Summer salads: lettuce and other leafy greens

Article originally published by: Kiwi Gardener

Learn the tricks of the trade to keep your greens cool this February.

In the hottest months, when salads are frequently on the menu, it is time to pump out as many lettuces through your garden as possible. Think of lettuces as being like athletes – they need a few essentials to make the cut.

Understanding what the event conditions will be like helps determine what training regime should be used to get the best results.

In summer, leafy crops can be a challenge as the sun naturally saps the moisture (and the will to live) out of anything with a large, juicy leaf surface. Understanding this and working with the elements rather than against them will ensure you get the winning results.

Cos is a favorite with many for its crisp texture and robust habit.

Soil matters

To avoid bitter hard lettuces you will need to do some ground work before new crops are planted out. Lettuces and other leafy salad greens require a soil that has a lot of organic matter blended into it – especially in summer. The go-to options are well-rotted animal manure and compost; sphagnum moss or peat works a treat, too. To get the best results dig a 10cm layer into the soil before planting, and then soak the area well before going near the soil with your new seedlings.

This step is often missed as we are all in a hurry to get our plants into the ground. However, pre-soaking the soil provides a lovely moist environment for the plant’s roots to nestle into, which helps limit transplant shock. This is particularly important in the hottest months; compost and manure act as a sponge to allow the soil to hold onto more moisture. If you leave this step out, you may well struggle to have the summer salads you are after.


Athletes cannot perform without hydration and lettuces are no different. Regular water will ensure your crop makes the grade. Ideally, drench your crop two to three times a week, avoiding the trap of watering a little every day – as all this does is encourage the roots to stay near the soil surface, where they can easily get burnt. Drip-line irrigation works well, too. A drench of a seaweed tonic will give them a welcome boost each month.

TOP TIP: Aim to water the soil around the plants rather than the foliage.

L: Dad’s favourite, ‘Great Lakes’ hearting lettuce | R: Frilly lettuces are great options for planters and containers. Teamed up with eggplants they look a treat.

Planting: Make it a no-brainer

The best time of day for planting is when it’s cooler – a little bit like training for a run. It’s easier when it’s cooler, so try for the morning or evening, unless it’s a cool day. Avoid planting in the middle of the day; transplant shock is the biggest cause of crop failure. It goes from being a low-stress procedure for the plant to being a struggle from the outset – a bit like starting a race with an injury.

Sun protection

For 80 per cent of the year your salad crops need as much sun as possible, but in the hottest six to eight weeks of the year, a little protection from the intense midday sun will be welcomed by leafy greens. Morning or afternoon sun is enough for summer lettuces, so if you have the option to plant them in a part of the garden that only gets half a day of direct sun, go for it. An easy alternative to this is to grow them in pots and planters. As these are portable, you can place them in an area that gets just the right amount of light.

White shade cloth or even old net curtains can also provide welcome protection from the intense heat. This is easy to erect by draping it over some bamboo canes. It can be left on all the time, especially if it is well-secured. Use rubber bands on the top of the stakes to keep it in place.

Mulch is your mate

Straw mulches are awesome to use in and around summer lettuce and salad crops. Because the straw is such a pale colour, it reflects the sunlight, which in turn helps keep the soil cooler as well as helping it retain its moisture. A layer of straw even helps in pots and planters. If you have a small garden, you do not need to get a whole bale of straw, just look for the little strawberry straw packs – these fluff up to go quite a long way. It’s super easy to use and it lasts for a good 12 months. Avoid bark or dark mulches as the dark colour attracts the heat.

Seed vs seedlings

In the middle of summer, the soil temperatures can get too hot for a reliable germination of lettuce seed. Therefore, either sow them in trays in a cooler spot, or look to plant seedlings; the shops have loads of plants in stock.

L:‘Buttercrunch’ is a lovely loosehearting variety | R: ‘Little Gem’ is a crisp, super-sweet one to seek out. Wonderful for smaller gardens.

Which ones to choose

Fancy & frilly

How good do frilly lettuces look? For looks alone they are worth planting. I always feel healthy just looking at them. They are ideal to grow in pots and tubs as they are slightly more robust to the elements. That doesn’t mean you can get away with not watering them though, they are still lettuces and need their ‘TLC’ (Tender Lettuce Care).

Plant just over a hand-space apart – approximately 15cm. Aim to try and harvest the biggest ones first: this allows the smaller ones room to move. Mixing up the red- and greenleafed types looks pretty; try pimping out your pots and planters with some edible flowers like nasturtiums or calendula. Mix in some parsley and chives and you will have yourself a salad garden.

Just cos

Crispy cos lettuce is a stalwart in my garden all year round. I often use it as a cut-and-come-again lettuce, picking it leaf by leaf as I need it. When I do harvest the whole plant at once, I cut the head off just above ground level and leave the stalk in the ground. A few weeks later a new flush of leaves appear; although these are not as sweet as first main crop, they make a great filler to mixed green salads.

Cos does prefer a little protection from the intense sun in the middle of summer, so if you do not have a cooler spot, grow it in tubs. Plant 15-20cm apart.

Mix up your plantings with colourful contrasting lettuce varieties.

Hearty by nature

My father is never without hearting lettuce in his garden and his fridge is never without his homemade egg mayonnaise. No flash vinaigrettes on this old farmer’s table. His go-to ones for summer are ‘Webb’s Wonderful’ or ‘Great Lakes’. Both are super hybrids that form large hearts. Being a dairy farmer, he has a continuous supply of cow poop, so once a year his patch gets a tractor load dumped on it from the bottom of the cow yard. This nitrogen-laden goodness actually has no smell, because it’s so well rotted. It helps the soil hold onto all that valuable moisture through summer allowing his heading lettuces to keep ticking over. The trick with hearting lettuces is not to over-crowd them, because if water gets caught up in the large outer leaves it has nowhere to drain to, which will cause the plants to wilt and rot. To avoid that happening, plant seedlings a trowel distance apart (at least 30cm apart).

‘Buttercrunch’ is a favorite hearting one of mine, with soft lime-green leaves forming a loose head. This one has a sweet taste that rarely gets bitter.

Tiny & tasty

‘Little Gem’ is one of the best smaller lettuces you will ever grow. I have been growing it for years and have it in the garden all year-round. I plant a punnet or two once a month. It forms dense, tight heads of super-crisp sweet leaves in a very short period of time. Each stem looks like a little chalice, making it an ideal one to grow for those foodies among you who like to serve small bite-sized treats in a lettuce cup. It’s one of Jamie Oliver’s favourites, and it will come again if you leave a piece of the stem in the ground.

L: Plant a tub of lettuces at your back door – it’s like ‘meals on wheels’ without the car! | R: Sow lettuce seedlings in recycled produce containers somewhere cooler in summer. This helps trigger germination.


For the best flavour and crunch, pick as close to eating as possible. If you need to pick your lettuces to prevent them from bolting, pick them in the morning, rinse with water and place in the vegetable bin of the fridge or in a sealed bag. They will keep for well over a week.


Yes, slugs and snails are still kicking about. In fact, whenever there is a reliable food source they have no need to move on. To avoid them munching through your dinners and lunches keep up with the slug and snail pellets. For a natural alternative, eggshells and straw mulches work as well.