Repotting guide

When & how to repot Webb's Wonderful Lettuce (Lactuca sativa)

Also called Crisphead lettuce, Iceberg-type lettuce, Webb's Wonderful.

More about webb's wonderful lettuce

About Webb's Wonderful Lettuce

Lactuca sativa · also called Crisphead lettuce, Iceberg-type lettuce · edible

Webb's Wonderful is a classic British crisphead lettuce prized for its large, tightly-packed hearts and crisp texture. Sow successionally from March to August for harvests across the season. Fast-maturing at around 70 days, it thrives in cool weather. Fully edible and pet-safe — no toxicity concerns for dogs, cats, or humans.

Mature size: 25-30 cm spread; hearts 15-20 cm in diameter

How to tell webb's wonderful lettuce needs repotting

Repotting on a calendar is less reliable than reading the plant. For webb's wonderful lettuce, watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot webb's wonderful lettuce on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot webb's wonderful lettuce

Pot on seedlings as they grow; not a perennial repot. Webb's Wonderful Lettuceis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Low-growing annual rosette forming a tight heart.

What size pot to step webb's wonderful lettuce up to

Pot webb's wonderful lettuce on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot webb's wonderful lettuce

Pot webb's wonderful lettuce on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting webb's wonderful lettuce

Pot on before it is root-bound. Check webb's wonderful lettuce regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh fertile, moisture-retentive but well-drained loam at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water webb's wonderful lettuce in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for webb's wonderful lettuce

Webb's Wonderful Lettuce wants fertile, moisture-retentive but well-drained loam. Enrich with well-rotted compost before planting. pH 6.0–7.0 is ideal. Avoid compacted or waterlogged ground, which encourages root rot. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting webb's wonderful lettuce — frequently asked questions

How often should you repot webb's wonderful lettuce?

Pot on seedlings as they grow; not a perennial repot for webb's wonderful lettuce. Webb's Wonderful Lettuce is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into fertile, moisture-retentive but well-drained loam so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does webb's wonderful lettuce need?

When is the best time of year to repot webb's wonderful lettuce?

Can you put webb's wonderful lettuce straight into a much bigger pot?

No. Even a fast-growing webb's wonderful lettuce should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise webb's wonderful lettuce after repotting?

Not immediately. Wait about 1 week after repotting webb's wonderful lettuce. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.