With the combination of successional sowing, growing under cover and choice of varieties, salad leaves can be cultivated and harvested throughout all seasons.
The days of simply sowing a few rows of lettuces in the spring and summer are long gone. There is a huge array of plants available now that produce leaves with many different shapes, sizes, colours, flavours and textures. Many can still be grown as individual plants and harvested as a whole, but increasingly more are grown as cut-and-come-again crops, or harvested as baby leaves (also known as micro leaves). If you are feeding just one or two people you may find yourself self-sufficient for salad leaves simply by sowing a seed tray or two of mixed leaves every couple of weeks throughout the year.
Salad leaves are quick and easy to grow and you can harvest as much as you need for your meal just minutes before eating, resulting in a far fresher and healthier (and more environmentally friendly) salad than you could possibly get buying leaves from a supermarket. If you cannot harvest immediately before preparing your meal, for example if you have an allotment which you visit only once or twice a week, pack the leaves in a plastic bag, keep out of the sun, and place in your fridge at home as soon as possible. If they look wilted, refresh in cold water.
In addition to the more traditional salad plants there are many others that can be harvested for their young leaves to add to salads, including carrots, cabbages, radish, beetroot, kale, peas, spinach, turnip and chard. If you have some old or excess seeds of vegetables like these, sowing a mixture in a tray for baby leaves is a great way of using them up. Never waste anything that could feed you!
As most salad plants are quick to grow they won’t need special feeding as long as you start out with a good compost. Ideally use your own mix of garden compost with added grit for drainage, but be aware that if your compost has not heated up enough to kill weed seeds you may have trouble distinguishing them from the plants you have sown, especially when growing as baby leaves. You may have to buy in an organic peat-free multi-purpose compost especially for this.
If you wish to grow salad plants to full size you may need to space them 10-20cm apart, depending on the variety. Either raise them in modules then plant out at this spacing, or sow directly more thickly and thin out as they grow, using the thinnings in salads. You don’t necessarily have to wait until the plant is mature before harvesting; with many varieties you can pick off the outer leaves as they grow. For baby leaves, sowing can be much more dense; sprinkling the seed on the compost surface so on average each mini plant is just 0.5cm or 1cm from its neighbour. Cover the seeds lightly with more compost and water.
Almost any container will do for salads; from raised beds to window boxes, troughs, pots, seed trays and so on. The plastic trays that you buy foods like mushrooms in, will be fine for growing small amounts of baby leaves, especially with the smaller rapidly growing plants like cress, mustard, mizuna, rocket and radish. Ideally the containers will need drainage holes so the compost doesn’t get waterlogged; if you are using old mushroom trays indoors you can make holes in the bottom of one and stand it in another, so excess water can drain through into the second one and then be tipped away.
Note that when you harvest baby leaves you can either cut them at stem level (easiest with a pair of scissors) or pick leaves off individually by hand, say one per plant each time. This is a little more time consuming but the plants will produce further leaves for picking another day, whereas if you cut the leaves at stem level, they may not grow back. After a few weeks of harvesting in this way they will weaken and can then be composted before you re-sow the tray in fresh compost. After a while some plants may start to bolt (grow flower heads) even at a small size; these flower heads can also be eaten but it’s a sign that the tray will be coming to its productive end.
Some herbs can also be grown for baby leaves for salads, but bear in mind they can be much more strongly flavoured than other salad leaves, so use sparingly. Those which can be used in salads include basil, coriander, chives, dill, fennel, lemon balm, marjoram, tarragon and parsley (see previous chapter, Herbs).
Growing under cover, whether it’s in a greenhouse, polytunnel, cold frame, conservatory or on the kitchen windowsill, will mean faster germination, protection from frosts and less pest damage. Warmer areas such as the kitchen will be perfect for growing small trays of baby leaves through the winter, but there are also some hardy varieties that will survive in an unheated greenhouse or cold frame as detailed below.
Your sowing schedule will depend very much on what cover is available and what you want to grow. In general, outdoor sowings can be made from mid-March through to September. Cover, such as an unheated greenhouse, can extend the seasons at either end by about six weeks and be used over winter for some crops. Warmer cover, such as a heated greenhouse, conservatory or kitchen, will enable you to grow baby leaves for salads at any time, and will be especially useful over the winter months.
Time now to explore in more detail which plants to grow for salad leaves. We start with good old Lettuces. There are five main types of lettuce: Batavia which have the crispness of an iceberg with the more open growth of a butterhead; Butterhead (e.g. Tom Thumb) which are quick to mature and have a loose heart with soft leaves; Cos (e.g. Little Gem) which produce crisp oval heads and are claimed to have a higher nutritional value than other lettuces; Crisphead (Iceberg types – e.g. Webbs Wonderful) which produce large crisp heads with solid hearts and few outer leaves; and Loose Leaf (e.g. Lollo Rossa) which do not heart up and can be harvested a few leaves at a time as they grow;
Recommended Lettuce Varieties (there are many to choose from, the following is just a small selection of our favourites)
- Batavia (crisp heads like an iceberg, but more open-growing like a butterhead)
- Blonde de Paris – sow spring and summer, crisp green leaves
- Relay – fast growing with red leaves
- Butterhead (mature in about six weeks)
- Tom Thumb – a superb dwarf variety which grows quickly and is slow to bolt, one lettuce is just the right size for a salad for two
- Roxy – red with shiny blistered leaves
- Cos (slower to mature)
- Little Gem – can be sown from spring to early autumn and, under cover, can be eaten into the winter
- Rubens Red – leaves of a deep red over dark green with good texture and flavour
- Crisphead (generally large-growing and slower to bolt when mature)
- Saladin – classic iceberg type, large tight heads
- Raptor – crunchy round heads, harvested spring, summer and autumn, resistant to bolting
- Loose Leaf (harvest individual leaves as the lettuce develops, or entire plant when mature)
- Salad Bowl – curly green leaves, crops over a long period
- Red Salad Bowl – attractive deep red-bronze leaves
- Winter Varieties (sow late summer and autumn outdoors, and also under cover for extended cropping into spring)
- Winter Density – similar to Little Gem but with a larger head, slow to bolt
- Rouge d’Hiver – an old French variety with green leaves tinged with red. Upright with delicious leaves.
In addition to packets of seeds of single varieties, there are now various seed mixes available which are especially suitable for sowing closer together for baby leaves. For example:
- Mixed Lettuce – Red Salad Bowl, Suzan, Marvel of Four Seasons and Little Leprechaun
- MultiSalad Collection – MultiBlond, MultiBaby and MultiRed
- Italian Blend – Rocket, Basil, Oak Leaf Lettuce, Broccoli Raab, Italian Red Dandelion
- Spicy Greens – Rocket, Mustard Green Wave, Mustard Red Giant, Mizuna
- Asian Leaves – Suitable for both salads and stir-fries: Bok Bhoy, Mizuna, Mustard Purple and Golden Frills.
Other salad plants that can be grown from seed include:
Chicory – Leaves have a bitter-flavour which can be reduced by harvesting as baby leaves. Varieties: Rossa di Treviso (radicchio type with long red leaves), Sugar Loaf (hardy plants with sweet conical heads).
Cress – Perfect for growing on a windowsill throughout the year. Varieties: Cress (line containers with kitchen paper and keep moist, ready to harvest in just a couple of weeks), American Land Cress (easy to grow with a flavour like water cress), Water Cress (keep containers well watered).
Endive – Similar to lettuce but with slightly bitter leaves, can be grown year round (under cover in winter). Can be harvested as cut-and-come-again plants. To blanch the leaves and reduce the bitterness simply cover the plant with a pot, to exclude the light, a few days before harvest. Varieties: Blonde Full Heart (large green curly leaves), Extra Fine de Louviers (miniature plants that grow quickly to produce finely curved leaves).
Lambs Lettuce also known as Corn Salad – Small plants, great for containers, high in vitamin C. Varieties: Vit (can be grown throughout the winter), Baron (fast growing).
Mustard – Spicy flavoured leaves, can be cut as baby leaves or grown on for larger plants. Varieties: Mustard Giant Red (attractive red leaves), Zlata (grow on a windowsill like cress), Mustard Purple Frills (fast growing producing delicate thin leaves).
Oriental Leaves – Fast growing plants originating in China and the Far East. Varieties: Mizuna (attractive narrow leaves with a slight mustard flavour), Mibuna (long thin leaves with a stronger flavour than Mizuna). Note that other oriental vegetables such as Chinese Cabbage and Pak Choi can also be cut while young and used in salads.
Pea Shoots – Quick and easy to grow, harvest the shoots while just a few centimetres tall and use raw in salads, sandwiches or as garnishes. There are many varieties of peas and all can be grown for their young shoots.
Rocket – Will grow outdoors for much of the year and under cover over winter. Varieties: Rucola Salad Rocket (rich spicy flavour, grows well in pots), Rocket Esmee (ready in just 30 days, slow to bolt, great flavour).
All pages in this Garden Advice section are written by Piers Warren with extracts from his book The Vegan Cook & Gardener.