Caring for Seedlings in My Greenhouse
The seeds we've been planting in my greenhouse are growing so nicely. My gardeners, Ryan and Wilmer, plant seeds into flats every week from now through March, when the weather is warm enough to garden outdoors. For now, they are being nurtured indoors where temperature, humidity and light can be properly controlled.
Starting from seed is not difficult, but it does require careful attention and patience. During these early stages of growth, they also need regular maintenance - thinning out those that are weak, pricking out those that are growing too big for their seed starting trays, and transplanting them into larger pots and flats.
Here are some photos of how we care for our young sprouts - enjoy.
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- These seedlings are in different stages of growth. They were planted from seed over the last few weeks. As they germinate and begin to mature, it’s important to check their development, so they continue to thrive.
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- Regardless of how perfect seeds may appear, germination is never guaranteed, so multiple seeds are always planted in each seed starting tray cell. This provides a better chance at least one in each cell will take root.
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- When the seedlings are a couple inches tall, and have reached their “true leaf” stage, which is when each seedling has sprouted a second set of leaves, it’s time for a process called selective thinning.
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- Selective thinning prevents overcrowding, so seedlings don’t have competition for soil nutrients or room to grow.
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- When thinning, carefully inspect the seedlings and determine the strongest ones. Look for fleshy leaves, upright stems, and center positioning in the space. The smaller, weaker, more spindly looking seedlings are removed, leaving only the stronger ones to mature.
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- Once selective thinning is complete, there should only be one seedling in each cell of the seed starting tray or container.
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- The stronger plants now have more room to grow before getting transplanted into larger pots or into the ground.
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- The span of windows helps to concentrate heat and sunshine to maximize plant growth.
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- As seedlings outgrow seed starting cell trays, they also need to be pricked out and transferred to individual pots, or larger trays.
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- A good quality organic mix designed for seedlings will be fast draining, and light. It will usually contain sphagnum moss and perlite or vermiculite. These mixes are formulated to encourage strong, healthy growth in new plants.
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- Fill the tray and using fingers or the end of a thick marker pen, make a hole in the center of each cell.
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- The tool on the left is great for seed starting – it’s from Johnny’s Selected Seeds. It’s called a widger. It has a convex stainless steel blade that delicately separates seedlings. On the right, 10-inch gardening tweezers that are also helpful for handling young plants. http://www.johnnyseeds.com/p-9765-widger.aspx
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- When it is time to move the seedling, carefully loosen the soil around the seedling with the widger. The widger also helps to avoid damage to the plant’s leaves, or roots.
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- Place the seedling in the hole and gently firm up the surrounding soil. Avoid handling the seedling by its tender stems, which bruise easily.
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- The growing seedling will remain in the new larger cell tray or pot until it is ready to plant into the ground.
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- Here is Wilmer transplanting a tray of seedlings. The purpose of transplanting is to provide enough room – overcrowding can stress the sprouts.
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- These look so much better in the new tray.
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- There are also many different kinds of pots and trays available in different sizes and materials. These are Fertil pots from Johnny’s that are made from 80-percent wood fiber and 20-percent peat moss. http://www.johnnyseeds.com/p-7606-fertil-pots-round-3-18-dia-x-3-18-h-90-pots.aspx
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- These pots are very easy to use and fill, especially when planting in an assembly line fashion.
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- Experiment with pots made from different materials to see which ones work best for what plants. And, always choose containers or trays that have proper drainage holes at the bottom.
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- These lupines were planted just a couple weeks ago – they are so green and healthy.
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- This is a heat mat specifically designed for seedlings. It warms the area and helps to improve root growth and increase germination rate.
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- Once seedlings are transferred, they’re given a good drink of water and returned to the greenhouse to continue growing.
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- Keep all seed starting trays moist and in a warm, sunny place. I dedicate an entire table in my greenhouse for seedings – it is so nice to be able to grow vegetables and flowers during these colder months in preparation for spring when they are moved outdoors.
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