Salad leaves are one of the easiest crops to grow in a container. They need little space, grow quickly and can be picked over several weeks rather than all at once. A single trough or deep planter on a balcony can supply a steady bowl of leaves for much of the season. This article explains how to choose varieties, sow and thin, harvest correctly and keep the plants productive. The method is known as cut-and-come-again, because the leaves regrow after each cut when the plant is cared for properly. It suits small spaces and busy households alike.
Choose a container and a mix of leaves
A container for salad leaves should be wide and reasonably deep, with drainage holes along the bottom. Leaves do not need extreme depth, but they do need enough soil to hold moisture between waterings. A window box or long planter works well on a balcony rail. Choose a light potting mix and fill the container to just below the rim.
For variety, combine a few types of leaf with different textures and flavours. Loose-leaf lettuce, rocket, chard and mustard greens grow well together. Mixing them also spreads the harvest across the season, because some leaves mature faster than others.
Sow in rows or small patches
Sow seeds thinly along shallow drills or scatter them across the surface and cover lightly. Many salad leaves germinate within a week in warm conditions. Thin the seedlings once they are a few centimetres tall, so that each plant has space to grow. Thinning is important, because crowded leaves struggle and can become bitter. The thinnings can go into a salad straight away. Helpful points to remember include these:
- Sow little and often rather than all at once, for a continuous supply.
- Keep the soil moist during germination, but never waterlogged.
- Thin seedlings early so the remaining plants have room to develop.
- Label rows or patches so you know which leaves are ready to pick.
- Start a fresh sowing every few weeks in mild seasons.
Water consistently and protect from heat
Leaves are mostly water, so they react quickly to dry soil. A container on a balcony can dry out in a single warm afternoon, leaving the leaves tough and bitter. Water in the morning when possible, and check the soil by pressing a finger into it each day. Water at the base rather than over the leaves, so that the foliage stays dry. In hot spells, a light shade cloth or a position that receives shelter from the afternoon sun can make a real difference. Readers may also want to visit pure-kanagawa.com.
Mulching the surface with a thin layer of fine compost or shredded leaf material can slow evaporation. Keep the mulch away from the stems to avoid rot, and renew it as it breaks down.
Harvest the outer leaves first
The secret of cut-and-come-again is to harvest carefully. Pick the outer leaves first, when they are large enough to eat, and leave the younger inner leaves to keep growing. Cut with clean scissors just above the base of the stem, or pull individual leaves gently. Avoid stripping a plant completely, because it needs some foliage to keep growing and regrow. You can also visit hostistry.com for more reading.
Harvest in the cool part of the day when possible. Leaves picked in the morning are crisp and hold their moisture better. Once picked, rinse them in cool water, dry them gently and store them in a sealed bag or container in the fridge.
Keep plants productive for longer
After several weeks, most leaves will start to slow down, become bitter or send up flower stalks. This is a sign that the plant is changing its priorities. You can often extend its life by cutting the stalks back, feeding lightly with a balanced liquid fertiliser and keeping the watering steady. When the crop finally fades, clear the container, refresh the potting mix and sow again. For a related read on this site, see How to Cook Regional Plant-Based Meals in Holiday.
Growing salad leaves in a single container is a satisfying way to bring freshness to the table. A little sowing, careful thinning, regular watering and gentle harvesting can keep a bowl full for much of the year. Keep a small notebook beside the planter to record when each sowing went in and when the first leaves were picked, because the notes make it easy to time the next sowing. Many gardeners also find that turning the planter every few weeks helps the leaves grow evenly, particularly where light is uneven across the balcony. The method asks for attention rather than space, which makes it ideal for a balcony that can only hold one good planter.
