Like finding buried treasure on a desert island, walking up on a mound of sandhill milkweed (Asclepias humistrata) may elicit cries of excitement from someone who understands what they’re seeing. And not unlike searching for pirate booty, there’s a bit of danger involved, too—milkweed is highly toxic.
The eye-catching pink coloration of the leaves, stems, and complex flowers make this variety of milkweed stand out among the dunes. Photo credit: Carrie Stevenson, UF IFAS Extension
Last month in the dunes of Perdido Key, our Master Naturalist class found robust clusters of eye-catching, pink-tinged leaves, blooms, and buds of sandhill milkweed. Also known as pinewoods milkweed, this variety thrives in dry, sandy soils. It is native to the southeast, found typically in the wilds of Alabama, Mississippi, Louisiana, Georgia, Florida, South Carolina, and North Carolina. Its genus name, “Asclepias” refers to the Greek god of healing—indigenous people have used the plant for medicinal purposes (dysentery treatment and wart removal, in particular) for centuries. The species name humistrata means “spreading,” which describes the growth habit of the plant. Milkweed is highly toxic, so we do not recommend trying any medicinal uses at home! The “milk” part of the common name refers to its sap, which is a thick, sticky, white substance containing that toxic chemical.
The seedpods of sandhill milkweed are large and full of seeds with wispy fibers that allow them to float through the air for dispersal. Photo credit: Gabriel Campbell, UF/IFAS
As the only food source for the monarch caterpillar, healthy milkweed plants are crucial for maintaining populations of the famous monarch butterfly. The plant itself is rather complex and beautiful. Its five-petaled blooms grow in tight clusters, on stalks sticking several inches off the ground. The leaves are broad and a deep forest green, edged in the pale maroon/pink of the stems and flowers. The seedpods of milkweed are quite large (3-6” long), resembling pea pods and full of seeds. Each seed has a wispy white fiber attached, which helps it disperse in the wind like a dandelion. The fibers have been used for years as stuffing for pillows and mattresses, and were used for life jackets during World War 2.
Numerous monarch caterpillars feed on a sandhill milkweed plant. Photo credit: Carrie Stevenson, UF IFAS Extension
The first cluster of milkweed we found was host to multiple monarch caterpillars, recognizable by their greenish-yellow, white, and black stripes. By the time you see caterpillars, the milkweed is already working its magic, transferring its toxins to the insects but causing them no harm. Monarchs have evolved the capability to digest and metabolize this poison, which would induce heart attacks in nearly any vertebrate animal. Adult monarchs use several nectar sources, including milkweed flowers, and females lay their eggs on the plant so that their young can begin eating once hatched.
In the animal kingdom, red and orange are signs of danger. The bright orange coloration of an adult monarch butterfly serves as a warning to would-be predators to exhibit caution, as the toxins from their food sources stay within the butterfly’s body. The copycat viceroy, soldier, queen, and Gulf fritillary butterflies benefit from this trait by using mimicry in their own orange coloration to ward off predators.
Syrphid larva and oleander aphids. Photo credit: Lyle Buss, University of Florida.
When we think of pests we tend to focus mainly on insects. Insects make up roughly 80% of animal life, however only about one percent of insects are considered pests. The rest help pollinate crops, kill pests, clean up dead stuff, and make honey. Unfortunately, plants suffer from many more types of pests such as weeds, disease, and us. This episode of “Gardening in the Panhandle LIVE!” was all about managing pests.
Many soft-bodied insect pests can be controlled with insecticidal soap. Many insecticidal soaps are on the market that can help control pests like aphids and whiteflies. However, dish soaps are manufactured for cleaning dishes and not labeled for pest control. More information on insecticidal soaps can be found in the publication “Managing Plant Pests with Soaps”.
Although dish soap isn’t a good option for insect control, there are some things from around the house that can be used to help manage pests. The publication “Do-It-Yourself Insect Pest Traps” offers some excellent options for monitoring and managing pests with traps.
Florida is home to a plethora of insect pests. The Ask IFAS website has many articles on insect pests common in the garden.
Companion planting is the practice of planting two or more plant species close to each other to improve growth and/or pest control of one or more of the species. The article “Companion Planting: What is it?” offers some great recommendations and examples of this technique. Marigolds are an excellent companion plant because they can help deter and suppress nematode populations.
Some people prefer to only use naturally derived products for pest control. The publication “Natural Products for Landscape and Garden Pests in Florida” extensively reviews some of these products. Bacillus thuringiensis (BT) is a bacteria found in soil that can be used for caterpillar pest control.
We love our squash, cucumbers, and watermelons in the South, however there are a number of insects that like to eat them too. More information on cucurbit insect pests and their management can be found in the publication “Insect Management for Cucurbits”.
Armyworms like to feed on just about everything. The Ask IFAS website has a nice collection of publications on all types of armyworms.
Some fungi are fun to eat while others kill our landscape plants. One common fungal disease found in the landscape is Entomosporium leaf spot. This disease is very common on Indian hawthorns. The article “Keep an Eye on Your Indian Hawthorn” describes this disease and it’s control.
Aphids are a very common insect pest. In fact, some plant species have specific aphids. More information on different aphid species and their control can be found in the publication “Aphids on Landscape Plants”.
A plant in the wrong place is considered a weed. Some plants are particularly good at finding the wrong place and can take over our lawns. The publication “Weed Management Guide for Florida Lawns” offers solutions on controlling common lawn weeds.
Cockroaches do a nice job cleaning up litter when they’re outside, but we don’t need want them in our houses whether they’re cleaning up trash or not. The publication “Cockroaches and Their Management” is a great resource for cockroach species identification and management.
As previously mentioned, there are a lot more good insects than bad insects. For more information on predatory insects and biological controls check out the publication “Natural Enemies and Biological Control”.
Nature is fascinating and most people are lifetime learners. To help find out what you’re looking at, give the iNaturalist website and app a try.
Armadillos don’t mean any harm and can be kind of cute. However, they can make a mess of our yard and they build their dens in some undesirable locations. The publication “The Nine-Banded Armadillo” provides information on armadillos and their management.
Fire ants are pests of our lawns and pastures and their sting is brutal. For more information on fire ants please refer to the publication “Managing Imported Fire Ants in Urban Areas”.
Pests can be pesky, but they are manageable if you keep up with the art and science of their control. If you need help with identification and pest management options please don’t hesitate to contact your local Extension Office.
Past episodes of Gardening in the Panhandle LIVE can be found on our YouTube playlist.
Hurricane Season starts June 1 so we are are revisiting a video that discusses tree issues and property lines. There are often questions about who is responsible when storm-damaged trees end up on a neighbor’s property. UF IFAS Escambia County Extension discusses a few common situations using legal interpretations from the UF publication HANDBOOK OF FLORIDA FENCE AND PROPERTY LAW: TREES AND LANDOWNER RESPONSIBILITY.
Written by: De’Anthony Price, Agriculture & Natural Resources Extension Agent, UF/IFAS Extension – Jefferson County
Florida is the perfect place to grow sweet potatoes (Ipomea batatas). Sweet potatoes are considered a long-season crop, and Florida’s long, hot summers allow them to grow and mature well here.
Sweet potatoes are native to America and known for their colorful and tasty tubers. Their flesh can be yellow, orange, or even purple. They are a great source of vitamins A and C. Sweet potatoes are an excellent warm-season crop for Florida. They require a long growing season but will reward you greatly for your patience. The leaves are edible as well. Not only are they nutritious, but the young leaves and shoots also provide a source of tender and mild-tasting leafy greens through the hot Florida summer. Sweet potatoes are a healthier alternative to white potatoes with a high glycemic index. The starch from a white potato is quickly metabolized, leading to a rapid increase in blood sugar. Sweet potato starches are metabolized at a slower rate.
Sweet potatoes are ideal for filling the gap between summer and fall crops as they have a long growing season. Photo by Janis Piotrowski.
Planting and Care
Sweet potatoes can be planted in the spring through the end of June. Sweet potatoes grow in a well-drained loamy to sandy soil and do not require much fertilizing. If the soil contains clay, add some aged compost or other organic amendments to the planting bed to improve drainage. Sweet potatoes grown in unamended clay soils are usually small.
Sweet potatoes are generally planted from March through June in the Florida Panhandle. Sweet potatoes are typically started from transplants called “slips.” Sweet potato slips are six to eight-inch sweet potato vine cuttings with most of the leaves pulled off. You can purchase sweet potato slips from a local garden center or a seed catalog. Make sure you only buy certified, disease-free slips. One can also quickly start your sweet potato slips from a store-bought sweet potato. Sweet potato weevils can be a severe problem and starting with certified-free transplants can help you avoid issues.
Plant sweet potatoes in rows spaced 48 to 54 inches apart, with 12 to 14 inches between each plant. Look for transplants that are about 6 to 9 inches long. Sweet potatoes will do best when they receive a consistent water supply; inconsistent watering can cause them to split while growing. Sweet potatoes can be kept throughout the season using vine cuttings to create new plants.
Wireworms and root-knot nematodes are the biggest problems for home gardeners. However, many insect and disease problems can be avoided by choosing disease-resistant varieties and using sound cultural gardening practices. Crop rotation with a vegetable in another family can help prevent nematode and soil disease. Rotating where you plant can help prevent problems with a major pest, the sweet-potato weevil (Cylas formicarius).
Damage to sweet potato tuber caused by larval feeding of the sweetpotato weevil, Cylas formicarius. Photo Credit: James Castner, University of Florida.
For the tastiest sweet potatoes, always dig up the previous crop and start a new planting. While sweet potatoes can be grown year-round in tropical regions, plants left to grow for too long can encourage pest populations. The sweet potatoes eventually become too large and tough for most people’s tastes.
Florida-friendly varieties
‘Centennial’ and ‘Beauregard’ are two varieties that grow well in Florida gardens. Beauregard is found quite often in garden centers. It shows some disease resistance and produces a high yield. It has light rose skin and a deep orange flesh that matures in 105 days. Centennial sweet potatoes tolerate clay soil, are disease resistant, and mature in 90 days.
Harvest and Storage
Sweet potatoes should be ready to harvest 90–120 days after planting. The tops will die back as it gets close to harvest time. Sweet potatoes should be harvested before the first frost. Cool soil reduces their quality and storage life. Sweet potato skin is fragile, so freshly dug roots need to be handled gently.
The ideal conditions for curing sweet potatoes are roughly 85°F with 90 percent humidity. To help increase their sweetness, place harvested sweet potatoes in a dark, warm room for at least two weeks before eating. Once your sweet potatoes are done curing, store them in a cool, dry pantry—not the refrigerator! Storing your sweet potatoes at temperatures below 50°F can cause them to have an off flavor or rot. Patience will pay off with delicious and healthy sweet potatoes that can be added to the dinner plate as a vegetable side or in a sweet pie served for dessert. While “yam” is sometimes used to describe the sweet potato, a true yam comes from a different plant.
Written by: Muhammad Adnan Shahid and Shahid Iqbal.
UF/IFAS Horticultural Sciences Department, North Florida Research and Education Center, Quincy FL
Biostimulants are a type of substance or microorganism applied to plants to improve their nutrient efficiency and resistance against abiotic stress (salinity, cold, heat, UV, flooding, drought, heavy metal toxicity, nutrient deficiency), diseases, and quality traits. Due to the increase in world population, the growing pressure on crop productivity is a demanding challenge; therefore, it is necessary to reduce the use of agrochemicals with negative impacts on human health and the environment. Thus, new strategies from the bio-based industry must be found and adopted. Citrus is a highly desirable and profitable fruit crop with undesirable characteristics like excessive flowering and physiological fruit disorder that negatively affect the market value.
Biostimulant Types and Practical Application
Many crop growers have expressed an interest in biostimulants in recent years. As these products gain popularity, we have found that there’s still a lot of controversy about their efficacy. Before determining whether Extension endorses them, let’s review the various types and their practical usage.
Several types of biostimulants include humic and fulvic acid, seaweed extracts, protein hydrolysates, chitosan, beneficial bacteria, fungi and microbial inoculants, and other types of amino acids and polyamines. These products are commercially available with different formulations and ingredients and have immense potential in horticultural crop production, especially in citrus.
Plant biostimulants can be applied through foliar application, fertigation, or directly through the soil, enhancing crop growth and quality. Biostimulants could reduce plant environmental threats and minimize the negative consequences of unsystematic chemical application.
Benefits of Using Biostimulants in Citrus Crop Production
Biostimulant products improve plants’ overall health and help maximize fruit production and quality by providing complete nutrition. The benefits of using biostimulants are highlighted below.
Improve plant metabolism to induce high-yield and quality.
Enhance soil fertility by fostering complementary soil microorganisms.
Increase tolerance against abiotic stresses.
Facilitate nutrients and their movement inside the plant vessels
Boost fruit quality attributes like color, sugar content, etc.
Application of biostimulants and its effect on plant growth and quality traits.
Concluding remarks and recommendations
Biostimulants are in the frontline as a novel strategy to achieve the goal of sustainable citrus crop production, yield, and superior quality. Proper management practices are important for high-yield and quality fruit in citrus production. The use of biostimulant products can provide producers with sustainable production. Before using these products, contact a regional extension specialist or citrus expert for their proper application and trail setup. The Fruit Physiology Lab at North Florida Research and Education Centre (NFREC), Quincy, Florida has started a research project on determining the efficacy and efficiency of different microbial and non-microbial biostimulants in cold hardy citrus production, to improve yield, and fruit quality. For any further information on the use of biostimulants please contact Dr. Muhammad Shahid, Fruit Physiologist/Assistant Professor of Horticulture at mshahid@ufl.edu.
