Michigan Greenhouse Seedling Time?

Starting seeds indoors in Michigan is generally advised to do so 6-8 weeks before the last expected frost date, such as around mid-May in lower Michigan. This is because the state has a short growing season and cold winters, making greenhouse gardening a natural choice.

Warm-season crops, which are susceptible to frost, should not be planted until after the danger of frost. Many warm-season crops are best planted as seedlings. In Michigan, planting seeds directly in the garden is not possible in April unless you are planting under plastic in a high tunnel or green house. Soil must reach 70 degrees for seeds to germinate.

In January, seeds of perennial and biennial flowers, herbs, and vegetables (artichokes) should be started indoors. In mid-February, onions, leeks, and other vegetables should be started indoors. For seeds that take a long time to mature, they can be started indoors in February.

Some seeds that take a long time to mature or can be planted outside early can be started indoors in late April/early May. Transplanting onions, leeks, potatoes, and other plants can be done in the garden.

Starting seeds indoors is crucial to avoid a killing frost when planted out or seedlings becoming too cold. Start seeds indoors about 6 weeks before the last frost to avoid potential issues.

Do I need to harden off seedlings before putting in greenhouse?

Hardening off is a crucial process for mature plants grown inside a greenhouse, as it involves slowly acclimating them to a new environment to prevent shock, damage, or even death. When plants are raised indoors in early spring and moved outside for planting, they must adapt to direct sun, cooler temperatures, lower humidity, increased air movement, winds, and pest and disease pressures, which are unpredictable and out of control.

Proper hardening off results in thicker cell walls and leaf structures, increased energy for root development, and reduced excess water, making the plant stronger, more rigid, and less susceptible to freeze damage. As plants grow slower, they create a firmer, less floppy plant that can handle the stresses of the outdoors. If not hardened off, wind, sun, or cold can lead to significant wilting, browning leaf edges, or even death.

Hardening off is a time-intensive process, ideally done over two weeks, but it is generally more sensitive than bringing home well-rooted, mature plants from a greenhouse and acclimating them to their new environment. It is essential to follow guidelines for hardening plants off when preparing for outdoor planting and to simplify the process when moving crops outside for sale or at home.

Why are my seeds not germinating in my greenhouse?

High soil temperatures for germination can be a problem for seeds, as they do not thrive in temperatures over 80° F. To avoid this, adjust the temperature control on your heat mat or invest in a soil thermometer for direct planting. Some crops like spinach and lettuce thrive at cooler temperatures, while tomatoes, peppers, and eggplant thrive in warmer temperatures.

Incorrect seeding depth is another issue, as seeds should not be buried too deeply, as they won’t have the energy needed to push through the soil and reach the surface. If you are seeding by hand, be cautious and adjust the seeding depth accordingly. If using a seeding tool, follow the instructions and adjust accordingly.

Inadequate moisture is another issue, especially for pelleted seeds, which are covered in a fine coating of talc or clay powder mixed with a sticking agent. If the mixture dries out during the germination process, it becomes hard and makes it nearly impossible for the seed inside to germinate and emerge. Pre-moistening your seed starting mix or soil prior to seeding can greatly improve germination rates. To maintain adequate soil moisture levels after sowing seeds, use a plastic dome to cover trays or pots, water with a spray bottle or misting head on your hose, and remove the dome as needed.

When can I start seeds in a greenhouse in Michigan?

March is an ideal time to start seedlings indoors, 6-10 weeks before the last frost date in Michigan, which is typically May 15th. Growing plants from seeds is cost-effective, fun, and a great way to start spring. It’s also a great way to get children involved in gardening and watch tiny seedlings blossom into healthy mature plants. Seeds are best sown directly in the garden when the soil has warmed to approximately 70 degrees, usually in May or June in Michigan. This activity is also a great way to grow specific varieties.

Will plants be ok in an unheated greenhouse?

Winter greenhouse growing presents challenges, but it’s crucial to adapt gardening practices to ensure success. Adequate lighting is essential, especially during reduced daylight. Regular rotation of plants and benches ensures even distribution of sunlight. Full-spectrum LED grow lights can supplement natural light on overcast days or during limited sunlight periods. Adjustable lights can be used to tailor intensity and photoperiods to different crops’ needs. Time artificial lighting to extend the day length rather than interrupting the night. By understanding these challenges, you can ensure a successful winter greenhouse growing experience.

How early can you start seeds in a greenhouse?

Greenhouses offer a controlled environment for seed propagation and young seedling growth, allowing for seed starting anytime. For transplanting plants outdoors in the spring, start seeds six to eight weeks before the last expected frost date. For optimal success, germinate seeds in temperatures between 70-80 degrees F., with night temperatures not dropping below 50-55 degrees F. The greenhouse temperature should be carefully monitored, as it can get cooler at night. Seedling heat mats can provide consistent warm soil temperatures, and greenhouses with fans or windows can vent overheated areas.

Can a greenhouse get too hot for seeds?

To maintain a healthy backyard greenhouse, it’s crucial to maintain a temperature between 80-85°F (26-29°C) during spring and summer months. If the temperature exceeds 90°F, it’s a sign of potential health issues. To keep the greenhouse cool, use a thermometer or walk inside to gauge the temperature. Consistent watering is the most important tip, as it helps plants thrive and reduces greenhouse temperatures. These tips can be more effective when implemented together, making the greenhouse a more comfortable and healthy space for your plants.

Do seeds grow faster in a greenhouse?

Plants require warmth, humidity, and light for growth. A greenhouse stabilizes the growing environment by buffering ambient temperature and protecting plants from extreme cold, extending the growing season and enabling early sowing and harvest. By sowing successionally, greenhouse growers can reap early harvests, especially by nurturing late-sown seedlings.

The greenhouse also protects plants from pests and diseases, allowing them to become an oasis free from flying pests like adult aphids and egg-laying butterflies. By implementing biological controls and limiting access to the greenhouse, pests can be minimized without toxic chemicals. This allows for organic produce for the family.

Tomatoes can be grown in a greenhouse environment to minimize plant diseases like blight. Fungal spores are less likely to reach plants, and the growing conditions inside the greenhouse are less conducive for fungi to infect them. By choosing blight-resistant varieties, tomato blight can be virtually eradicated, providing a significant advantage over growing outside.

What happens if you start seeds indoors too early?

Grow-light gardeners can avoid issues with lack of light as long as the light bulbs are placed 3 inches above the plants. This will help produce sturdy, well-branched seedlings. However, starting seeds too soon can result in bigger plants, which need to be potted up into larger containers, which can cost more money for potting soil, organic fertilizer, and pots. Additionally, sizable seedlings require more frequent irrigation.

Big plants can bolt, leading to flowers and fruits being produced while still inside the house. This is particularly true for tomatoes, which grow best when transplanted outdoors six to nine weeks from sowing seed. Bolting can also negatively affect other seedlings, such as broccoli, lettuce, cabbage, cauliflower, squash, cucumbers, and pumpkins, reducing or eliminating harvest.

Holding seedlings indoors too long can also lead to pest and disease problems that may not have been present if transplanted outdoors sooner. Therefore, it is essential to start seeds indoors when they are well-lit and well-branched to avoid potential issues.

How cold is too cold for seedlings in a greenhouse?

To slow down crop growth in a market, reducing the temperature is the best way to do so. Most crops can tolerate an average temperature of 50° F, with cold-tolerant crops handling temperatures of 35 to 40° F. Cold-sensitive crops, like basil, should not be held below 55° F. When temperatures are significantly reduced, plants need less water but still need some water. Low temperatures don’t need as much light, but crop quality can be reduced if given too much shade.

Increasing humidity decreases the amount of moisture that air holds, making it more difficult for plants to dry out and leaves stay wet longer. This can also inhibit rooting, which can be problematic during propagation and transplanting. Therefore, humidity and moisture management become more important when greenhouse temperature is reduced.

Freezing or chilling injury occurs when plants are exposed to temperatures below freezing, which is not suitable for many cold-sensitive plants, including those native to tropical areas. Chilling injury can occur at temperatures above freezing and as high as 54° F. The potential of freezing and chilling damage increases with the duration of low temperature exposure and the magnitude of the temperature decrease.

When can you plant seeds in unheated greenhouse?

Seedlings can germinate in an unheated greenhouse during colder months, such as late winter to early spring. They can be placed in their seed starting trays or pots when they are still tiny, and can be transplanted when they have just two sets of leaves upwards, usually 2-4 weeks old. The ideal temperature for starting seedlings in an unheated greenhouse is around 18 degrees Celsius or 65 Fahrenheit, with a nighttime temperature of around 10 degrees Celsius or 50 Fahrenheit. Too much temperature drop can hinder seedling development, and anything over 24 degrees Celsius or 75 Fahrenheit is considered too warm.

Can you put seeds straight into a greenhouse?

A greenhouse is a controlled environment that helps control the temperature and humidity needed for seeds and seedlings to grow. To start plants in the spring, start seeds in the greenhouse six to eight weeks before the expected frost date. Ensure that seeds germinate in a temperature between 70-80 F. (21-27 C.) and monitor the greenhouse’s temperature closely. A seedling heat mat can help maintain consistent soil temperatures, and if the greenhouse gets very hot, open windows or install fans to maintain suitable temperatures.

Seeds can be started inside individual plug trays or open flat seed trays, depending on their requirements. Some seeds require scarification, stratification, or overnight soaking before planting. For open flat trays, consider spacing seeds in carefully spaced rows for easier thinning, fertilizing, and watering processes, as well as for treating seedling diseases.