You've carefully sown your seeds in pots or seed trays, and now tiny seedlings are emerging? Congratulations! But for them to grow into beautiful vegetables or flowers, an essential step awaits: transplanting.

Transplanting involves moving a young plant into a larger pot or directly into the ground to give it more space and nutrients.

But when and how should you do it? Which location to choose? What tools to use? Follow this tutorial to successfully transplant your seedlings in 5 easy steps and ensure they establish well.

Why transplant young seedlings?

Transplanting is essential to:

  • Give roots more space and prevent them from becoming tangled.
  • Strengthen the plant by stimulating its root system.
  • Promote vigorous growth with access to more nutrients.

What happens if you don't transplant?

  • Seedlings remain weak, fragile, and their growth slows down.
  • They grow poorly due to lack of nutrients.
  • Roots lack space and become tangled. 
  • They become more susceptible to diseases and moisture.

Essential tools for successful plant transplanting

For potting up

  • Larger pots, with drainage holes at the bottom.
  • Light, well-draining potting compost.
  • Clay pebbles (if transplanting into a final large pot).
  • A hand trowel or small shovel.
  • Water (preferably rainwater).
  • A spray bottle to gently moisten young seedlings.

For transplanting into the ground

  • A hand trowel or small shovel.
  • Rainwater for watering.
  • A spray bottle or watering can with a fine rose to water seedlings gently.

5 steps to successfully transplant your plants

Step 1: Know when it's time to transplant

Signs that it's time to transplant:

  • Seedlings have at least two true leaves (those that grow after the first germination leaves, called cotyledons).
  • Roots start emerging from drainage holes, indicating they need more space.
  • Growth slows down because the plant is cramped.

When to transplant?

  • For indoor transplanting : Can be done year-round, as soon as seedlings have several true leaves or seem cramped.
  • For outdoor transplanting : After the last frost, usually after mid-May in most regions (or when night temperatures exceed 10°C).
  • Vegetable garden : Tender vegetables (tomatoes, aubergines, peppers etc.) are typically transplanted from March-April under cover, and from mid-May outdoors.
seedlings ready for transplanting
Young tomato seedlings ready to be potted on (left) or planted directly in the ground (right).

Step 2: Harden off seedlings before outdoor transplanting

If your seedlings grew indoors or under cover, they're not accustomed to temperature variations, wind and sunlight. Sudden changes could weaken them.

How to harden off young plants before planting out?

  • Day -7: Take plants outside for a few hours daily, in a sheltered spot away from wind and direct sun.
  • Day -4: Gradually increase outdoor exposure (one extra hour daily) and begin sun exposure.
  • Day -2: Leave them outside all day but bring in at night.
  • Day 0: Plant them in the ground in late afternoon or on an overcast day to minimise stress.
young tomato seedlings placed outside to harden off
Before transplanting tomatoes to the garden, seedlings are placed outside for a few hours to harden off.

Step 3: Prepare seedlings before transplanting

  • Water seedlings a few hours before transplanting to ease removal.
  • Gently remove the plant from its pot or tray, holding it by the base (avoid pulling the stem).
  • Carefully loosen roots if they're tangled.
Gently remove seedlings from their trays
Carefully remove your young seedlings from their seed trays.

Step 4: Transplanting

In pots:

  1. If the plant will remain permanently potted: Place a drainage layer at the pot base: clay pebbles or gravel.
  2. Fill the pot with rich, well-draining potting compost, leaving enough space for the root ball.
  3. Place the root ball, leaving about 1cm gap between the pot rim and root ball top.
  4. Fill gaps with compost, then lightly firm around the plant to ensure good root contact.
  5. Place the pot in a bright spot, but avoid harsh sunlight for the first week while the plant adjusts.
transplanting young tomatoes into pots
Transplanting tomatoes: young seedlings, first sown in seed trays, are transplanted into biodegradable pots. In a few weeks, they'll be transplanted again into the ground.

In the ground:

  1. Using a trowel, dig a hole about twice as wide as the root ball. Weed the area and remove stones.
  2. Add some compost to the hole bottom to enrich soil.
  3. Lightly moisten the hole base before placing the plant.
  4. Place your root ball in the hole. The stem base should be level with the soil surface.
  5. Backfill with garden soil or compost and lightly firm.
transplanting lettuces into the ground
Transplanting lettuces in the garden

Step 5: Aftercare

  • Water thoroughly immediately after transplanting to moisten roots well.
  • In following days and weeks, water regularly but avoid overwatering to prevent root rot.
  • Use rainwater at room temperature to avoid temperature shock.
  • Some wilting is normal right after transplanting. Plants typically need a week to recover.
  • Fertiliser: After 2-3 weeks in the garden, add some compost or natural fertiliser (nettle tea, banana peel infusion).

? Tip: Add mulch (straw, dead leaves, wood chips) to reduce water evaporation and protect roots from temperature fluctuations.

Also watch Olivier and François demonstrate how to transplant lettuces in this video: