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Repotting guide

When & how to repot Corn Salad (Valerianella locusta)

Also called Corn Salad, Lamb's Lettuce, Mâche, Field Salad.

More about corn salad

About Corn Salad

Valerianella locusta · also called Corn Salad, Lamb's Lettuce · edible

Corn salad (mâche) is a cool-season salad green with mild, nutty-flavoured rosette leaves harvested baby or mature. Extremely cold-hardy, it thrives in autumn, winter, and early spring when most salad crops fail. Quick to mature at 45–60 days, it self-seeds freely and is a staple of year-round salad growing in temperate UK and US climates.

Mature size: 10–20 cm tall rosette; 15–25 cm spread

How to tell corn salad needs repotting

Repotting on a calendar is less reliable than reading the plant. For corn salad, watch for these signs:

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 corn salad

Pot on seedlings as they grow; not a perennial repot. Corn Saladis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Low-growing rosette-forming annual or overwintering biennial. Leaves spatula-shaped, mid-green. Tiny pale blue flowers when bolted in spring..

What size pot to step corn salad up to

Pot corn salad 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 corn salad

Pot corn salad 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 corn salad

  1. Pot on before it is root-bound. Check corn salad regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
  2. 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.
  3. 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.
  4. Pot into rich mix. Set it into fresh moisture-retentive loam or compost-enriched soil, ph 6.0–7.0 at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
  5. Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water corn salad 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 corn salad

Corn Salad wants moisture-retentive loam or compost-enriched soil, ph 6.0–7.0. Adaptable but performs best in reasonably fertile, moisture-retentive soil. Incorporate well-rotted compost before sowing. Very tolerant of heavier soils unlike most salad crops, making it suitable for UK garden plots where lettuce struggles in winter. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting corn salad — frequently asked questions

How often should you repot corn salad?

Pot on seedlings as they grow; not a perennial repot for corn salad. Corn Salad is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into moisture-retentive loam or compost-enriched soil, ph 6.0–7.0 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 corn salad need?

Pot corn salad 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. Use our pot size calculator to size it from the plant's current pot and root spread.

When is the best time of year to repot corn salad?

Pot corn salad 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.

Can you put corn salad straight into a much bigger pot?

No. Even a fast-growing corn salad 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 corn salad after repotting?

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

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