Spring is the perfect moment to start growing herbs and salad leaves indoors, especially if your balcony or patio doesn't get enough natural light. With an LED grow light, you're no longer limited by season or window position — you can grow fresh basil, coriander, lettuce, and spinach year-round. This guide will walk you through everything you need to know to get started, without breaking the bank.
Understanding Light Requirements for Your Space
Most edible plants need at least 6 hours of direct sunlight daily. In the UK, south-facing windowsills and balconies get the strongest light. If your space only receives 3–4 hours of direct sun, don't worry — leafy greens like lettuce, spinach, and kale are surprisingly tolerant of partial shade and will still thrive.
For year-round growing regardless of natural light, an LED grow light running 14–16 hours daily effectively replaces sunlight. Modern LED panels are energy-efficient and don't generate excessive heat, making them ideal for windowsills and small indoor spaces. Position the light 15–30cm above your seedlings and adjust as they grow.
Getting Started on a Budget
You don't need expensive equipment to grow successfully. Start by repurposing yoghurt pots, egg cartons, or toilet roll tubes as seed trays — just drill drainage holes in the base. I label mine with a set of bamboo plant labels so I remember what I've planted.
Make your own potting mix by combining peat-free compost with perlite and garden sand — it costs a fraction of shop-bought alternatives. Buy seeds in bulk rather than plug plants; a multipack seed collection gives you 8,000+ seeds for £10–13 and covers vegetables, herbs, and salad leaves. Collect rainwater in a bucket — it's free and gentler on seedlings than tap water.
Timing Your Planting
Timing makes a real difference. Sow seed indoors under LED lights 6–8 weeks before your last frost date to grow sturdy seedlings ready for transplanting. In the UK, that usually means starting in late March for late May planting outdoors.
Hardy crops like lettuce and radishes can be direct-sown outdoors from early March. Tender plants such as basil and courgettes should wait until all frost risk has passed, typically late May depending on where you are in the country.
Clever Companion Planting
Growing the right plants together improves yields, deters pests, and makes better use of limited space. Basil planted with tomatoes reportedly improves flavour and repels aphids. Marigolds near vegetables naturally deter whitefly and other soft-bodied pests. Chives and nasturtiums work as sacrificial plants that attract pests away from your main crops. Even in small containers, a mixed-planting approach adds biodiversity and keeps your windowsill more interesting.
Harvesting and Storing Your Crops
Pick salad leaves and herbs in the morning when they're most hydrated — they'll taste fresher and last longer. Use the cut-and-come-again method on lettuce and spinach: harvest from the outside of the plant and the centre keeps growing. You'll get multiple harvests from a single pot.
Fresh herbs can be dried, frozen in oil cubes, or made into pesto for storage. Keep a fine mist spray bottle nearby — misting seedlings regularly keeps them hydrated without waterlogging roots, and it's far gentler than pouring water directly.
Starting small with just a few pots of herbs or lettuce is the perfect way to build confidence. By summer, you'll have fresh basil for pasta, coriander for curries, and crisp salad leaves picked minutes before eating. There's nothing quite like it.