There is hardly a recipe that doesn’t begin with chopping, dicing, or slicing an onion. The ritual peeling of the outer skin and the consequent penitent tears are a requirement for any cook intent on accenting complimentary flavors and supporting the role of more timid ingredients. Although this pedestrian vegetable often sells for marginal prices, the variety in the genus Allium allows the market gardener to diversify selection by growing the more royal members of the family, which command a much better price at close to the same production cost as regular onions. Three of the most popular alliums, both in the restaurant and retail trade, are shallots, cipollinis and leeks. Each occupies its own particular niche, both in the field and on the table, and they illustrate the potential of expanding a narrow market. These are not just fancy onions. As John Paul DaMatto of Mio Restaurant in Washington D.C. would say, “Who wants crappy pearl onions out of a jar when you can have a fresh cipollini. They have the sweetness of a Vidalia without the bite.” Spoken like a true Italian.
From the farmer’s perspective the value of these allium species is not just from the higher price that they command. They also afford a more continuous harvest of a specialty crop throughout the season. Although propagation begins at the same time, the combined harvest dates can stretch from early June to the end of December, and into the next year if storage and over-wintering methods are successful.
Propagation
Propagation methods of alliums are as diverse as the number of species. Leeks, shallots and cipollinis can all be started from seed, which affords the least expensive and most reliable propagation method available to the farmer. Shallots are also commonly grown from sets which make planting a simpler task in the spring; but the volume of sets needed to get a significant crop is economically prohibitive. Spring planting of sets is feasible if you want only a small patch. It is also possible to plant shallot sets in the fall for the next summer, but there is usually significant winter kill in the northeast and those that do survive may bolt in the spring and produce an unappetizing woody bulb.
Alliums can be direct seeded, but the fields must be relatively weed-free. Onion seed tends to germinate fairly quickly under optimum conditions but dry spells can inhibit germination. The seedling is fairly delicate in the first stages of growth and is susceptible to wind damage and attacks from early generations of onion root maggots.
Starting onions in the greenhouse assures maximum germination and a more reliable crop than direct seeding in the field. New onion seeds usually have very high germination rates (89% to 96%), but viability is lost within a year, so old seed should be discarded. For cipollinis and shallots, seed into plugs – size can range from 100 to 200 count depending on space constraints in the greenhouse. Larger cells will encourage root growth and the added vigor will reduce transplant shock.
Planting any small seed into plugs can be tedious work, so if you’re planning on producing significant acreage of onions a vacuum seeder would be a good investment. Planting is precise and can significantly reduce wasting seed by planting too thick. (Shallot seed is especially expensive ranging from $75 to $125 per 5,000 seeds, depending on the source.) Two to three plants per cell is optimum for shallots, although they can be sown thicker if you want smaller bulbs. Cipollinis can be sown up to four per cell since smaller onions are highly prized by chefs for cooking whole. If you seed by hand you should later thin the cells in the greenhouse or harvest some of the early crop as scallions to encourage development.
Although leeks can also be started in plugs deep flats or beds in the greenhouse are preferable since the plants will later be laid out into the field individually. Sow thickly in single rows and grow up to pencil thickness. If you have a greenhouse where you grow vegetables for crop production rather than plant propagation, this might be a good method to grow baby leeks in the off season. When allowed to grow to this size leeks should be trimmed (roots and leaves) to facilitate transplanting. Cut enough of the leaf to prevent them from being buried during the planting process and leave at least two inches of root. Leek roots are incredibly vigorous and will grow as deep as the soil medium. In shallow flats they tend to become stunted and will often become susceptible to damping off if left in the flat too long.
Cultivation
For best weed control shallots and cipollinis should be planted in plastic – four rows on a 36” bed with a 3” to 4” spacing between plants. Since the roots zones are fairly narrow a minimum of two drip lines should be used for irrigation. Using a standard transplanter is the most efficient method of getting them into the ground and reducing the amount of exposed earth. Unfortunately, the shear number of holes in the plastic will expose a large surface area of bare ground to the light almost guaranteeing the instant and vigorous germination of weeds seeds. To minimize this first flush of weed seeds lay the plastic well in advance of transplanting. Plastic can even be laid the fall before for early transplanting in the spring. It’s crucial to keep weeds down at their very earliest stage of development because weeding out large plants later in the season can damage the tender growth of the onions exposing them to a myriad of bacterial and fungal diseases. These diseases are most often manifested during postharvest curing.
Leeks can also be grown in plastic but the traditional method is to plant in bare ground and cultivate between rows. To achieve blanched stalks hilling is necessary and can be done during cultivation. Since the roots of leeks are very vigorous and tend to spread more than other alliums, care should be taken not to disturb them during cultivation. Planting in shallow trenches and filling them in during the season helps prevent too much root damage.
Pests and diseases
There are a number pests and diseases that affect alliums, but most can be well controlled in small plots. The most common insect that attacks the onion family is the root maggot. The egg is laid by a small fly at ground level at the base of the plant. Frequent cultivation helps disturb their breeding cycle – another good reason to hill leeks. Shallots and onions usually manage to avoid damage from the root maggot because they are harvested before the late breeding cycle. Leeks are particularly susceptible to the root maggot because they spend so much more time in the ground. Monitoring the patch with yellow sticky strips can help identify the time when the fly is most active. Densely placed sticky strips can also have a significant impact in reducing infestation.
The most common diseases of onions are generally soil borne and exacerbated by wet or humid weather. Many of these diseases are not apparent until after harvest and can often be caused by improper curing. Among the most common diseases are slippery skin, sour skin, soft rot and neck rot, all bacterial infections that can take place in the field when the plant looks healthy. Infection often occurs at a broken leaf or scar from cultivation. The first line of defense against these diseases is proper rotation. It’s difficult to insure that fields are 100% free of infected debris after harvest, so a minimum three years rotation with at least one year of unrelated cover crop will have a significant impact on reducing the carryover of these diseases. Avoiding damage to the leaves while weeding (as mentioned previously) cannot be stressed enough in preventing infection.
Of course, harvesting any onion in its fresh stage will almost guarantee a healthy crop since bacterial infections have less time to manifest themselves. This is especially true of cipollini onions which are grown almost exclusive for fresh harvest. Shallots, on the other hand, seem more susceptible to disease than other onions and greater care should be taken when curing and storing.
There are a number of excellent information sources on onion diseases and pests available through the internet. They are easily accessed through search engines. Below are two examples:
http://plant-disease.ippc.orst.edu/disease.cfm?RecordID=751
http://www.omafra.gov.on.ca/english/crops/facts/95-063.htm
Preparation for fresh market
Leeks, Shallots, and Cipollinis all occupy different marketing niches and have distinct harvesting requirements. Shallots and cipollinis are the most similar in growing habit but they are generally treated differently for marketing purposes. Both can be harvested fresh or cured, but cipollinis are traditionally harvested in fresh bunches. They can be picked fresh for a number of weeks while the necks are still upright but they will eventually fall over as they come closer to the end of their cycle. Planting varieties with different day lengths will stagger the harvest and extend the season. (Bianca DiMaggio and Gold Coin excellent complementary varieties with harvest dates about two weeks apart.) Chefs generally prefer the smaller cipollinis (1 to 2 inches); but larger ones can also be sold for the retail market. Bunches should be sized appropriately based on customer demand – 6 to 8 small ones for restaurant trade; 3 to 5 large ones for retail. A case of 12 bunches can sell for between $25 and $30 on the organic market.
Shallots should be cured like a regular onion and stored in a cooler only after they are fully cured. Although shallots have been more widely grown in recent years the demand is still greater than the supply assuring a higher price than common onions ($15 to $20 for 5 lb box.) As with onions, curing of shallots is most often started in the field. As the plants begin to die back and the neck softens, push down the leaves with a rake or hoe to help the process along. Often the onions are pulled out and allowed to cure further in the sun, but care should be taken if temperatures approach 90Ëš F with high humidity. Onion harvest often occurs at the hottest point in the summer and sun scald can completely ruin a crop in a matter of hours. If you notice the skin becoming translucent, be assured that a white scar will appear in a few weeks making the onion or shallot unmarketable. Bringing the crop in before they are fully cured and laying them out on racks will help insure that the previous three months were not just a compost building exercise.
Two main varieties of shallots dominate the market – French Red and Dutch Yellow. When offered side by side the red shallots tend to outsell the yellow. But both have strong followings among chefs and should be offered together to satisfy the idiosyncrasies of the market place. Ambition is the most common red shallot available in seed from a number of sources, but it would be well worth checking out the new Johnny’s Selected Seed catalog for newer varieties that are becoming available.
Leeks are unique in the onion family since they are not restricted by day length in their development. They can be picked fresh as long as the ground isn’t frozen and many varieties can be over-wintered for spring sale. As with the fall planted shallots these over wintered leeks will bolt in the spring, so they should be harvested and sold as quickly as possible. If they begin to bolt the stalk will become hollow and tough. On the wholesale market leeks are generally sold in 20 lb. cases and can range in price from $32 to $42 per case depending on the season. For the retail market it’s often convenient to tie leeks in 1 lb bunches.
Harvesting leeks can begin as early as mid August if you use a variety like King Richard – a reliable standard for the fresh market. The strength of the root system becomes evident when picking for market and it is not uncommon for the farmer to lose the battle and wind up impaled on a neighboring tomato stake. Using a fork or shovel, especially under dry conditions, is a necessary part of the harvest arsenal. Trimming leaves and roots in the field takes extra time but is worth the effort to reduce debris in the packing shed. Care should be taken not to shake dirt into the crowns of the standing leeks.
But the main concern when harvesting leeks (or fresh cipollinis for that matter) is not agricultural – it is social. Just as the chef is accosted by the tearful pungency of a fresh onion, the farmer is subject to the inevitable fate of smelling like a soup ingredient for extended periods of time. Even protective clothing is not enough to prevent the essence of leek from permeating the flesh and exuding a questionable aroma that can persist for weeks. Even my dog walks ten feet in front of me during leek season. And at the end of a long day of picking when exhaustion has desensitized my olfactory sense, I am confronted with this sign at the kitchen door, “Please remove and burn all articles of clothing before entering.” Just one of those hidden costs no one likes to talk about.
Tony Ricci owns and operates Green Heron Farm in central Pennsylvania with his wife, Becky Smith. They are members of Tuscarora Organic Growers Coop, where Tony also serves as the sales manager.
Copyright Growing For Market Magazine.
All rights reserved. No portion of this article may be copied
in any manner for use other than by the subscriber without
permission from the publisher.