When a pea seed germinates, it goes through a series of stages: imbibition, activation of enzymes, and radicle and root emergence. Photo by Bogdan Wankowicz, Adobe Stock.
The Science of Germination
Navigating through a few recent hard freezes, the Florida Panhandle’s winter still holds its grip, but a shift is anticipated. As we transition into February and March, the temperatures are likely to soften, offering a milder embrace. Amidst this change, many gardeners eagerly anticipate the surge of new life. This phenomenon is deeply intertwined with the captivating science of germination. It is indeed an intricate process that transforms a dormant seed into a thriving plant.
The Germination Process
Tomato seedlings initially produce cotyledons, serving as temporary nutrient sources, followed by the emergence of true leaves, which engage in photosynthesis and mark the onset of lateral branching. Photo by Baharlou, Adobe Stock.
Germination is when a seed transforms into a seedling, ready to emerge from the soil. But what exactly is happening during this process?
Germination commences with the absorption of water, also known as imbibition. As water is absorbed, the seed swells, softening the seed coat and paving the way for the emergence of the embryo. This pivotal step activates enzymes within the seed, kickstarting the breakdown of stored nutrients, such as starches, into simpler forms like sugars. These nutrients serve as the fuel for the growing embryo until it can harness energy from the sun through photosynthesis.
The first visible sign of this process is the emergence of the radicle, the embryonic root that anchors the plant and facilitates water and nutrient absorption from the soil, establishing a solid foundation for growth. Following radicle development, the embryonic stem begins its upward journey, accompanied by the emergence of cotyledons, or seed leaves, that aid in nutrient storage during the initial stages of growth.
With the growth of leaves, the seedling gains the ability to engage in photosynthesis. This transformative process allows the plant to convert sunlight into energy, fueling further growth and development. The root system continues to expand and branch out, enhancing stability and enabling the plant to absorb water and essential nutrients from the soil.
As the plant progresses through stages of growth, it eventually matures to produce flowers and seeds, completing the life cycle. These seeds, in turn, hold the potential to initiate the germination process anew, perpetuating the cycle of growth and renewal.
Temperature’s Role in Successful Germination
Get a jump start on the spring gardening season by using full spectrum grow lights and heat mats to germinate and grow warm season crops, like tomatoes, indoors. Photo by Molly Jameson.
Temperature is a critical factor influencing the success of germination, serving as a cue for enzymes to initiate their performance. Seeds exhibit distinct temperature preferences, affecting both the likelihood and speed of germination. Understanding these preferences is essential for a thriving garden.
While some seeds, like peppers and tomatoes, flourish in warmer conditions, others, such as lettuce and spinach, prefer cooler environments. It’s crucial to identify the ideal temperature range for your chosen seeds to ensure successful germination. When planning your garden, closely monitor soil temperature and sow seeds at the appropriate time to align with their preferences. For instance, if you’re starting warm season seeds like tomatoes in winter, consider investing in heat mats, a greenhouse, or indoor full spectrum grow lights to maintain a consistent and favorable temperature for germination.
Optimizing germination and ensuring a successful start for your garden hinges on understanding the specific temperature preferences of your crops. Temperature not only influences whether a seed will germinate but also plays a significant role in determining the speed of germination, providing a valuable head start when appropriately managed.
Chilling Requirements for Some Seeds
Echinacea purpurea (purple coneflowers) benefits from cold stratification, a process that involves exposing seeds to cold conditions to break their dormancy and promote germination. Photo by Orestligetka, Adobe Stock.
Some seeds, like black-eyed Susan (Rudbeckia hirta) and purple coneflower (Echinacea purpurea), exhibit a preference for a winter chill through a process known as stratification. This involves exposing seeds to cold temperatures before planting. It mimics the conditions these seeds would experience in their native habitats, breaking dormancy and promoting successful germination. If you’re growing seeds that benefit from cold stratification, consider simulating winter conditions by freezing them for at least a month before planting. Additionally, certain seeds benefit from wet stratification, where they are kept moist during the cold treatment.
While stratification is more commonly associated with perennial flowers and woody plants, there are some vegetable seeds that can also benefit from cold treatment. Carrots and beets may experience improved germination rates with a brief period of cold stratification. Keep in mind that while these vegetables may benefit from stratification, it’s not always necessary for successful germination. Many vegetable seeds are adapted to germinate without a cold treatment.
As we anticipate the arrival of spring, let’s not just see seeds as tiny dormant entities but as intricate biochemical wonders waiting to unfold. Germination is not merely a biological process; it is a testament to the resilience and adaptability of life. It is a reminder of the interconnectedness of all living things and the perpetual cycle of growth and renewal that defines the plant kingdom here on Earth.
Vermicomposting is an eco-friendly method for recycling organic waste, improving soil fertility, and boosting plant health. Photo by UF/IFAS.
In a world increasingly focused on sustainability, vermicomposting has quietly emerged as a simple, eco-friendly method to reduce waste and enhance garden soil health. This natural process involves specialized earthworms that convert kitchen and garden waste into nutrient-rich vermicompost, often dubbed “black gold.”
Beyond the environmental benefits, vermicomposting brings tangible advantages to your garden. When integrated into your garden soil, vermicompost enhances soil structure, improving water retention and reducing soil compaction. Moreover, it serves as a slow-release fertilizer, converting nutrients into readily available forms for plant roots. Vermicompost also enriches your soil ecosystem by introducing beneficial microorganisms that help suppress soil-borne pathogens, fostering a healthy environment for your garden and landscape plants.
Finished vermicompost has a crumbly, earthy texture that enhances soil structure, improving its water retention and aeration properties for healthier, more resilient plants. Photo by UF/IFAS.
Below is a summary of the components needed to successfully vermicompost at home.
Worm Bin: Choose a dark-colored, breathable bin that is no deeper than 20 inches. The size of your bin should align with the amount of food waste you produce weekly. As a general guideline, you’ll need approximately 1 sq. ft. of surface area for every pound of weekly food waste. If you’re building a vertical system, consider using three 10-gallon bins, which work well for this purpose.
Worms: You’ll need approximately 1 lb. of Eisenia fetida worm species, which equates to about 1,000 worms, for every 1 sq. ft. of surface area in your bin.
Bedding: Choose moistened carbon-rich organic materials such as newspaper strips with plant-based ink, leaf litter, shredded corrugated cardboard, or coir for bedding. Fill the bin about one-third full of bedding or create a layer no thicker than 6 inches.
Grit: To aid in digestion, mix in one handful of regular soil when you’re starting a new bin.
Food: Worms have a taste for chopped vegetable scraps and most fruits, as well as coffee filters/grounds, leaves, crushed eggshells, and plain grains. As your worm population becomes established, begin feeding them slowly and ensure the food is being consumed before adding more. Smaller food pieces, with greater surface area, are easier for worms to digest. In general, 1 lb. of worms can consume roughly 1/3 lb. of food per day once they are well-established.
Start your fall garden seeds in containers to give them a healthy head start. Photo by Molly Jameson.Seed veggies into starter cell flats using a fine-textured growing medium designed to support seed germination and early seedling development. Photo by Molly Jameson.
Step-by-Step Instructions: Indirect Seeding Fall Veggies
While summer gardens offer a variety of intriguing fruiting crops, I have a special fondness for gardening during the fall season. This preference stems from the reduced pest pressure, decreased need for watering, fewer weeds, and the more favorable cooler temperatures for completing gardening tasks. Although it generally offers a more straightforward gardening experience, achieving success with your fall garden still hinges on applying the right techniques, with one crucial aspect being the care for seeds and young seedlings.
Indirect seeding allows you to nurture your seedlings before they establish their permanent residence in your garden, ensuring their growth into robust, mature plants. Below, you’ll discover a step-by-step guide to indirect seeding and planting for fall vegetables. By following these instructions, you’ll get a head start in cultivating a thriving fall garden that will delight your taste buds.
Seeding into Starter Cells:
While many crops can be started indirectly in starter cells, it’s important to note that root vegetables (such as beets, carrots, radishes, turnips, etc.), peas, and beans are exceptions due to their delicate root systems, which do not transplant well. These particular crops thrive when directly seeded into the garden. Conversely, fall crops that typically benefit from indoor seeding include Brussels sprouts, broccoli, cabbage, cauliflower, cilantro, kale, lettuce, mustards, parsley, spinach, and Swiss chard. For Florida planting dates, transplant ability, and other detailed planting information, see Table 1 in the UF/IFAS publication Florida Vegetable Gardening Guide.
If you use fluorescent grow lights, maintain 2 to 4 inches between the top of the seedlings’ canopy and the fluorescent bulbs. Photo by Molly Jameson.
Begin by moistening a starting mix, which is any fine-textured growing medium designed to support seed germination and early seedling development. Fill seed starter cells with this prepared mix, ensuring a level, flat surface.
Create shallow indentations (2-3 times the diameter of the seed) in the starting mix in each starter cell using your finger and place 1-2 seeds in each cell. (Remove all but the strongest seedling if multiple seeds germinate in the same cell.)
To ensure even coverage and prevent clumping, lightly sprinkle dry starting mix over the seeds.
Label with the crop name, variety, and date.
Mist the surface with water from a spray bottle, pump sprayer, or a hose spray nozzle. Maintain moisture levels, avoiding waterlogging.
Before the seeds germinate, keep them in a temperature-controlled room or out of direct sunlight. Germination time varies, but typically takes 5 to 14 days, depending on the crop, environmental conditions, and seed quality. (For fall varieties, germination is best between 50-80°F.)
As soon as seedlings emerge, move them to a sunny location with more than 6 hours of direct sunlight. If temperatures exceed 85°F, provide afternoon shade to protect them from intense heat. If using full spectrum grow lights indoors (such as a T5 fluorescent light fixture), place seed starter cells at a distance of 2 to 4 inches between the top of the seedlings’ canopy and the fluorescent bulbs for 14 to 16 hours a day.
Continue to keep the starting mix moist but not waterlogged.
Up-potting into Larger Pots:
Up-potting refers to transplanting a young plant or seedling from a smaller container or pot into a larger one. While up-potting most seedling crop varieties into larger pots before transplanting into the garden is beneficial, you can skip this step and directly transplant seedlings from the starter cells into the garden if conditions are favorable (maximum air temperature is less than 86°F). However, keep in mind that young seedlings may be more vulnerable to rain, wind, insects, and animal disturbances. Up-potting into larger pots with nutrient-rich potting mix offers better protection and more time for root development.
When up-potting, carefully extract each seedling using a butter knife to avoid disturbing the roots. Photos by Molly Jameson.
When seedlings develop “true leaves” (the second set of leaves after the initial seedling leaves), it is time to transfer them into larger pots (2″-4″ wide).
To start, fill the larger pots about halfway with pre-moistened, nutrient-rich potting mix designed for vegetables, ensuring good drainage.
After thoroughly watering the small seedlings, carefully extract each from the starter cells, using a butter knife for gentle and precise removal to avoid disturbing the roots.
Being careful not to disturb the roots, place each seedling gently into their halfway-filled pot and add more potting mix until the seedling is secure, standing upright, with all roots covered. There should only be one seedling per pot.
Keep seedlings in a sunny location with more than 6 hours of direct sunlight. If temperatures exceed 85°F, provide afternoon shade to protect them from intense heat. If using full spectrum grow lights indoors (such as a T5 fluorescent light fixture), place seedlings at a distance of 4 to 6 inches between the top of the seedlings’ canopy and the fluorescent bulbs for 12 to 14 hours a day.
Continue to keep the potting soil moist but not waterlogged.
Transplanting into the Garden:
When the time is right, dig a small hole in the garden bed and place the plant, along with the potting mix, in the hole, following the crop-specific spacing requirements. Photo by Molly Jameson.
Once the plants have developed strong roots and reach about the height of their pots, they are ready for transplantation into the garden.
If the plants have been indoors under grow lights, allow them to “harden-off” by gradually exposing them to outdoor conditions for a week. This helps them adjust to wind, direct sunlight, and varying temperatures.
Prepare the garden bed with compost and other soil amendments.
Water the plants thoroughly before carefully removing them from their pots, ensuring minimal disruption to the roots.
For each plant, dig a small hole in the garden bed and place the plant, along with the potting mix, in the hole, following the crop-specific spacing requirements (see Table 1 in the UF/IFAS publication Florida Vegetable Gardening Guide).
Cover the roots and maintain consistent soil moisture, avoiding waterlogging.
In summary, mastering the art of indirect seeding and planting fall vegetables can greatly improve your chance of a successful harvest. From carefully sowing your seeds in starter cells to up-potting and ultimately transplanting into your garden, each step is a vital component of the process. So, roll up your sleeves, get your hands dirty, and witness your fall garden flourish. Happy gardening!
Fall is just around the corner, and that means it is time to start kale and collards, root vegetables, and salad greens. Photo by Rachel Mathes.
In spite of this record-breaking hot summer, it might be surprising to realize that we are just a month away from the onset of fall. As the sun-soaked dog days gradually relinquish their hold to the inviting coolness of autumn, the allure of the new season comes into view.
If your thoughts are already conjuring images of vibrant leaves and the anticipation of robust greens and earthy root vegetables in your garden, we extend an invitation to explore our newly revamped edition of the North Florida Vegetable Gardening Guide.
We’ve transformed the guide from a static PDF into a user-friendly website, making it easier than ever for you to tap into its wealth of gardening insights. Crafted by the adept hands of the UF/IFAS Leon County Extension, this guide serves as an invaluable resource catering to both seasoned horticulturists and aspiring gardeners.
Dive into an array of articles, planting schedules, images, and informative UF/IFAS EDIS publications – all thoughtfully designed to address your gardening questions. From the basics of getting started to the finer points of site selection, pest management, fostering biodiversity, soil testing, composting, harnessing cover crops, and mastering irrigation techniques – the North Florida Vegetable Gardening Guide website has it all covered.
For those who prefer a tactile experience, physical copies are available upon request at the UF/IFAS Leon County Extension Office, located at 615 Paul Russell Rd., Tallahassee, FL 32301. A quick call ahead will help you ensure availability.
We’re also excited to announce our upcoming Fall 2023 Backyard Gardening Series, set for September 6 and 13, from 6:00 to 8:00 p.m. on both evenings at the Leon County Extension Office (615 Paul Russell Road).
If you’re eager to explore the art of fall gardening in depth, this series will cover topics like site selection, soil enrichment, effective fall planting techniques, and more, including a hands-on planting activity.
Individual tickets are available for $10 per person if pre-paid online or $15 in cash or check at the door. For families of three to four, pre-paid online family tickets are $20 per family or $30 in cash or check at the door. This registration fee includes both evenings on September 6 and 13 and light refreshments will be provided.
For any further inquiries, please contact Molly Jameson at mjameson@ufl.edu or via phone at 850-606-5200.
Flint corn is one of the oldest varieties of corn and has been cultivated by Native American tribes for thousands of years. Photo by Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org.
The Ancient Journey of Native Vegetables
The Americas are not only a land of beautiful landscapes and diverse cultures but also the birthplace of a remarkable array of indigenous plant species. Native vegetables have played a significant role in shaping the culinary traditions, cultural practices, and biodiversity of the region. To truly appreciate their significance, it is important to delve into their fascinating history and observe how they have evolved over time.
The cultivation of vegetables in North America, Central America, South America, and the Caribbean dates back thousands of years, with evidence of early farming practices emerging in Mesoamerica (central Mexico southward through Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica) around 9,000 BCE (Before Common Era), or about 11,000 years ago. Native peoples, including indigenous tribes, recognized the value of native plant species and skillfully cultivated them to meet their nutritional needs. Through trial and error, they learned to adapt and enhance the growth of these vegetables, setting the foundation for the crops we know today.
Squash has been an important agricultural crop for thousands of years. Photo by Howard F. Schwartz, Colorado State University, Bugwood.org.
Maize. Maize (Zea mays), or corn, holds a central place in the history of American agriculture. It is believed to have originated from a wild grass called teosinte, which had few small, hard kernels enclosed in a tough husk. It was much smaller than the corn we know today and was barely edible, tasting more like a raw dried potato, with only a few hard kernels per ear. Ancient societies in present-day Mexico began domesticating maize 9,000 to 10,000 years ago, selectively breeding it to produce a variety of colors, sizes, and textures. Maize quickly became a staple crop, providing sustenance and shaping the cultural and economic practices of many indigenous civilizations, such as the Mayans and the Aztecs. Over time, its cultivation gradually spread northward, reaching present-day United States and Canada.
Squash. Squash (Cucurbita spp.) holds a significant place in the ancient history of the Americas, with evidence of its domestication dating back approximately 8,000 to 10,000 years ago. Native peoples in various regions, including Mesoamerica and North America, recognized the value of the flesh and seeds of squash as versatile and nutritious food sources. Domestication involved selecting and cultivating wild squash varieties with desirable traits, leading to the development of different cultivated squash varieties such as acorn, delicata, butternut, and zucchini.
The colorful seeds of Anasazi beans, named after the Anasazi Native American tribe who inhabited the Four Corners region of the United States from about 200 BCE to 1300 CE. Photo by Howard F. Schwartz, Colorado State University, Bugwood.org.
Beans. Common beans (Phaseolus spp.) have a rich and ancient history in the Americas, with evidence of their domestication dating back around 7,000 to 8,000 years in the region that is now Peru. Native peoples in Mesoamerica and the Andean region recognized the nutritional value and versatility of beans, incorporating them into their agricultural practices. Cultivated by civilizations such as the Maya, Aztecs, and Inca, beans were an essential staple crop alongside maize and squash. The domestication of beans allowed for the cultivation of various species, including kidney, lima, and black beans.
The Three Sisters. The “Three Sisters” have deep historical roots in ancient American agriculture, with evidence of their use over 7,000 years ago. This system, practiced by various indigenous civilizations, especially in Mesoamerica and North America, involved the intercropping of three key crops: maize, beans, and squash. Maize served as the central component, providing a tall stalk for the beans to climb. Beans enriched the soil with nitrogen through their symbiotic relationship with bacteria, allowing them to convert atmospheric nitrogen into a form that the plants can utilize. Squash, with its broad leaves, acted as a living mulch, reducing weeds and retaining soil moisture.
The Three Sisters synergistic trio enhanced soil fertility, prevented erosion, and yielded a nutritionally balanced diet for generations of indigenous communities. It also fostered a deep connection between humans and the land, emphasizing a holistic approach to farming that honored the interdependence of crops and the environment.
Despite their notoriety in Ireland, potatoes originated in the Andean region of South America. Photo by Edward Sikora, Auburn University, Bugwood.org.
Potatoes. While potatoes (Solanum tuberosum) are commonly associated with Ireland, they actually originated in the Andean region of South America, what is now Peru and Bolivia, between 7,000 to 10,000 years ago. Long before European arrival, Native Americans were cultivating potatoes. Over time, they developed different varieties of potatoes, adapting them to suit various climates and growing conditions. It wasn’t until the exploration and colonization of the New World in the 16th century that potatoes were introduced to Europe, eventually becoming a staple food crop there.
Tomatoes. Similar to the association of potatoes with Ireland, tomatoes (Solanum lycopersicum) are often associated with Italian cuisine, including pasta sauces and pizza. And like potatoes, tomatoes also have an ancient history in the Americas, with evidence of their domestication dating back about 7,000 years. Native to western South America, particularly in the region that is now Peru and Ecuador, wild tomato species were cultivated by indigenous civilizations. Initially, tomatoes were smaller and had a more varied range of colors beyond red, including yellow and purple. Through years of selective breeding and cultivation, larger red varieties became more prevalent. Over time, the ancient Mesoamerican civilizations to the north, such as the Maya and Aztecs, adopted tomatoes into their agriculture and diet. Following the European colonization of the Americas, tomatoes were introduced to other parts of the world in the 16th and 17th centuries, where their popularity and cultivation spread widely.
Habanero peppers are believed to have originated in the Yucatan Peninsula of Mexico and have been cultivated for centuries. Photo by Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org.
Peppers. Peppers (Capsicum spp.), or chili peppers, also originated in the Americas, specifically in regions that now belong to Mexico, Peru, and Bolivia. They were domesticated around 6,000 years ago and played significant roles in the cultures and diets of ancient civilizations like the Aztecs and Mayans. Peppers were introduced to other parts of the world through the exploration and trade routes of Spanish and Portuguese explorers. They played a significant role in spreading peppers to Europe, Asia, and Africa during the 15th and 16th centuries.
Some Other American Crops. There is a rich variety of lesser-known crops that originated in the Americas as well. Amaranth and quinoa, originating from the Andean region, are highly nutritious, rich in protein and essential amino acids. Chia seeds, native to Central and South America, have many culinary uses. Yucca, a traditional starchy root vegetable, has been cultivated in tropical regions for centuries. Fruits such as guava, papaya, and passion fruit originated from the Americas and have unique flavor profiles. Finally, the sunchoke, also known as Jerusalem artichoke, is a North American root vegetable known for its nutty taste and abundant dietary fiber.
The ancient journey of native vegetables in the Americas highlights their significance in shaping agriculture, culture, and nutrition. By embracing this ancient journey, we not only honor the wisdom and traditions of indigenous communities but also ensure a sustainable and inclusive future where diverse crops and food systems thrive, preserving the rich biodiversity and cultural legacy for generations to come.
