for and maintained trees do best. Trees that prefer more moisture like bald cypress, red maple, sycamore, and some oaks can be planted in dryer sites, but when a severe drought comes along they often don’t have the ability to handle the moisture stress that trees adapted to dryer sites can. This is why site selection is so important, it is when we have extreme conditions that off site plantings typically suffer the worst and those can be larger more established trees.
With the cool weather hopefully we will get a reprieve and some rain soon. Given that fall is one of our dryer periods it may be likely that drought conditions could persist until early winter. Good care and tree maintenance is essential to getting your trees through stressful periods like this summer. For younger trees watering and care is essential while they get established. For older established trees avoid doing any construction or other disturbing activities around them until conditions improve. If you have trees that are exhibiting signs of decline or pest attacks call your local extension office or Florida Forest Service County Forester office. With any luck, colder weather with winter rains will be here soon and trees in our area will recover over the dormant period.
