How & When To Transplant Seedlings From Seed Trays | Garden In Minutes® (2024)

FAQs

When to move seedlings out of trays? ›

As a general guide, after your seeds germinate they can grow in smaller (1.5″ cell trays) for about 2-3 weeks, in larger 2″ trays they can grow in them for about 3-4 weeks before needing to be transplanted. When it's time to transplant, wet your seedling tray soil & your garden's soil. This makes the soil stickier.

Remove the seedlings from their plug trays or pots then lay them out onto the surface, ready to plant. You can use a tape measure or ruler to get the spacing right, but with practice you'll be able to space them out by eye. Use a hand trowel, a dibber – or just your fingers – to make holes in the soil.

You'll know they're ready if their cotyledons are turning yellow, they've already grown 1 or 2 sets of true leaves, or their roots are growing through the drainage hole in their seed tray.

The general rule of thumb is that when a seedling has 3 – 4 true leaves, it is large enough to plant out in the garden (after it has been hardened off).

How big should seedlings be before transplanting? Seedlings should be at least 2-3 inches tall before transplanting and should have their two "true leaves."

It's important to avoid transplanting seedlings too early, as this can lead to shock and stunted growth. Similarly, waiting too long to transplant can result in the seedlings becoming root-bound, which can limit their growth and health.

Transplant on a calm overcast day.

Transplanting when bright sunshine is tempered by clouds reduces stress on your young plants. Dig holes that are larger than the pot your seedling is growing in, set your seedlings into the prepared soil and tamp them firmly into place. Water well.

These leaves look the same as those of the mature plant. So the first true leaves of a tomato plant look like mature tomato leaves. It's when the true leaves develop that photosynthesis really begins. I typically repot my seedlings when they've developed one to two sets of true leaves.

If possible, transplant on a warm, overcast day in the early morning.

Transplant shock happens when the roots of seedlings are disturbed in the transplanting process, causing stress to the seedling. Don't start these plants indoors. Instead, direct seed them in the garden. Be sure they are not in danger.

How long can seedlings stay in trays? ›

Typically, your seeds will stay in their seed tray for 4-6 weeks. After this period, you will either need to transplant the new seedlings into larger pots or transplant them outside. Check your seed instructions and pay attention to your frost dates before transplanting young plants outside.

The easiest way to harden transplants is to place them outside in a shaded, protected spot on warm days, bringing them in at night. Each day, increase the amount of sunlight the transplants receive. Don't put tender seedlings outdoors on windy days or when temperatures are below 45° F.

But you also can't leave your seedlings in their egg cartons for too long, waiting for the weather to heat up. Seedlings should be moved to the garden once the roots reach the bottom of the tray, but before they start to grow into a circle.

Typically, your seeds will stay in their seed tray for 4-6 weeks. After this period, you will either need to transplant the new seedlings into larger pots or transplant them outside. Check your seed instructions and pay attention to your frost dates before transplanting young plants outside.

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.

Seedlings should be separated and replanted into individual pots after they have received their first sets of true leaves. The cotyledon (or first set of leaves) forms once the seeds germinate. The cotyledon leaves help the plant to sprout by breaking open the seed coat.