Though shallots and bulbing onions are grown for their bulbs they can be harvested and eaten at any time during their life cycle. When the plants are young – just before and just after bulbing begins – both the white bottoms and green tops can be eaten raw as a salad ingredient. As the plants get older, their green tops get tough and become unsuitable for eating raw, though they are good chopped up and cooked in stews and sauces. The immature bulbs grow larger and can be either eaten raw in salads or used in cooked dishes.
Despite the usefulness of shallots and bulbing onions as young plants, they are normally left to mature and produce full-sized bulbs that are dried and stored for the winter. Each bulb is made up of a fleshy interior surrounded by 2 or 3 layers of a thin, papery skin that protects the inside against moisture loss and disease attack. Further protection is guaranteed by careful handling since bumps will damage the bulbs and affect storage life.
Onions usually mature from August to September, though shallots will do so somewhat earlier. At maturity, the leafy tops will naturally fall over at the necks, i.e., the juncture between the bulbs and tops. The bulbs should be harvested when at least half the tops have fallen. They should be eased out of the ground without being damaged. Once they are lifted, they then need to be dried, which should be done with the green tops still attached to the bulbs.
Drying must be done where it is both warm and dry. A perfect spot is inside a polytunnel or greenhouse, which provides extra warmth and protection from rain. To aid drying, keep the bulbs off the floor by laying them out either on a greenhouse bench, overturned box or wooden pallet. Make sure the temperature inside the structure doesn’t exceed 27ºC, otherwise the skin might split and reduce the chances of long-term storage. Weather permitting, the bulbs can also be dried outdoors, though they may have to be moved inside if the weather turns cool and wet.
Drying is complete when the leaves have lost their green colour and make a rustling sound when disturbed. By then, the neck will be well-sealed, and the leaves can be removed to make storing easier.
Almost invariably, a few plants develop thick necks and won’t die down like the others. To avoid disappointment, it is easier to use them straight from the garden rather than trying to dry them.
Once drying is complete, store the bulbs in a frost-free and preferably well-ventilated place such as a shed or garage. They can be held in plastic mushroom boxes stacked on top of each other, though they can also be packed into nets or, if the leaves are kept on, tied into plaits and suspended to allow air circulate around them.
Stored bulbs come to an end when they start sprouting green leaves. Most onion varieties will keep until March or so, though Long Red Florence won’t last into the New Year, while Ailsa Craig will keep only until February. Shallots are at the top of the storage league table, staying in sound condition well into July.
© Michael Michaud