Repotting seedlings 101
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In late spring, I am a repotting queen! I use plug flats and cell packs to start my vegetable, flower, and herb seeds – they’re extremely efficient in terms of space – but, they don’t offer a lot of root room. After 6 to 8 weeks under the grow lights, many of the seedlings need to be repotted into larger containers to ensure continued healthy growth until it’s time to move them into the garden.
You’ll know your seedlings are ready to be repotted when their roots have filled their current containers and their foliage is crowding out the neighbours. Still not sure? Use a butter knife to pop a plant out of its pot and take a peek at the roots. If they’re well developed and encircling the soil ball, it’s time to repot.
Moving your seedlings to larger containers will help ensure a healthy root system and top-quality transplants for your garden. New containers should be about twice as large as the old ones.
This geranium seedling is ready for repotting. Note the well developed root system.
- Gather all your materials (pots, potting soil, tags, waterproof marker, butter knife) first so that repotting is quick and efficient.
- Water seedlings before starting. Moist soil will cling to the roots, protecting them from damage and drying out.
- No tugging! Don’t pull the baby plants from their cell flats or plug trays. Use a butter knife, narrow trowel, or even just a long nail to prick the seedlings from their containers.
- If there is more than one seedling in your container, gently tease them apart for repotting.
- Place them in the new pot, lightly tamping the soil.
- Have a stack of labels ready to go and give each pot a fresh tag. Alternatively, use a waterproof marker to write the name of the plant on the side of the pot.
- Water with a diluted liquid fertilizer to settle the roots in the new soil and encourage healthy growth.
Do you have any more repotting tips to add?
When your small seedlings outgrow their cell packs and plug flats, it's time for repotting: moving them into bigger containers. Learn how:
When And How To Transplant Seedlings Into The Garden
Raising plants from seeds can be a rewarding and exciting way to add new varieties to your garden. Many of the best and most unusual varieties of vegetables are simply not available in your local nursery and your only option is growing these plants from seeds. But in order to grow these unusual varieties, you must know something about planting seedlings.
How to Transplant Seedlings
One common question from people who are growing plants from seeds is, “How do I know when my seedlings are big enough to put out in my garden?” This is a good question to ask when learning how to start plants from seeds because planting seedlings out in the garden at the proper time is crucial to their development later on. If you put them out before they are ready, they may have a hard time surviving the elements. If you wait too long, your seedling may become pot bound in its original container.
When it comes to how to transplant seedlings, there is no hard and fast rule to how tall a plant should be before you put it out in the garden, due to the fact that different plants grow to different sizes. Also, the amount of light a seedling gets can influence how quickly a plant grows in height when you are raising plants from seeds. If there is not enough light, a plant can grow very tall very quickly, but this plant may or not be ready for planting out. The best way to judge if a plant is large enough to plant out in the garden is to look at the number of true leaves.
True Leaves on a Seedling
The general rule of thumb is that when a seedling has three to four true leaves, it’s large enough to plant out in the garden (after it has been hardened off).
When you plant a seed, the first leaves to emerge are the cotyledons. These leaves will look different from leaves that will grow later. The purpose of these leaves is to provide stored food to the seedling for a short period of time.
True leaves grow shortly after the cotyledons. The true leave emerge and start generating energy through photosynthesis that will help feed the plant for the rest of its life. Making sure that the plant has enough of these leaves to keep it sustained when planted out in your garden is important to its proper growth.
Just remember, it isn’t how tall but how many true leaves your plant has that will determine when you should be planting seedlings out. But even when your seeds are big enough to plant out, make sure you harden off your seedlings before planting them. When growing plants from seeds, you want them to be plenty prepared to grow into beautiful plants that will provide you with a bounty of delicious vegetables.
One common question from people growing plants from seeds is "how do I know when my seedlings are big enough to put out in my garden?" This is a good question to ask, and this article will help.