Several years ago while sharing dinner with garden writer friends, the topic turned to our favourite lettuce varieties. We all named vigorous leaf lettuces like ‘Salad Bowl’ and ‘Red Sails’, but then the one among us who owned a seed company went way off script. “I love a good iceberg,” she said, causing me to stifle a gasp.
What? We’re supposed to like lettuces with darker, more nutritious leaves, but here was a respected seed expert saying it was okay to like iceberg lettuce, or at least the garden-grown version. The next season I planted ‘Great Lakes’ iceberg and ‘Sierra’, a colourful Batavian variety that develops dense, elongated heads. My friend had a point. Whether eaten as a wedge, slice, or chopped atop tacos, crunchy crisphead lettuces become delightful treats in the warmth of early summer.
There is a catch. Round-headed icebergs and elongated Batavian crispheads are slower to mature and more exacting in their cultural needs compared to leafier lettuces, which should still hold a prominent place in your garden. But for a special springtime project, growing a few crisphead lettuces can be a rewarding endeavour indeed. Here are a few tips to get you started.
Planting Crisphead Lettuce
Begin by obtaining fresh seeds of an iceberg variety such as ‘Great Lakes’, ‘Iceberg’, ‘Superior’ or ‘Red Iceberg’. So-called Batavian varieties have a similar leaf texture to icebergs, but instead of a round head they form an elongated head with a pale, crisp heart. Green ‘Nevada’ or red-blushed ‘Sierra’ are excellent varieties in the Batavian group.
Stretch the spring season by starting seeds indoors under lights. The ideal growing temperatures for lettuce are 45 to 70°F (7 to 21°C), so try to schedule things so seedlings will have as much cool spring weather as possible. Err on the side of earliness, because you want heads to form before the weather turns hot. Most crisphead lettuces mature about 60 days after transplanting.
Seedlings of both iceberg and Batavian lettuce varieties often start out quite leggy. Pot them up as needed to increase root space and depth, and to keep the little plants steadily growing, but expect the seedlings to be a bit floppy.
In the garden, choose a sunny spot with fertile, well-drained soil, with a near-neutral pH around 6.0. Work a balanced organic fertiliser into the soil along with a generous sprinkling of dried seaweed or kelp to provide extra potassium, which is key to growing flawless heads. Take time to harden off the seedlings for a week before setting them out at least 12 inches (30cm) apart. Use row covers if needed to buffer stiff winds.
Moisture Management for Crisphead Lettuce
Provide an even water supply by soaking the ground between plants every other day. As the plants gain size, try to water in the evening because nighttime moisture improves the supply of nutrients going to the heart leaves. In this way, overnight moisture can help reduce tipburn and other physiological problems, but you don’t want to get plants any wetter than necessary. If possible, use drip irrigation or hand-water carefully between the plants. Should hot weather arrive ahead of schedule, use shade covers to shield the plants from intense sun.
Harvest crisphead lettuce early in the morning, while the heads are cool and plump with water. Trim off dirty outer leaves, and place the heads in plastic bags in the refrigerator. Wait until the day you want to use a head of lettuce to rinse the crunchy leaves.
How to Make Pickled Lettuce
Should you have too many heads, you can make pickled lettuce in a simple brine of 1 cup vinegar, 1/2 cup water, 1 tablespoon sugar and 1 tablespoon salt, with a few cloves of garlic and a sprinkling of peppercorns or dill seeds added. Stuff chunks of iceberg lettuce into a clean jar, pour in the brine, and refrigerate overnight. Don’t worry if the lettuce is not completely covered, because juices will be drawn out of the lettuce which will increase the level of liquid. This is a great side dish for Asian night, or you can use your pickled lettuce on sandwiches.