Q: I'm growing several annual flowers from seeds this year to create a cutting bed in my backyard. As a beginner, I'm uncertain about the right timing and method for transplanting seedlings from their indoor trays to larger pots and eventually outdoors. I've heard that transplanting too early can be detrimental. Can you provide some guidance?
A: Starting flowers from seeds is an excellent way to save money and it's quite manageable, but the initial steps are vital for thriving plants.
Make sure to use the ideal soil for seed starting to ensure a strong foundation. Wait until your seedlings reach a minimum height of one inch and have developed their second set of leaves before moving them, either individually or spaced 2 inches apart, into larger pots filled with multipurpose or potting compost.
A former professional gardener and allotment grower, Holly now writes about plants and outdoor living while tending to her extensive collection of houseplants.
Steps for Transplanting Seedlings into Larger Pots
Utilize a pencil, dibber, or plant label to carefully 'prick out' your seedlings from their initial trays. 'Handle them with care,' advises Hanna Bell from Gardeninghood.com. Instead of gripping the stems, support the seedlings by their leaves. Robert Silver from ProGardeningBlog offers this tip: 'Water the seedlings a few hours before transplanting. This will facilitate easier removal and reduce root damage.'
Use the same tool to create small holes in the new potting compost and gently place the seedlings. After transplanting, Hanna suggests lightly firming the soil around the roots and thoroughly watering the plants. Keep a close watch on your plants in their new environment, ensuring they get enough water and light to flourish.
'Once the seedlings have settled into their new pots, you can start applying a balanced fertilizer,' says Stacie Krljanovic, a Head Groundkeeper and advisor for Patio Productions. They will continue to grow here until it's time to move them outside.
A pencil is handy for carefully removing and replanting seedlings
Transplanting Seedlings Outdoors
'Soil temperature is the key factor when transplanting seedlings,' notes Kate Russell, from The Daily Garden. 'If the soil is too cold, seedlings will expend energy just to survive instead of thriving.'
Ensure that outdoor temperatures are consistently warm enough for the flowers you're growing and that frost risks have passed. Otherwise, your young plants may perish.
To reduce the risk of transplant shock, acclimate your seedlings first. Skipping this step is a common mistake. 'This involves gradually introducing them to outdoor conditions, such as wind, sunlight, and temperature variations over a week to ten days,' Stacie explains.
The process is simple – place the pots outside in a sheltered area during the day and bring them inside at night. Alternatively, you can leave them outside, covering them with cloches (available on Amazon), making sure to open them during the day to allow oxygen and excess heat to escape.
Be vigilant about slugs, as they are drawn to tender, green growth.
Once it's warm enough, you can begin to transition your seedlings outdoors
Q&A
When is it time to remove coverings from seedlings?
After sowing seeds indoors, you can either cover the trays with a clear plastic bag or use a tray with a lid, like these from Amazon, to enhance germination and maintain moisture. Once the seeds germinate and show green growth, remove the cover to allow air circulation and minimize disease risk.
As for seedlings that have recently been placed outdoors under cloches to harden off, you can typically uncover them after about a week, as long as frost threats have passed.
