The Physical Properties of Soil

The Physical Properties of Soil

Understanding soil composition is crucial for successful gardening. Soil is the slow interaction of parent material with regional climates, topography, and soil biota over millennia. The breakdown of parent materials results in layers of material called horizons. A subset of soil science is dedicated naming soils with similar horizon development. In North Florida, three of these soil types predominate. Near the northern border, we find ultisols, these sandy soils have a higher clay content and are suitable for row crops with proper management. Through the center of the Panhandle counties, you’ll find entisols. These are sandy and undeveloped, thus requiring close attention to irrigation and fertilization. Finally, by the coast are spodisols rife with mineral pockets and known for being waterlogged. All are usable for plant growth, and with little knowledge of cultural practices can make your landscape thrive.

Soil horizons of ultisol

Soil horizons of ultisols
Photo: USDA/NRCS

The Panhandle Parent Material

In Florida’s panhandle, the parent material stems from the Citronelle formation transitioning into the Miccosukee formation around Gadsden County. The Citronelle formation consists of unconsolidated quartz (sand), gravel, clay, and mineral deposits from rock formations in the Appalachian Mountains. Clay associated with this formation is the basis for the ultisol concentrations in the northern portion of the state. Alluvial flow or deposits left by rivers washes the sandier particles down into the center portions of the panhandle, and siltier particles flowing to the coast depositing minerals as they settle. The Miccosukee formation is similar but has different textures and particle sizes in the quartz deposits. Knowing where your soils originate will help you understand two major aspects with regard to soil’s physical properties. Those being texture and aggregation.

Soil Texture

Soil, a blend of sand, silt, and clay, is not just the ground you walk on but the very foundation of your garden. These components, deposited in your location through natural processes (as outlined above), have been blended to create a soil unique to your garden. Sand is the largest of these particles, with silt considerably smaller and clay smaller still. This size difference, means there will be air spaces known as pore space within what appears to be a consistent material. These spaces comprise approximately 45% minerals, 25% air, 25% water, and 5% organic matter. Higher sand soils have larger pore spaces which facilitates water flow through that soil profile. What that means for your soil is less water holding capacity and higher losses of nutrients. In contrast, higher clay percentages have smaller pore spaces which coupled with charges at the atomic level are better at holding onto water and nutrients. Understanding your soil texture is key to determining the right timing for irrigation and fertilization while providing insight as to potential aggregation of your soils.

Soil Texture Triangle

Soil Texture Triangle
Photo: USDA

Aggregation

Soil structure is an often overlooked aspect of garden management. Well structured soils resist compaction, hold on to water, and retain plant nutrients. They also provide growth space for roots which have access to the resources they need to fuel healthy plants. Conversely, poor soil structure makes your garden more susceptible to ponding and inhibited plant growth. Soil aggregation is what provides this structure. Aggregation is the conglomeration of soil particles bound through chemical bonds and physical forces bolstered by soil biota. Aggregates form through a few mechanisms both inherent and dynamic. Inherent factors include clay content which form and break with changing moisture levels. Other inherent factors include those minerals inherently present in the soil such as calcium. Dynamic factors include levels of organic matter, and those fauna present in that soil.

Soil structure types

Types of soil structures
credit: USDA/NRCS

Maintaining Healthy Physical Structures

Many Florida soils are poorly structured which is why they need to be properly managed for homeowners to have successful gardens. Before you can begin to improve your soil, you must understand your soil’s story. Start with testing for compaction by pressing a screwdriver into the ground.  If this is difficult, you need to take action to relieve the situation and increase the availability of air in your root zone. Tillage is a good way to do so, but be wary as excessive tilling can lead to higher compaction problems long term. Look into conservation tillage as a methodology to avoid this problem. Perform a jar test to understand the texture of your soil and thus its propensity to develop aggregates. For high sand soils, add organic matter to improve structure. Be careful to add smaller amounts at a time as organic matter has an inherent nutrition load and too much may begin to limit nutrients. Cover crop strategies are a great way to add organic matter while keeping soil covered during non-active growth periods.

Soil improvement and management will take multiple growing seasons. Stick to it and monitor your soil to keep your gardens healthy and thriving. For more information on soil, see these Ask IFAS documents, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.

Daylilies in the Landscape

Daylilies in the Landscape

Overview of Daylilies

Spring has begun, and the flowers are making their debut en masse. The daylily is an exceptionally versatile plant that grows in various colors, shapes, and habitats (Hemerocallis spp.). This plant garners its name from a combination of Greek terms meaning “beauty for a day,” given the tapestry a mass planting provides, they live up to that name. These plants tend to bloom repeatedly for 4-7 weeks, though each individual flower only lasts one day. The time of year flowering begins varies by cultivar, but typically, they may be seen beginning in March, with later bloomers starting around mid-May. Add to their beauty that they are also edible, and you have a plant that can’t be beaten.

UF/IFAS Photo: J. Criss

These perennials are widely available as bare-root or potted plants. Both may be planted in Florida year-round, but planning in spring or autumn will increase success. Inspect roots before you plant them, removing any that are circling or damaged. Plant with the crown at ground level, much like a tree, and keep the soil moist until the plant is established.  Though drought tolerant with deep roots, you’ll still want to apply mulch to retain moisture. Fertilizers may be added in spring, summer, and fall based on soil testing. Scouting this planting is important, but insects rarely cause lasting damage. They may be propagated vegetatively or via seed. Vegetative propagation will become important as these plants fill in spaces over the years and will need to be thinned.

Uses in the Landscape

Thanks to the hybridization efforts of growers worldwide, daylilies are available in every spectrum of color and a variety of flower shapes. Daylilies are clumping plants with grasslike foliage and flowers on a scape that may reach up to 36 inches tall. They can be striking when planted in groups of 10, included in a mixed border, or used to highlight a specific area of your gardens. Because they are so varied, it is important to carefully consider the design elements of your landscape and the growing conditions of your landscape when selecting varieties. All cultivars will require some sun, so avoid heavily shaded areas.

Daylily as a border

UF/IFAS Photo: J. Criss

A Note on Color

Your biggest concern when considering daylilies in the garden will be color. When it comes to landscape design, color integration has three main theories. The first revolves around monochromatic flowering. Simply put, except for the green foliage, all flowers in this type of garden will be one color.  Certainly, daylilies fall into this category, which are often yellow and may be quite striking. The second theory on color in your garden spaces is an analogous scheme in which 3-5 colors on the color wheel are utilized to create continual flow.  In this case, find daylilies with red flowers and pair them with violet or yellow flowers. The final theory on color use in gardens is a complementary scheme. In this instance, colors on opposite sides of the color wheel are utilized. The contrast created by this method can create a striking difference that draws the eye to a specific point. Keep in mind that these are all theories. Ultimately, it is your landscape, and you should use those flower colors which satisfy your sensibilities.

Color Wheel

UF/IFAS: Gail Hansen

Daylilies are a wonderful plant for your landscape. Easy to grow with great variety, few others can compete with them. For more information, see this Ask IFAS document. As always, please contact your local extension agent for additional information on this and any topic regarding your gardens and more.

 

 

 

Integrated Pest Management for Healthy Landscapes

Integrated Pest Management for Healthy Landscapes

The mercury is starting to rise, and the days are getting sunnier. Likely, you are beginning to or have been fantasizing about the potential of your landscape. Visions of multicolored flowers or rows of vegetables lined up waiting to be picked are synonymous with these visions, but they are not free from planning or work. You are not the only one waiting and hoping your gardens become flush with flowers. A veritable army of insects are looking to your landscape for their next meal. Some of these are good, providing critical pollination services, but some seek only to devastate your plants by consuming the leaves or sucking the sap out directly. It’s important to know who these culprits are and to understand the strategies within integrated pest management used to overcome or avoid the damage they bring.    

Aphid nymph
Aphid nymph UF/IFAS Photo: J. Criss

The Bad Guys

First, let’s examine the perpetrators. Insects, like all subdivisions of animals, come in many forms. Those seeking to feast on your plant life are herbivores. They cause damage in several ways, and to understand them, a gardener should start by understanding the mouthparts of these creatures. Damage from chewers such as the Eastern Lubber Grasshopper (Romalea microptera) will be obvious as parts of the leaves will be skeletonized or left with large holes. Others are much more subtle, utilizing hypodermic-style mouths to remove the sugary photosynthates. The damage caused by these insects is much more subtle. It may present as pathogenic, including but not limited to misshaped or discolored leaves, damaged buds, fruit drops, and blackened leaves from sooty mold (Capnodium citri). Insects in this category include stinkbugs (Pentatomoidea) and aphids (Aphidodea). At this stage, you’re probably convinced that gardening in Florida is pointless, but have no fear; there are strategies to overcome these threats.

Scouting

Defending your gardens and landscapes begins with scouting. It seems very simple, but getting into your gardens daily will alert you to burgeoning issues well before they become major concerns. Get out there and look through stems, on the undersides of leaves, and for discoloration. It is much easier to remove leaves covered with stinkbug eggs than the adults once they’ve hatched.

Southern Green Stink bug eggs
Southern Green Stink Bug eggs UF/IFAS Photo: James Castner

First Steps

Next, investigate your gardening practices. Keep plants stress-free with appropriate fertilization and irrigation; these plants will fare better with any insects escaping your scouting efforts. Remove stressed and diseased plants as well as any which have been harvested. This will deny habitat to herbivorous insects. These combined practices are collectively known as cultural controls and are among the best for preventing insect issues. Any insect still appearing through these controls may be removed by hand. This is considered a mechanical control and is the least environmentally taxing, though it is the most labor-intensive methodology.

Ask Nature to Help

Biological controls are next in this hierarchy. Although they may seem confusing, they are nothing more than letting nature take care of itself. This article focuses on herbivores, but the insect world is diverse and includes predatory species. Creatures such as ladybugs (Coccinellidae) and lacewings (Chrysoperia sp.) actively hunt and consume those pests in your gardens, keeping you from this task. This method is not limited to Insects.  Numerous animals, such as frogs, birds, nematodes, and even household pets, can fill this role. Fungi and bacteria have also been found to fill this role, as anyone who has applied Bacillus thuringiensis, commonly called BT, has discovered. This control method is the most environmentally friendly and involves the least amount of physical labor.

Green lacewing
Green Lacewing UF/IFAS photo

Chemical use in Landscapes

Finally, chemical controls are a viable method to control insects in your landscape. These should be used as a last resort when the controls listed above are just not working. When used, make sure you follow the label provided on the product you’ve purchased and that it is the appropriate product designed to control your specific pest. The concern with this control is that pest species may adapt to the chemical, thus rendering it ineffective. When applied, ensure it is done minimally, both in volume and across square footage thus minimizing risk to off-target species.

Controlling pests in your garden can seem a daunting task. The multipronged approach utilizing the above control methods is known as integrated pest management.  Following this methodology will keep your plants pest free and your landscape healthy.  For more information on integrated pest management, see these Ask IFAS documents, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.

Herb Gardens: A Tasty Way to Learn

Herb Gardens: A Tasty Way to Learn

As spring approaches, the time to plan and implement gardens is at hand. If you have wanted to get into this hobby but have been intimidated by the avalanche of information, consider an herb garden. This collection of plants is grown primarily for their aromatic properties and culinary use but are robust making them optimal for getting your feet wet in gardening. They may be grown in a variety of spaces including in-ground, containers, and as companion plants in existing gardens. They are very forgiving with similar growth condition requirements and may be propagated easily from cuttings or seeds. Moreover, herbs have a place in supporting the beneficial insects in your landscape.

What is an Herb, and How do they Grow                            

Herb is a broad term applied to a group of plants whose leaves or stems are used for various purposes. This is an important distinction as they must be differentiated from spices, which find their origins in a plant’s non-leafy structures. It is important to note that some plants, such as cilantro, may be considered both. In this case, the leaves are a culinary herb, but the seeds are a spice called coriander. These are subtle, but important distinctions.

Many culinary herbs fall into the Lamiaceae family, commonly called the mint family. They run the gamut of life cycles as annuals, biennials, and perennials giving the grower a range of plants from which to choose. You’ll do best by mixing these life cycles to optimize successional plantings to provide a constant supply of herbs for your kitchen.

As with all gardening, everything begins with soil testing. Knowing the pH and texture of your soil will inform your management practices. Aim for a slightly acidic soil with a pH of around 6.5 and a loamy texture. I can hear you all out there, what does loamy texture mean? Soil consists of sand, silt, and clay.  Loamy refers to soil with an equal proportion of these particles. It is desirable in gardening as it lends to a balance of moisture retention and drainage while providing nutrient-holding capability. These are desirable traits for any growth medium.

What Herbs Should I Grow

At this point, you are probably getting anxious for me to tell you what the easiest herbs to grow happen to be. Below are three herbs that will make you wonder why you delayed entering into this hobby.

One of the easiest and most useful is rosemary (Salvia rosmarinus). This woody perennial is drought tolerant and pest resistant, making it wonderful for new and old gardeners. It prefers well-drained soil and may need some protection in the winter. This plant is easy to shape and propagates best via cutting. Rosemary flowers in the winter to spring time frame serving as an early season support for pollinators such as bees. Plant this herb in the spring, and be sure not to overwater or use too much fertilizer.

Rosemary bush
UF/IFAS Photo: J. Criss
Rosemary Flower
UF/IFAS Photo: J. Criss

Basil (Ocimum spp.) comes in a wide variety of cultivars. The wide selection is likely due to this herb’s presence in multiple cultures covering at least three continents. This herbaceous annual prefers morning sun with some afternoon shade and well-draining soil. Plant from seed or cutting after the last chance for frost has passed. Harvest leaves for culinary use and keep the plant in vegetative growth by pinching the flower stalks through the summer. Once you’ve had all you need for the year, go ahead and let the flowers bloom. Pollinators will swarm these plants, and you will receive all the seeds you need for next year’s planting.

African Blue Basil
UF/IFAS Photo: J. Criss

Finally, among the easily grown herbs is oregano. This herb is split into two main cultivars in Mexican oregano (Lippia graveolens) and European oregano (Origanum vulgare). They differ in taste but are often used the same way. This herb prefers full sun and is a hardy perennial that will self seed. It may be propagated from cutting, seed, or division.

Oregano in the Santa Rosa Extension Garden
UF/IFAS Photo: J. Criss

Those outlined here are but a few of the options for herb gardens. Herbs are a wonderful way to get your feet wet in gardening. Being easy to grow and propagate, they will provide a masterclass in plant care and flavorings for your dinner. Use herbs in your garden to feed yourself, as a pollinator benefit, or to attract predatory insects to your garden. For more information on herb gardens, see these Ask IFAS documents, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.

Potato: A Lot of Tuber in a Little Space

Potato: A Lot of Tuber in a Little Space

Looking to add a nutritional powerhouse to your early season garden this year? One plant that is often thought to be difficult to grow in Florida will surprise many home gardeners. This plant has a long, storied history, having been introduced extensively worldwide, and has invigorated and decimated entire populations. I speak, of course, of the humble potato (Solanum tuberosum), which performs well in our cooler North Florida winter. This member of the Solanaceae or nightshade family can trace its origins to the Andes mountains, where it was discovered by European settlers and brought back to their countries of origin. From there, the potato found success as a food crop and was reintroduced worldwide. This tuber is a big producer, and worthy of a spot in your home garden.

Varieties

The first objective with potatoes is to find a variety that will perform well in our sandy soils and climate. Russets are thought to be the gold standard in potatoes, and while some may be suitable, they are not optimal for Florida gardens. Instead look for some of the later entrants to this market. Several white and red varieties are available which mature quickly and can tolerate environmental conditions in the panhandle. White varieties suitable for this region are ‘Lachipper’ and ‘Sebago’, while the red varieties known to do well here are ‘Red Lasoda’ and ‘LaRouge’. These are compatible with our environment and as such perform well here.

Potato varieties
UF/IFAS photo: C. Hutchinson

Growth Practices

A well-draining, slightly acidic, and loose soil will provide the best environment for maximum yield. As with all gardening, it’s best to have your soil tested well before you plant and make any pH adjustments required early. Potatoes grow from “seed” which are essentially smaller potatoes grown specifically to produce more plants. It’s best to acquire these from a reputable seller and avoid grocery store leftovers, as their variety and disease resistance is questionable. Growth happens from the “eye” of the seed, which may be planted with or without growing roots.  Cut the seeds into smaller pieces, ensuring there is at least one eye per piece, and allow them to sit in a cool, dark environment for a few days to callous over. They are now ready to plant and should be four inches deep, spaced eight inches apart in three-foot rows. Potatoes require two fertilizer applications, emphasizing nitrogen and potassium specifically, as these pass through the soil easily with irrigation. Apply half of the fertilizer at planting with another application approximately 30-40 days later. Application rates vary and are based on yield goals as well as soil test results so check with your local extension agent to discuss application rates. Keep the potatoes evenly moist but make sure not to flood the rows. Finally, there is a unique methodology with potatoes in that you’ll need to add soil to the top of the row when the potatoes poke through. This is called hilling and is crucial to keep the tubers from turning green and producing a toxin known as solanine.

Potato plant with tubers
UF/IFAS photo: C. Christensen

Harvest Time

Your potatoes should be harvestable in about 90-105 days, depending on variety and environmental factors. You’ll be able to tell the plant has matured as the vines will begin to die back naturally. Modern practices have augmented this to include a vine kill which may be performed mechanically or through chemical application. This will force the tubers to mature, allowing the gardener greater control of harvest times and helping to avoid the risk of late-season pathogens. Vine kills are performed between 80-90 days after planting with tubers remaining in the ground for an additional 21 days. All of these time frames are dependent on variety but will produce a more usable and easy-to-store tuber.    

Potatoes after digging
UF/IFAS photo: C. Christensen

Potatoes are a worthy addition to the garden and can provide a lot of nutrient-dense food in a small space. There are a few tricks to growing these tubers, but for what they give back, you’ll find it a very rewarding experience.  For more information, see these Ask IFAS documents. As always, please contact your local extension agent for additional information on this and any topic regarding your gardens and more.