Every spring the same display appears: seed racks, trays of plugs, and shelves of living herbs lined up next to the bagged salad. All three promise a kitchen windowsill full of leaves. They get there by very different routes, at very different costs, and with very different amounts of fiddling in between.
The cheapest option at the till is rarely the cheapest by the time you have a bowl of pesto in front of you. So here is an honest comparison of the three routes: what you pay up front, what you get back, and what the plants will ask of you week after week.
Seeds: pennies per plant, weeks of waiting
A packet of basil or coriander seed holds far more than you will sow in a single tray, and a single packet can keep you in herbs for a whole season. Kept cool and dry in a tin, most herb seed stays viable for two or three years. Per plant, nothing else comes close on cost.
What you pay in return is time and attention. Basil germinates in about a week at 18–21°C. Parsley can sulk for three weeks or more. Chives and rosemary are slower still and uneven, which is why many gardeners buy those as plants and save seed-sowing for the fast, cheap annuals.
A few practical points make the difference between success and a tray of pale, leggy seedlings:
- Sow thinly in peat-free multipurpose compost and cover with a fine layer, roughly the depth of the seed.
- Put the tray somewhere bright and warm. A kitchen windowsill in March is often too cold and too dark; a warm, light room is better.
- Thin the seedlings once they have two true leaves. Crowded seedlings compete, stretch and topple.
- Sow a small pinch every three or four weeks rather than one big tray, so you have a continuous supply instead of a glut followed by nothing.
Plug plants: a head start for modest money
Plugs are small rooted plants, usually sold in trays of six to twelve by mail order or from a garden centre bench. You skip germination entirely, which removes the riskiest part of growing from seed, and you can choose named varieties — a bush basil that stays compact on a sill, or a slow-bolting coriander that lasts longer before running to flower.
Pot them on into 9cm pots of multipurpose compost as soon as they arrive, water them in and grow them on somewhere bright. If they are destined for a balcony or a patio pot rather than the kitchen, harden them off over a week or so: stand them outside for a few hours each day, extending the time gradually, before leaving them out overnight.
You pay more per plant than you would from seed, but less than you would for the same herb in a supermarket pot, and you start several weeks ahead.
Supermarket pots: quick, but read the label
Those living herb pots are sold as a cut crop, not as garden plants. Basil is typically sown thickly — a dozen or more seedlings crammed into one small pot — which is why it collapses within a fortnight. The leaves yellow, the compost stays wet, and grey mould moves in.
The fix is to divide and repot them, and it takes about ten minutes:
- Water the pot an hour beforehand so the rootball holds together.
- Tip the whole thing out into your hand and gently tease the seedlings apart.
- Pot them in threes into 9cm pots of peat-free multipurpose compost, firming gently.
- Water, then keep them out of strong midday sun for two or three days while they settle.
Divided like this, a supermarket basil will crop for months and give you several pots for the price of one. Parsley and coriander behave similarly, though both will eventually bolt and need replacing. Supermarket mint is worth keeping, but give it its own pot — it spreads. Rosemary and thyme sold this way are usually forced into soft, fast growth and struggle indoors; put them outside in a gritty compost and they will do far better.
Comparing cost, yield and upkeep
- Up front: seed is cheapest by a wide margin. Plugs sit in the middle. Supermarket pots cost the most per plant, though dividing them narrows the gap.
- Time to first harvest: supermarket pots win, at a few days. Plugs take two to four weeks. Seed takes four to eight weeks depending on the herb.
- Yield: a seed packet, sown in succession, gives the most leaves over a season. Divided supermarket basil yields surprisingly well. Plugs are reliable and generous but limited to the plants you bought.
- Weekly upkeep: much the same for all three — watering, pinching out flower buds and picking regularly.
- Risk: seed is the riskiest start; plugs the safest; supermarket pots fail fastest if left as bought.
The maintenance nobody mentions
Whichever route you take, the plants end up with the same three needs: light, water and picking.
Light is the one that decides everything indoors. Herbs want a bright sill — ideally several hours of direct sun — and in a British winter even a good south-facing window will not be enough for basil or coriander. Expect them to slow down or give up between November and February, and plan to resow in spring rather than nurse a tired plant through the dark months. Hardy perennials such as mint, chives, thyme, oregano and rosemary are happier outside in pots all year.
Watering is where most kitchen herbs are lost. Little pots dry out quickly in sun, but basil in particular hates sitting wet. Check the compost with a finger before watering, and never leave a pot standing in a saucer of water. Feed lightly every couple of weeks during the growing season, and pinch out the growing tips regularly: cutting above a pair of leaves encourages bushy growth rather than one sad, leggy stem. Keep an eye out for greenfly and whitefly, and deal with them early with a squirt of water or a soap-based spray.
Which route suits you?
If you enjoy the process and want the widest choice, seed is the best value. If you want results with minimum fuss, buy plugs. If you want leaves tonight and don’t mind repotting, divide a supermarket pot. Many kitchens end up using all three: seed for basil and coriander, a bought plant or two for mint and rosemary, and a supermarket pot in reserve for the week the coriander bolts.
Start with one pot
Pick a single herb you actually cook with, choose the route that matches your patience and your light, and give it a proper pot with drainage. Basil in a sunny kitchen, mint outside the back door, chives in a pot by the sink — that is a herb garden. Add another when the first is thriving, and by midsummer you will be cutting more than you can use.
Photo: 0815Sch / Pixabay
