Regrowing garlic, leeks and lettuce: what really grows

A leek base or a lettuce stump can grow new leaves, but not necessarily an entire vegetable. Garlic, on the other hand, needs to be planted in soil to form a new bulb.

A lettuce stump or leek base can produce new leaves in a little water. But seeing green growth does not mean the whole vegetable is growing back: regrowth, taking a cutting and producing a crop are three different things.

Leaves regrow, but not necessarily a new vegetable

A plant can start growing again from living tissue and reserves stored in the part that has been kept. Placed in water, a leek or onion base can therefore put out new shoots. The result is visible and sometimes useful in cooking, but it does not necessarily amount to recreating a whole leek or onion.

This is the key distinction when assessing videos of ‘regrowing vegetables’. A handful of leaves is not a new bulb, a new root or a whole lettuce. A feature broadcast by Ici describes this regrowth as an interesting experiment for salvaging foliage, while warning that it is no substitute for a vegetable garden.

To try it, keep a base that is still firm, with its roots if it has any, and place it in a clean container with a little water. Avoid immersing it completely. Change the water regularly and watch what grows: the realistic goal is to get a few leaves, not to guarantee a full harvest. If the base deteriorates, the experiment is over.

Leeks and lettuce: limited regrowth

With a leek, the rooted part left after cutting can produce new foliage. These shoots can be used to flavour a dish. They should not be confused with a new leek, which would require different growing conditions to form.

The same principle applies to a lettuce stump. It can develop a few leaves, but images of a whole lettuce recreated in a glass of water give a misleading impression of the result. The growth observed depends on the part kept and its condition; it is not a reliable way to replace lettuce bought or harvested in the garden.

Ici’s feature therefore recommends treating these experiments as educational rather than as a promise of production. A Planet Organic guide suggests that transplanting into soil after new roots appear may allow some leafy vegetables to continue growing. However, the information is not enough to guarantee that a stump will produce a whole head: it is better to present this as something to try, not as a certain outcome.

Garlic: a clove, but with soil

Garlic illustrates a different situation. A clove can produce a new bulb, but sprouting it in a glass of water is not enough to get a comparable harvest. According to Ici’s feature, the cloves — the small units that make up the bulb — must be separated and planted in the ground, generally in autumn or late winter, depending on the variety.

A clove that puts out a shoot on a windowsill has therefore not gone through the same cycle as one grown to form a bulb. Foliage may appear without the conditions needed for a new bulb being in place. To try growing garlic properly, the clove must be planted in soil and the timing appropriate to the variety taken into account; simply putting it in water is no shortcut to a head of garlic.

From regrowth to harvest: what changes

A cutting is a piece of a plant that is encouraged to take root so that it can continue growing. A vegetable base regrowing in water can be similar, but it does not automatically produce a plant capable of yielding a full harvest. For some crops, soil becomes necessary; for others, the part kept does not contain what is needed to recreate the vegetable that was eaten.

In practice, these experiments can be interesting for observing growth and making use of a few shoots. They promise neither food self-sufficiency nor a significant reduction in shopping. If the aim is to harvest a whole vegetable, you need to choose a method suited to the plant and accept that visible regrowth does not guarantee what happens next.