Winter is probably the easiest time of year to kill the plant you brought in from the cold. And, the fastest way is by overwatering. Grueling growing conditions like lower light levels, dry air, shorter days and chilly temperatures really stress out plants, which makes them susceptible to insect and disease problems. Then the pests finish them off.
The secret to helping plants survive winter is adjusting care routines to suit seasonal growing conditions. Here are a few things to consider.
Light
In winter, the sun is lower in the sky and light levels near windows drop up to 50 percent. Houseplants that grow near a sunny eastern or northern window in summer may need a southern or western exposure in winter. Likewise, tropical plants that were able to withstand direct sun outside will need to be in the brightest spots possible or may require extra lighting inside. Plants are likely to lose leaves in order to adjust to the light change. The new leaves that grow back will be accustomed to the lower light. Remember that if those plants are going back outside in the spring. They will need to be shaded for a while or the new leaves will sunburn.
To help plants cope with changing light levels:
Move plants closer to windows, if possible.
Clean windows to allow maximum light transmission.
Shift plants to new locations near brighter windows for winter.
Wash dust off plants so leaves can make maximum use of available light.
Add artificial light. Fluorescent bulbs provide adequate light. They’re cheaper than traditional grow lights and produce less heat. Position bulbs 4 to 12 inches away from plants for effective results.
Temperature
Most of these plants and prefer temperatures between 65° F and 75° F during the day and about 10-15 degrees cooler at night. For tropical plants, temperatures below 50°F can cause problems. Hopefully, you had the chance to bring them in with the first cool spell a month ago.
Adjust thermostats for your comfort, but remember your plants need some consideration.
Avoid placing plants near cold drafts or heat sources.
Keep plants several inches away from exterior windows.
Humidity
Homes may offer only 5-10 percent relative humidity in winter. Houseplants like 40-50 percent. Signs of low humidity stress on plants include brown leaf tips and appearance of pests like spider mites.
Raise humidity around plants with a room humidifier.
Place plants on a pebble-lined tray filled with water. Keep the water level just below the pebbles. As the water evaporates, it raises humidity around plants.
Mist plants with room-temperature water. Avoid wetting walls or furniture.
A spider plant on a coffee table. Photo Credit: University of Florida/IFAS
Water
The most common problem plants suffer from in winter is overwatering. Most plants need soil to dry out almost completely before watering. How can you tell if plants need water?
Don’t just spot test the soil surface. Plants need water when the root zone is dry. Poke your finger into soil up to 2 inches. If the soil is dry, water.
Lift the pot. Soil is lighter when it’s dry. Learn how wet soil feels by lifting pots immediately after watering.
Exceptions to drying out between watering: Potted citrus and ferns require consistently moist soil. Always research plant moisture needs if you’re unsure.
When you do water, never allow plants to sit overnight in water that collects in the drainage saucer.
Fertilizer, Pruning and Repotting
Save these tasks until spring. Winter growth is usually leggy. Prune and fertilize to encourage bushy growth when the sunlight and temperatures increase. The right time to repot most tropical and houseplants is during periods of active growth – in spring and summer. The exception is potted woody plants that go completely dormant in winter. Transplant those prior to bud break in early spring.
Fall, winter and even early spring can be a rollercoaster ride of temperatures here in Northwest Florida. One week it dips to freezing for a short time and the next week it rises to spring-like temperatures. We need to hold on for this ride of up and down temperatures and not overreact too soon.
Following the sudden ride down to the lower temperatures, we may think winter is over. But we don’t see the next drop in temperatures that’s coming, as we are experiencing the ride upwards in temperatures.
On average, it’s not until we reach mid-March that we expect our last killing frost. A killing frost is heavy enough to kill tender plant growth. And, we can have light frosts well into the latter part of March and into early April. This is particularly true in the more northern portions of our Panhandle Counties.
The main point is to not get spring fever too early and encourage new plant growth by pruning or fertilizing too soon.
When landscape plants freeze, the first impulse may be to get out the pruning shears and cut away dead and dying leaves and branches. But this isn’t a good idea. Pruning can force new tender growth that is more likely to be injured by the next freeze. And, you can’t tell how much damage has been done until plants start new growth in spring. If you prune immediately after a freeze, you may cut away live wood that doesn’t have to be lost. Also, leaves and branches, which have been killed, can help protect the rest of a plant against further cold injury.
Some people want to “jump start” their lawns before our weather will allow our grasses to grow. Waiting allows for more efficient use of the lawn fertilizer. You will not injure your lawn by waiting but you can certainly injure your lawn by fertilizing too early.
So, have patience, allow your lawn to green up on its own and then fertilize, even if it’s not until April or May.
Finally, be a little philosophical. If you do lose one or two of your tender ornamentals, so what? Worse things could happen. And now you have a chance to add something new, perhaps some species native to our area that is not as subject to cold damage.
Even with this winter/spring rollercoaster ride, with thousands of plants to choose from and a generally mild climate, who can complain?
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.
