Growing Herbs and Salad Leaves on a Windowsill or Balcony

A small bunch of fresh herbs from the supermarket often costs as much as a bag of potatoes, and half of it tends to wilt before it is used. Growing a few herbs and salad leaves at home fixes both problems. A pot of parsley on a windowsill gives you a few sprigs whenever you need them, for months, and a tray of salad leaves can be cut again and again.

You do not need a garden. A sunny windowsill, a balcony or even a doorstep is enough to start. This guide explains which plants are easiest, what you need, and how to keep them productive.

Why it saves money

The savings from home-grown herbs come mostly from avoiding waste and avoiding repeated small purchases:

• You pick exactly what a recipe needs, so nothing wilts in the fridge.
• One plant replaces many shop-bought packets over a season.
• Seeds are inexpensive, and a single packet can last more than one year if stored somewhere cool and dry.
• Supermarket "living herb" pots, if repotted and cared for properly, can keep producing for weeks or months instead of dying within days.

Home growing will not replace your whole vegetable shop, but for herbs and salad leaves — some of the most expensive produce per gram — the difference is real.

The easiest plants to start with

Herbs

• Chives. Very easy, tolerant of a range of conditions and come back year after year. Snip the leaves for eggs, potatoes and salads.
• Parsley. Flat-leaf and curly both grow well in pots and produce for a long time if you pick the outer stems.
• Mint. Extremely vigorous — so vigorous that it is best kept in its own pot so it does not take over. Excellent for tea, salads and sauces.
• Basil. Loves warmth and sunshine; a good choice for a bright, warm windowsill. Pinch off the tops regularly to keep it bushy.
• Thyme, rosemary and oregano. Mediterranean herbs that like sun and prefer their soil on the dry side. Slow-growing but long-lived.
• Coriander (cilantro). Tastes wonderful but tends to run to seed quickly in heat; sow small amounts every few weeks for a steady supply.

Salad leaves

• Cut-and-come-again lettuce mixes. Sown thickly in a tray or window box, they can be harvested by cutting leaves a couple of centimetres above the soil, then left to regrow.
• Rocket (arugula). Fast-growing with a peppery flavour.
• Spinach and chard. Young leaves for salads, larger leaves for cooking.
• Pea shoots. Dried peas sown thickly in a tray produce tender shoots within a few weeks.
• Microgreens. Seedlings of plants like radish, mustard or cress, harvested very young — some are ready in about a week.

What you need

A home herb garden needs very little equipment:

• Containers with drainage holes. Any pot will do, including reused yoghurt pots or food tubs with holes punched in the base. Stand them on saucers or trays to catch water.
• Compost. A general-purpose or seed compost from a garden centre. Garden soil is too heavy for pots and may carry pests.
• Seeds or young plants. Seeds are cheapest; young plants give faster results.
• Light. The single most important factor. Most herbs need several hours of direct light a day.
• A watering can or jug.

Finding the right spot

Light makes or breaks indoor herbs. In general:

• The sunniest windowsill you have is the place for basil, rosemary, thyme and oregano.
• Bright but less sunny spots suit parsley, chives, mint and salad leaves, which tolerate some shade.
• Turn pots regularly so plants do not lean towards the window and grow lopsided.
• Keep plants away from radiators and draughty gaps, which dry them out or chill them.

In darker homes or during short winter days, growth slows. A small LED grow light can help, though it adds a little electricity cost, so weigh this up against the value of the herbs you grow.

Sowing seeds step by step

1. Fill the container with compost to about a centimetre below the rim and gently firm it.
2. Water the compost before sowing so the seeds do not wash away.
3. Sow thinly. Scatter small seeds across the surface or in shallow lines. Larger seeds, such as peas, can be pressed in individually.
4. Cover lightly with a fine layer of compost — roughly the depth of the seed itself. Some very fine seeds need only to be pressed onto the surface.
5. Keep moist but not soggy. A clear plastic bag or lid over the pot keeps humidity in until seedlings appear; remove it once they do.
6. Thin out crowded seedlings so the remaining plants have room to grow. The thinnings of salad and herbs can be eaten.

The seed packet will give specific depths and spacing for each plant.

Rescuing supermarket herb pots

Supermarket pots of basil, parsley and coriander usually contain many seedlings crammed together, which is why they collapse after a few days. You can turn one pot into several healthy plants:

1. Gently remove the root ball from the pot.
2. Divide it carefully into three or four clumps.
3. Plant each clump in its own pot of fresh compost.
4. Water well and keep the pots in a bright place.

Given space, the divided plants often keep growing for weeks or months.

Watering without drowning

More indoor herbs die from too much water than too little.

• Check before watering. Push a finger into the compost; water only when the top centimetre feels dry.
• Water thoroughly, then drain. Let excess water run out of the drainage holes and empty saucers after half an hour so roots do not sit in water.
• Mediterranean herbs prefer drier conditions. Rosemary, thyme and oregano like to dry out a little between waterings.
• Leafy herbs and salads drink more, especially in warm weather and on sunny balconies.

Harvesting for a long supply

How you pick determines how long a plant produces.

• Basil: pinch out the top pair of leaves just above a pair of side shoots. The plant branches and becomes bushier. Remove flower buds as they appear.
• Parsley and coriander: cut the outer stems close to the base, leaving the centre to keep growing.
• Chives: cut a few stems at a time a couple of centimetres above the soil.
• Mint: cut stems back regularly; it regrows quickly.
• Salad leaves: cut leaves a couple of centimetres above the soil, or pick the outer leaves of individual plants.
• Never strip a plant bare. Leave at least two-thirds of the foliage so it can recover.

Feeding and repotting

Compost contains nutrients that last a few weeks. After that, a plant that is harvested often benefits from occasional feeding with a general liquid plant food, diluted according to the instructions. Perennial herbs such as rosemary, thyme, mint and chives may need moving to a larger pot once their roots fill the container.

Balcony growing

A balcony opens up more possibilities: larger troughs of salad, a pot of cherry tomatoes, climbing beans or a strawberry planter. A few considerations:

• Wind dries pots quickly and can damage tall plants; group containers together for shelter.
• Weight matters on balconies; check any building rules and avoid overloading.
• Watering must not drip onto neighbours below — use saucers and water carefully.
• Sun direction determines what will thrive: south- and west-facing balconies (in the northern hemisphere) are warmer and brighter.

Keeping pests in check

Indoor herbs occasionally attract aphids, whitefly or fungus gnats.

• Inspect leaves regularly, especially undersides.
• Rinse small infestations off with water or wipe leaves with a damp cloth.
• Avoid overwatering, which encourages fungus gnats.
• Remove badly affected leaves promptly.

Because you will be eating these plants, avoid chemical pesticides unless the product is explicitly approved for edible crops and you follow the label instructions precisely.

Preserving a glut

When plants produce more than you can use:

• Freeze chopped herbs in ice-cube trays with a little water or oil, ready to drop into sauces and soups.
• Dry woody herbs like rosemary, thyme and oregano by hanging small bunches in a warm, airy spot away from direct sun.
• Make a simple herb sauce or pesto and freeze it in portions.

What it costs and what it saves

A starter windowsill garden might involve a few pots, a bag of compost and four or five packets of seeds, much of which lasts beyond the first season. In return, you have a steady supply of herbs and salad leaves that would otherwise mean buying small, often wasteful packets several times a week. The exact saving depends on what you grow and how often you cook, but for many households the setup pays for itself within the first few months.

Start with three pots

If you are new to growing, start small: a pot of chives, a pot of parsley and a tray of cut-and-come-again salad. They are forgiving, productive and useful in everyday cooking. Once those are thriving, add basil for summer and a woody herb like thyme. Before long, reaching for a few fresh leaves from your own windowsill will feel completely natural — and the supermarket herb packets will stay on the shelf.