Slugs and Salal: Veggies

Lettuce

[ sowing indoors | outdoor seeding | transplanting | container culture ]

My longstanding fascination with the many faces of lettuce is fed and fanned anew each year with the arrival of the seed catalogues. Always, I know, there will be fresh and intriguing varieties to try alongside an established repertoire of favorites. Some of the new lettuces will eventually be added to my stable of top performers. Others will be dropped after a trial of two or three years. In this entertaining and pleasurable process, the garden's history of lettuce growing continues to evolve.

As it does, I'm aware that the culture of this ancient and venerable vegetable forges a link backwards as well, between my ongoing preoccupation with lettuce and the roots of its culture in gardening history.

The ancient Egyptians cultivated a tall cos type lettuce, four forms of which are mentioned in Greek literature. The name Cos comes from the Greek Island of Kos, where the Romans discovered the plant. Cos lettuce became so popular and widely grown in Rome that it eventually was identified with the city. From that association came the term romaine.

It was in the hands of ancient Roman gardeners that the process of selection developed many beautiful forms of lettuce. And it was in ancient Roman society that lettuce came into prominence as an important food. With the coming of the Romans to Britain, lettuce was introduced into the Anglo-Saxon culture under its Latin name Lactuca sativa -- Lactuca for milk, a reference to the white juice that exudes from cut stems, and sativa indicating a cultivated plant. The Saxons called it lactuce.

Few other plants illustrate so well the old garden adage "Fat soil: fat plant." A humus-rich, moisture- retaining soil is the necessary foundation for those full-bodied, fine-flavoured lettuces that so delight the home gardener and salad lover.

Gerard's Herball, published in 1597, states the essence of lettuce culture nicely. Referring to ancient garden writers, Gerard says this: "Lettuce delighteth to grow, as Palladius saith, in a mannured, fat, moist, and dunged ground: it must be sowen in faire weather in places where there is plenty of water, as Columella saith, and prospereth best if it be sowen very thin."

YEAR-ROUND PLANTING

I begin the lettuce year with an indoor seeding in late January or early February, for transplanting into frames or under cover in February or March depending upon the kind of winter it is. For this first seeding I use mainly cold hardy butterheads and sometimes selected leaf lettuces. It yields usable lettuce beginning in the second half of April.

At the same time that I transplant these into frames or under a cover of Reemay I seed corn salad -- not a lettuce but a small, cold-season, lettuce-like plant whose mild, sweet flavour and soft, chewy texture I deem indispensable for spring meals.

In late February or early March I seed a second batch of lettuce for transplanting into the open garden in late March or early April. This seeding includes a sampling from among the romaines, butterheads and crisp head lettuces, and will yield an extended harvest.

As the season advances, I select from among the more heat-tolerant lettuces for seedings to be transplanted from mid-June through early August. These are to be found mainly among the leaf lettuces, the romaines, and some of the intermediate types.

The last lettuce seeding I make is an outdoor one, just before mid-August. The varieties are mainly cold hardy butterheads, some fast and some slow to develop, for a lettuce harvest from November through early April. I aim to transplant the results of this open garden seeding into frames and under row covers in late September or early October, before the first light frosts arrive.

Sowing lettuce indoors

It's my own preference to sow lettuce seeds indoors, in small batches about every three weeks, for transplanting outdoors roughly a month after seeding. This gives me better control over the plants' beginnings, an especially important consideration both at the beginning of the season, when an indoor sowing allows time for the soil outdoors to lose some of its winter chill, and also in warm summer weather, when it's easier indoors to supply the cooler temperatures needed for a sound seedlinghood in lettuce.

Because I plant at least a half-dozen different lettuce varieties at each indoor sowing, I use as seeding containers three by five inch (7.5 by 12.5 cm) plastic flats that I've purchased transplants in, or one-quart (one-litre) milk cartons with a side cut out, the pouring lip stapled together and drainage holes poked in the bottom. These small recycled flats are large enough to accommodate the five or six young transplants that I want of each cultivar.

First I make sure the seeding containers are scrubbed clean. Then I fill them with a sterile soil- based mix made of roughly two parts packaged, sterilized soil, one part peat moss, and one-half part each vermiculite and perlite. The only fertilizer I mix into the seeding blend is a little bone meal at the rate of about two tablespoons to every two-gallon bucketful of the blend.

Once a flat is filled, not quite to the top, with the seeding blend pressed gently down, I water thoroughly with a warm seaweed fertilizer solution mixed at label rates. Then I arrange the lettuce seeds sparingly over the damp surface, and cover them just barely with more mix, gently pressed down and spray-dampened with more seaweed solution.

I usually arrange the flats in some sort of holder, which can be anything from an old plastic tray to a shallow computer paper box lined with a plastic grocery bag. A sheet of clear plastic floated over the flats helps to hold moisture in the mix during the germination period. If there is room under my plant lights, that's where newly seeded lettuce flats go. Lettuce seed germination is enhanced by light, together with normally warm room temperatures. With germination, the plastic cover comes off.

The best lettuce transplants develop from a seedlinghood spent in bright light and cool temperatures ideally in the 60 to 65 F (15 to 18 C) range. This is a combination of conditions not always easy to achieve. I find it on the bottom level of my three-tiered plant light stand, which is not warmed by any lights below. But cool basement rooms with a bright window will provide similarly congenial conditions.

As the seedlings develop I thin them by degrees, keeping the most robust and stocky specimens in each flat. In three to five weeks from seeding, depending upon the variety and the season, a flat of lettuce will be ready to transplant. I monitor the flats closely, and as they approach transplanting size I set them outdoors, on wire benches set up along the north side of the greenhouse, for about a week prior to transplanting.

Catching lettuce at its optimum stage for transplanting is not difficult. The plants should have advanced past the frail wispiness of seedlinghood into plump, easily handled mini-rosettes of small leaves. When past their transplanting prime, lettuce plants begin to climb out of their flats on long stems.

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Outdoor seeding

Before seeding or transplanting lettuce into a garden site, I dig into the soil a three-inch (eight-cm) layer of compost or composted manure, or a blend of both, together with a natural-source fertilizer applied at the rate of a large handful over every square yard (metre).

Pre-blended, natural-source fertilizers are becoming increasingly available to home gardeners these days. I purchase the ingredients at a farm supply outlet or garden centre, and mix my own. My all-purpose, home-mixed fertilizer formula that I have used in the garden with great success combines four parts seed meal (I use canola), one part dolomite lime, one-half part bone meal, and one-half part kelp meal. The measurements are by volume, each part being a scoopful, a tinful, or whatever container you choose to measure with.

This formula gives a fairly even balance among the three major nutrients, and it can be adjusted to suit different soil conditions. If you know, for example, that your garden's soil is undersupplied with nitrogen, increase the amount of seed meal a little, as this ingredient is the major source of nitrogen in the formula. Bone meal supplies mainly phosphorus, kelp meal potassium as well as a multitude of trace minerals.

Once a humusy material and a fertilizer have been mixed well into the soil and the surface has been raked smooth, you are ready to plant. Sow thinly into shallow furrows a scant quarter-inch (6 mm) deep, and firm the soil gently over the seeds. I use the blade of a hoe to tamp the soil down.

Do not let the soil surface dry during the germination period, and keep the soil consistently moistened throughout the lifetime of lettuce plants, which have shallow root systems that place the plants at the mercy of conditions in the upper soil layers. Ample humus in the soil helps retain moisture.

For well-nourished, fully-sized heads and rosettes of lettuce, the seedlings will need to be ruthlessly thinned. Miniatures such as Little Gem and Tom Thumb will develop fully with a mere six-inch (15-cm) spacing, while the large crispheads and butterheads will need twice that space.	Butterhead 'Nancy' lettuce needs space to develop fully.
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Transplanting

Transplants are also a great convenience in a crowded garden. Except for the early forcing and fall/winter lettuces in frames and under row covers, I rarely give lettuce its very own garden space. Instead, as a lettuce sowing approaches transplanting size I seek odd spaces to receive the plants. That period of growth into transplanting size buys me time for likely spaces to develop or become free in the garden.

Early in the season this might be along the bases of just-sprouted pea rows, in between cabbage transplants, or in circles around future squash sites. Later, as the weather warms, I seek ever cooler spots such as on the shaded side of staked tomatoes, Brussels sprouts or pole beans. In assessing sites for lettuces to mature in summer, I look not only for this shelter from heat but also for sites that are easy to keep amply moistened.

Where lettuce transplants are to be set out in beds of their own, prepare the soil as for direct seeding. If, on the other hand, the transplants are to be tucked in here and there amongst other, slower-growing vegetables, just the immediate planting site needs to be plumped. I begin by taking out a deeper planting hole than I need, and tossing into it about a tablespoon of natural-source fertilizer along with two or three broad trowels full of compost or composted manure, or a combination of the two.

After mixing these amendments well into the bottom of the planting hole, I settle a lettuce transplant into the site and partially fill in the hole. After a few transplants are semi-installed in this manner, I puddle them in with a mild solution of fish and seaweed fertilizers combined. Then I firm the soil well around each plant, and scuffle the surface lightly so that the packed soil won't shed water.

Often, lettuce transplants need a slight trimming prior to being settled into their garden sites. I usually pinch away any leaves below the central rosette of foliage, which should end up just resting on the soil surface. In this way, even if a transplant has gone a little leggy, the lankiness is conveniently hidden beneath a forgiving cover of soil.

I save eggshells, crushed into old coffee tins, over the winter for placing in lines around lettuce transplants. This has worked well for me as a slug barrier.

Eggshells are a good, environmentally friendly slug barrier for lettuce transplants.

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Container culture

For patio and balcony gardeners who would like to grow lettuce in pots and planters, be sure to use a container that is sizeable enough so that the soil does not heat up much or dry out quickly in warm, dry weather. Aim for a minimum eight-inch (20-cm) soil depth, and locate the container where it will be protected from hot sun.

You'll have the most gratifying luck in containers with leaf lettuces, the smaller forms of romaine such as Little Gem, Diamond Gem and Red Leprechaun, and Tom Thumb, a dwarf heirloom butterhead. A mixture of different forms, some plain green and some red-tinged, gives something lovely for the eye as well as the palate.

For top quality container-grown lettuce, use a robustly-textured, moisture-retaining soil mix. If you use a lightweight, purchased mix add a little packaged, sterilized soil and some processed manure to beef it up. And keep the soil mix consistently moist.

Leaf lettuces are fast-growing, and you can begin harvesting the outer leaves while the plants are young. They'll continue producing new foliage from the plant centres. As you harvest whole plants from a container bed of lettuces, mix in a little fresh soil and pop in a few more seeds or transplants. One way to maintain continuous lettuce production is to start another small batch of seeds indoors each time transplants are moved into a container.

Radicchio, Italian chicory, while not of the lettuce family, is an increasingly popular salad green often used with or
instead of lettuce.

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