Outdoor Classroom: twin scaling

photo 1 - Copy1) Twin scaling is a way of increasing the number of bulbs more quickly than by other usual methods. A single bulb can yield up to 30 or more baby bulbs (bulblets) over a period of a season. It only works with proper bulbs – not corms, tubers and rhizomes. Bulbs need a base plate and a layered construction to be twin scaled – eerily similar in form to the common onion shown here.
photo 2 - Copy2) Twin scaling works well for bulbs such as narcissi (daffodils), crinums, galanthus (snowdrops), nerines, amaryllis, hippeastrums, lachenalias and some lilies. Wash the bulb and remove any outside coating and old roots. Make up a weak solution of household bleach – about 1:10 bleach to water – and dip the sharp knife and bulbs. Clean working conditions and hygiene are important to prevent disease and the transfer of any viruses.
???????????????????????????????3) Remove any offsets already formed, making sure you keep some of the base plate with them. The base plate is where the roots grow from. Cut the top third off the bulb (both offset and top are visible to the left in the photo). Cut the main bulb into quarters or eighths, depending on the size of the bulb. Each piece must have some of the base plate remaining attached. The larger the bulb, the more sections you will get.
???????????????????????????????4) Peel off two scales together, attached to some of the base plate. Keep your knife clean and sharp so you can cut through the base of each section more easily. It does not matter if you have three or more scales but if you do not have part of the base plate, the process will not work. A bulblet will form between the two scales on this base plate.
photo 5 - Copy5) Plant the scales in a pot or tray filled with seed raising mix. Press them down deeper than in the photograph until just the tip is visible. Water them in and keep the tray in a warm, reasonably dark position. The bulblets will form through the autumn and grow away in spring so it is best to twin scale when the bulb is freshly dormant. It is too late to twin scale autumn flowering bulbs because they are already starting to grow but you can do the spring flowering ones which includes narcissi such as this bulb.
???????????????????????????????6) If you lack the confidence to take each section down to two scales, you can stop at step 3 where you have cut the bulb into quarters or eighths. As long as you look after them, most sections will grow away into healthy, independent bulbs. It is probably easiest to start with a large bulb while you gain confidence. Most bulbs propagated by twin scaling will take at least two years to reach flowering size, sometimes longer.

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