Keeping Supermarket Herbs Alive

That pot of supermarket basil or parsley on your kitchen counter was never built to last. It is grown for the shelf, not for your windowsill — a quick splash of green that's meant to be picked clean and binned within a fortnight. The good news is that you can rescue it. With ten minutes and a bit of fresh compost, a £1 pot can carry on growing for months. Here's how to do it, herb by herb.

Why supermarket herb pots collapse

Supermarket pots fail for one simple reason: they are dramatically overcrowded. Where you might sow a dozen seeds, a grower has crammed in fifty or more, then forced them on fast under heat and bright light to get a full, leafy pot onto the shelf as quickly as possible.

All those seedlings are sharing a thimble of compost. Their roots knot together into a solid, pot-bound plug with no room left to grow and no spare nutrients to draw on. The compost is already exhausted by the time you buy it. So within a week or two the plants run out of food, water and air at the roots all at once — and the whole pot wilts and browns, no matter how carefully you water.

Heat-loving herbs like basil suffer fastest, because the warm shop and your warm kitchen push them to grow hard while the roots are already strangled. Leafy herbs such as parsley hang on a little longer but go the same way. None of it is your fault — the pot was simply designed to be used up, not kept.

The rescue: split and re-pot

This is the heart of the whole job, and it takes about ten minutes. You'll need a few small pots (9cm pots are ideal, or anything with a drainage hole), some fresh multipurpose compost, and a watering can.

1. Water the pot first. An hour before you start, give it a good drink. Damp roots slide apart far more kindly than dry, crumbly ones.
2. Tip it out. Spread your fingers over the top of the compost, turn the pot upside down and squeeze gently until the whole plug drops into your hand. Don't pull on the stems.
3. Divide into clumps. Gently tease the root mass into three or four smaller clumps with your fingers. You will tear some roots — that's fine and unavoidable. Aim for clumps roughly the size of a golf ball, each with a fair share of stems.
4. Pot each clump on. Sit each clump in its own pot, fill around it with fresh compost so the roots are covered to the same depth as before, and firm in lightly.
5. Water and settle. Water each pot until it runs from the base, then set them somewhere bright but out of harsh midday sun for a day or two while they find their feet.

Giving each clump its own pot of fresh compost solves every problem the supermarket created at once: room to root, food to draw on, and air around the roots. Expect a day or two of sulking — a little wilting is normal after the upheaval — followed by fresh, vigorous growth.

Aftercare for each herb

The split is the same for every herb. What differs is how you treat each one afterwards.

Basil wants warmth above all. Keep your re-potted clumps on the warmest, brightest windowsill you have — a south- or west-facing kitchen sill is perfect — and never let them sit in cold, soggy compost overnight. Water in the morning, let the surface dry slightly between drinks, and pinch out the growing tips regularly to keep the plants bushy. Our basil guide covers the pinching trick in full, and it's the single best habit for a long-lived plant.

Parsley asks mainly for patience. After being split it can sit and sulk for a couple of weeks before it visibly picks up — this is normal and not a sign it has died. Keep it cooler than basil, water steadily, and resist the urge to fuss. Once it settles it is tough and long-lasting, and a re-potted clump will keep cropping for months. The parsley guide has more on keeping it productive.

Coriander is the fussiest, because it hates root disturbance and bolts (runs to flower) at the slightest stress. If you must split a supermarket pot, do it as gently as you can and expect some of it to run up to seed anyway — that's coriander's nature, not your failing. Honestly, the most reliable approach is to use the bought pot up quickly and sow your own thinly instead. The coriander guide explains how to grow it from seed, and you can read more on stopping it running to flower in our note on coriander bolting.

Hardening off before they go outside

Once your rescued herbs are growing strongly and the weather is mild, you may want to move the tougher ones — parsley, mint, chives — out to a doorstep or windowbox. Don't simply carry them straight outside.

A pot raised in a warm shop and a warm kitchen has soft, pampered growth that the wind and cooler nights will scorch in a day. Instead, harden them off: stand the pots outside in a sheltered, partly shaded spot for a few hours each day, bringing them back in at night, and gradually build up over a week or so until they're out around the clock. Wait until the risk of frost has properly passed — in most of the UK that means late May — before leaving any tender herb out overnight.

Basil and coriander are best kept indoors in our climate. Basil in particular rarely thrives outside in a British summer; it is far happier on a bright sill, as the basil guide explains.

When to use it up and sow your own instead

Rescuing a pot is satisfying and well worth doing, but be honest about when it's the right call. A supermarket pot costs around £1 and, even split, gives you a few months at best. A packet of seed costs about the same, holds dozens of sowings, and — sown thinly, a few seeds at a time — keeps you in fresh herbs for far longer and far more cheaply.

So treat the rescue as a stopgap, not a strategy. Split and re-pot the herbs you've already bought, enjoy them while they last, and use that breathing space to start your own from seed. Basil, parsley, coriander and chives are all genuinely easy crops for beginners, and a small container of compost on a sunny sill is all most of them need. It is also a lovely first project to do with children.

When you're ready to take that step, a few packets of fresh seed go a very long way:

The full method for a windowsill pot that keeps going for months — sowing thinly, the pinching trick, light and watering — is in our basil guide. Master that and you'll never need to rescue a supermarket pot again.