In the winter of 1996, I made a trip to the Halifax Brewery Farmers’ Market. The upcoming season was going to be my first as a full-time market gardener. I introduced myself to the vendors, hoping to make connections and maybe get some tips on where and what to sell.
One of the more successful organic producers at the market said, “If you want to grow long-season crops like squash, potatoes, tomatoes, go ahead, you might even make some money, but you should know that it’s the greens that will pay your bills.” All season long, greens, particularly the giant heads of leaf lettuce he is famous for, account for the steady sales that makes his long trip to market worthwhile. Many customers buy two heads of lettuce from him every week from May to December. He said that the only way to attract and keep such loyal customers is to offer a top quality product every week.
I listened to his advice. Fifteen years later, greens are still my main crop. Every year I experiment with new techniques and varieties to improve the quality of this finicky class of vegetables. In the spring and fall, bolting is not much of a problem. The shorter days and cool nights allow the lettuce to stand for at least a week once full-grown. In the summer, it’s more of a challenge.
I start lettuce in 1½ inch soil blocks, planning to transplant the seedlings four to six weeks later. For a steady supply of lettuce over the whole season, you have to take changes in day length into account. I start the first seedlings on February 15th for transplanting into an unheated hoop house in late March or the beginning of April, whenever the soil has warmed. I start another batch every three weeks until mid-April. From then until mid-July, I plant every two weeks. From mid-July until the end of August, I plant once a week.
The first outdoor plantings can be made under row cover as early as the ground can be worked. I usually start transplanting without using row cover in early May, but if the weather is still cold, I’ll use row cover to speed up growth and protect against frost damage.
I lay out the lettuce in beds with four rows and plants twelve inches apart in all directions. On sandy, well drained soil, raised beds have not been helpful, but on heavier soil that puddles in the rain, raised beds can make the difference between losing a crop to bottom rot or having an abundant harvest.
If the weed pressure is light, the lettuce will not have to be cultivated at all. Even with a lot of weeds, one cultivation ten days after planting should be enough since lettuce will outcompete most weeds with enough of a head start. My favourite tool for cultivating lettuce is a diamond hoe from Lee Valley Tools. This hoe glides just under the surface of the soil, cutting down small weeds on the push-and-pull stroke.
I like to use the following trick so I don’t have to cultivate at all, even in weedy ground. I spread compost and work the ground ten days ahead of transplanting, then I flame weed using a hand-held torch just before planting. This gives the lettuce a chance to get established in clean ground, saves labour and helps in other ways. Since lettuce has a shallow root system, hoeing around the heads is bound to damage the roots. This is especially true if you water every day, since the root system will be even closer to the surface. I also find that no matter how careful I am, some soil gets into the hearts of the plant when hoeing. Flame weeding prevents both of these undesirable outcomes.
In hot dry weather, make sure the lettuce gets at least one watering a day.
If you are using soil blocks, there’s an unusual option you can choose that will help solve several problems at once: bury the soil block halfway in the ground when transplanting. I first saw an experienced market gardener do this in a greenhouse. He explained that setting the soil blocks just an inch in the ground dramatically reduces bottom rot. This only works if the seedlings are kept very evenly watered otherwise, the exposed top of the soil block will dry out. Even with the best irrigation schedule, I would not try this in very sandy soil. I think this trick also protects plants from cutworms.
In general, the most effective way to beat pests and disease is to provide ideal growing conditions. If the crop is ready to harvest four or five weeks after being transplanted, there won’t be much time for slugs and other pests to do much damage. I always remove the bottom leaves since they are crusted with dirt and often bug-eaten. I don’t consider this a problem. The only times slugs have ruined a crop is when I’ve delayed the harvest a week or two after the plants have reached marketable size. Customers want a large head that is sweet and tender. If it has started to bolt, even a little bit, the taste will be ruined. It seems that bolting is initiated by a combination of three factors: time, heat and drought. To grow big juicy heads of lettuce, especially in the summer, the grower needs to minimize exposure to all three.
Bolting is initiated by a combination of three factors: time, heat and drought.
The way to do this is fairly simple. Make sure the ground is well fertilized, provide ample irrigation, and plant heat-resistant varieties. I find very mature compost that has been kept out of the rain makes the best fertilizer. Even when I’ve had a very limited supply, I use it for the lettuce. Lettuce just seems to appreciate compost more than other crops. With the high return per square foot lettuce brings, I think it’s worth it.
In hot, dry weather, make sure the lettuce gets at least one watering a day. In extreme heat, two or even three waterings can make the difference between no crop and a great crop. On the day of transplanting, I set up sprinklers in the lettuce patch and plan to leave them there until the crop is harvested. For daily irrigation to actually happen, it must be convenient. With good fertility and ample water, lettuce grows quickly. This quick growth is the key to getting your lettuce sized up before it bolts in the summer heat.
It’s best if the temperature of the cooler is set just above freezing, since the colder the lettuce, the longer it keeps.
Most people want normal-looking lettuce. In the Maritimes, this means green leaf, red leaf and dark green romaine. Butterhead/bibb lettuces sell in limited amounts. I find the red butterheads, especially when grown to an extra large size, are so pretty that customers who are looking for something special will buy them. Red Cross is an excellent variety of this type; it’s good for spring, summer and fall plantings.
In the spring and fall, most varieties perform well. For convenience, I use the same varieties for all three seasons. My selection is based on heat resistance for the summer crop. I have limited experience growing lettuce for early winter harvest in a hoop house. For this winter growing, choose varieties bred for cold hardiness.
The best varieties for the heat are the Batavian and summer crisp types. They have thick mid-ribs which are crunchy, juicy and sweet. Most have reddish, bronzed outer leaves. Even though they are beautiful, they are hard to sell in a conservative lettuce market. This is where CSA marketing really shines. Since your customers have already paid for something unusual, they will try uncommon varieties. And once people taste the Batavians and crispheads, they usually like them.
When selling to stores and at farmers’ markets, I have not had much success with unusual lettuces. For instance, one year I grew Trout Back, a romaine with maroon speckles. One of my steady customers was a delightful older English lady. She was sure I had brought diseased lettuce to market. I tried my best to convince her that this was a special variety, but it was useless. She told me that she would have to buy her lettuce elsewhere that week, but would happily return when I had “healthy” romaine back at the stand. Customer feedback like that makes an impact. Lesson learned: no more weird lettuce.
Fortunately, there is Concept. It’s a three-way cross between romaine, crisphead and green leaf lettuce. The amazing thing is that while looking like a green leaf, it has the heat resistance and crunchy sweet mid-ribs of a crisphead. This variety is so good, I don’t understand why it isn’t promoted more.
With romaine, there is an interesting choice. Jericho is by far the sweetest and most heat resistant but it has one flaw—lime green leaves. The standard look for romaine was set long ago by Paris Island Cos: a blanched light green heart with dark green outer leaves. Any variation from this looks ‘wrong’ to most customers. Again, if you are growing for a CSA, this can be overcome. Once people taste Jericho, they will probably love it.
When growing for a wholesale market, I choose Green Forest. It is highly resistant to heat stress, is uniform, and has the classic Paris Island look.
I am still looking for a red leaf that really shines. Red Sails and New Red Fire are both nice, but don’t hold in the field for as long as my other favourites. Also, Red Sails is known to have fragile, brittle leaves, which make it hard to pack.
Harvest is the best part about growing lettuce. It’s so quick and easy. I don’t think there is another crop that comes close in terms of dollars harvested per hour.
I cut the heads with a large knife, trimming discoloured leaves in the field. In an ideal world, all lettuce would be harvested early in the morning, late in the evening, or on rainy days. Often this is not possible. When I have to harvest lettuce while the hot sun beats down, I run the sprinklers for fifteen minutes before I start the harvest. This will keep the lettuce from wilting and greatly increases shelf life.
I cool and wash lettuce in a tank of cold water immediately after harvest. Letting it soak for up to half an hour will cool and crisp the leaves. This will also help eliminate slugs, earwigs and other bugs that may be hiding out. The lettuce is then packed in boxes and stored in the walk-in cooler. It’s best if the temperature of the cooler is set just above freezing, since the colder the lettuce, the longer it keeps.
David’s salad dressing
¼ cup balsamic vinegar
Blend all ingredients and store in the refrigerator. The flavours will mingle after a few days, greatly improving it.
Photo credits: David Greenberg