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.
Our winter season is a good time to install many trees and shrubs. Here is a basic review of a few planting practices to make sure that your new plants get off to the good start.
As we eagerly anticipate the arrival of spring, it’s the perfect time to begin thinking about planning your garden. A key thing to do to help prep yourself is starting your seeds. Whether you’re a seasoned gardener or just beginning, having the right tools and supplies is crucial for garden success.
Photo Credit: Tyler Jones, UF/IFAS
Seed Trays and Containers
If you are intending to start seeds to plant between February and March, you will need to obtain seed trays or containers to germinate your seeds. Seed trays can come in different shapes and sizes, allowing you to accommodate for different types of seeds. When you have selected what seeds you are planting for this year, you will need to follow the seeding rates and spacing measurements on the back of the seed packet. You want to opt for a tray that has proper drainage to prevent any type of waterlogging, but still keeps some moisture to support seed germination. You will need a quality seed starting mix to create a strong foundation for your seeds to germinate in. Using a light weight media that will allow airflow is also important. When planting your seeds in the tray, smaller seeds can be broadcasted over the surface of your soil media and larger seeds will need to be covered.
Example of a seed tray. Photo Credit: Terri Keith, UF/IFAS Extension Jackson County
Temperature & Humidity
Correct temperatures and humidity are both very important for successful germination of your seeds. Some trays come with a clear plastic cover or “dome” to help regulate the temperature and the humidity in the soil media. This creates a “greenhouse” effect for your seeds. If you are having trouble controlling the humidity, you may consider poking holes in the cover if there is too much moisture in the soil media. Once the humidity is controlled, cover the holes with clear tape.
Your seeds will need warmer temperatures to aid the process of germination. A tool you might consider investing in is a heat mat. The heat mat lays underneath the seed tray and helps provide warm temperatures consistently during the day and night, keeping the soil media warm enough to allow the seeds to germinate properly. Most heat mats are electrical and will need to be plugged in, so starting your seeds indoors may be a better option during January and February. After the seeds have germinated and have grown to about 2 inches high, they will need to be thinned out and transplanted to a bigger container until the time is right to transplant them to your garden.
Organization
When planning any type of project, it is always important to stay organized. If you are planting different kinds of seeds in one tray, using labels to know which seeds were planted will help you after the transplants have grown to their desired height. Once you have planted all the seeds that will be used, storing them correctly for the next season is vital. Storing them in a temperature controlled environment that is free from excess moisture is crucial so that they stay viable for the next season. It is also important to keep stored seeds labeled with the packet they came from to know spacing and number of days to harvest for the coming year.
Arming yourself with the necessary tools and knowledge is essential to nurture your seeds into thriving plants. Whether you’re cultivating a windowsill garden or preparing for an outdoor oasis, knowing the key steps to starting your seeds will lay the groundwork for a great harvest.
Article Written by Khadejah Scott, Horticulture & Ag/Natural Resources Agent, UF/IFAS Extension – Wakulla County
In the serene charm of winter, a beautiful flower comes to life, adding its beautiful blooms to gardens everywhere – the Camellia, often hailed as the “Rose of Winter.” Adorned with lush, glossy evergreen leaves and a tendency to bloom even when other plants are dormant, the Camellia showcases nature’s enduring strength and grace. Consider choosing and planting camellias this January to bring this touch of elegance to your own garden.
Camellia flowers. Photo by Marisol Amador, UF IFAS
Description: Originally from Asia, camellia plants first arrived in America in 1797 and were grown in greenhouses in New England. For over two centuries, they have proven to be reliable and valuable additions to the southern landscape. Their leaves are simple, thick, serrated (notched like a saw), alternately oriented, and usually glossy. These plants produce large, multicolored flowers that can grow up to 5 inches. The common name “camellia” refers to hybrids of Camellia japonica and Camellia sasanqua. Sasanqua types bloom from October to December, followed by japonica types, which bloom from December to March.
Landscape Uses: Camellias stand out when few other plants bloom in the fall and winter. Camellia blooms look similar to roses, as well as anemones and peonies. The rest of the year, camellias make excellent landscaping plants due to their glossy, evergreen foliage, intriguing patterns and textures, and low maintenance requirements. Camellias can be used as foundation plantings, screens, accent plants, background groupings, and hedges in the landscape. Mass plantings or clusters can yield the most significant benefit.
Photo by UF IFAS
Plant Selection: You can buy camellias from nurseries, plant sales, garden festivals, and camellia displays. Plant size and form vary significantly among varieties, ranging from small to big, spreading to upright. There is also a great variety of flower shapes, hues, and conditions, and new types are released yearly. A comprehensive list with descriptions and images is available from the American Camellia Society (https://www.americancamellias.com/care-culture-resources).
Care: To ensure the longevity of your camellias, choose a suitable location with bright, partial shade, protecting them from intense afternoon sun. Plant between November and February for optimal root establishment before summer. Use mulch to retain moisture and stabilize temperature fluctuations. Camellias thrive in well-drained, fertile soil with a pH between 5.0 and 6.5. While generally resistant to drought, consistent watering is necessary during prolonged dry periods. Apply acid-forming fertilizer twice a year, and prune lightly in early spring if needed.
Ultimately, camellias stand as enduring botanical treasures and timeless landscape companions. For more information about camellias, contact your local county extension office.
In the late 1700’s, explorer and naturalist William Bartram and his father, the “King’s Botanist”—visited Pensacola and much of the southeastern United States. Curious observers of everything from plant growth and wildlife to Native American culture, they were also collectors. Countless American plant species were sent to Europe for further examination and later preserved in gardens and arboretums.
The Franklin tree no longer grows in the wild, but was originally discovered and named in the late 18th century near this spot in coastal Georgia. Photo credit: Carrie Stevenson, UF IFAS Extension
If it were not for their formidable observation skills, at least one species of unique native tree would be completely extinct. While traveling along the Georgia coast in 1765, the Bartrams recorded and named a species of small tree they’d never seen anywhere before. They christened it the “Franklin tree” for their friend and compatriot Benjamin Franklin. Known scientifically as Franklinia alatamaha (after Franklin and the nearby Altamaha River), its similarity to the loblolly bay tree landed it in the Gordonia genus for a while. References in the literature to this tree may include Gordonia alatamaha, Gordonia pubescens var. subglabra, or Lacathea florida, although it is now officially Franklinia alatamaha and considered part of the tea tree family.
The attractive bloom of the Franklin tree is reminiscent of magnolia flowers. Photo credit: Scott Zona, used with permission from NCSU Extension
William Bartram knew this species was unique, as he never saw the tree elsewhere in any of his extensive travels. He returned to the area in 1776, this time collecting seeds from the Franklin trees and propagating five of them successfully back at his home in Pennsylvania. The last time this species was seen in the wild was at the original wetland floodplain along the Altamaha River between 1790-1803. Now, the only Franklin trees in existence are all descendants of the seeds collected by William Bartram.
A sign in the Brunswick, GA marine extension office/demonstration garden explains the tree’s unique history. Photo credit: Carrie Stevenson, UF IFAS Extension
Their exact cause of extinction is not clear, but there are some solid theories. Land adjacent to the river was cleared for cotton farms, and the Franklin trees were vulnerable to a fungal pathogen that affects cotton. Based on the early records, the very small endemic population was particularly susceptible to habitat destruction and changing climatic conditions.
While no longer growing in the wild, the tree is mostly living in demonstration gardens and Arboretums on the east coast. However, it can be found in the nursery trade and grown in a large swath of the country if cared for properly. I was introduced to this species for the first time at the Brunswick, Georgia marine extension office. In addition to working with fishermen, they also educate residents on native landscaping and ways to prevent stormwater runoff and pollution. Over a span of a few years, they transformed the “front yard” of their office building from a turf lawn with a couple of oaks to a lush landscape full of flowers, shrubs, and pollinator insects. Included is a Franklin tree, with signage explaining its unique history. At about 15-20 feet tall, it has reached mature height. The original site of the Bartrams’ discovery is less than 20 miles from the garden location.
Just a few years ago, this lush garden consisted only of turf grass and a few live oak trees! Photo credit: Carrie Stevenson, UF IFAS Extension
