Wait! Before you put those tulip, daffodil, crocus and hyacinth bulbs in the ground, do you want to multiply them?
Sure, they'll multiply by themselves, but you can speed up the process.
Bulb or corm?
Before you can multiply a bulb, you have to know if what you have in hand really is a bulb. Some so-called bulbs, such as crocus and gladiolus, are in fact corms, which are just thickened hunks of stem.
If you want crocuses to multiply prolifically, make cuttings, as you would with any stem. Each cutting needs at least one bud, or eye, best seen on a corm by removing the papery covering. Because of all this wounding and the difficulty of seeing the eyes at this time of year, perhaps you should wait until early spring to cut up crocus corms. Wounds heal most quickly then, and eyes are plumping up.
Corms can also be propagated another way, with cormels. These are baby corms, produced around the base of a corm. Plant your crocus shallower than recommended and you'll get more cormels.
Most other common spring bulbs are true bulbs, consisting of a foreshortened piece of stem with the bulk of the bulb made up of layers of leaves, scales or both. As with your forsythia or rose bush, buds grow wherever leaves meet a stem. In bulbs, these buds become bulblets, which grow up to become first offsets and then bona fide bulbs themselves.
One way to multiply bulbs is to just dig them up sometime between early summer and now, and then snap off and plant out the offsets. Not having to elbow around in the dirt with their mother bulb, bulblets or other offsets lets these separated offsets grow quickly to flowering size, and make more of their own bulblets and offsets.
For greater increase, make bulb cuttings of such beauties as daffodils and squill. Bulbs that you just bought or ones that you just dug up are suitable candidates. Perform this operation by slicing a bulb from top to bottom into 8 or so vertical sections, each with a piece of the base (the "stem").
Yet another way to increase the number of bulblets — especially useful with hyacinths, which are naturally shy multipliers — is with "cuttage." Turn the bulb upside down and score it through its center, dividing the base into 6 pie-shaped sections. Alternatively, scoop out the base with a knife. Either way, you will have nipped out the growing point within, letting side "shoots," i.e. bulblets, grow, just like when you make any stem more bushy by nipping out its top bud.
Plant either the bulb sections, the scored bulb, or the scooped bulb in a large, shallow flowerpot or seed flat and keep the potting soil moist. After a couple of months at room temperature, bulblets can be harvested and replanted.
Lily is a bulb that lacks the papery covering of these other bulbs; a few of a lily's outer scales can be flicked off the mother bulb for rooting. Just take a few so that enough scales are left to nourish the mother bulb when you replant it. Toss the scales into a bag with some moist perlite and keep the bag at room temperature. After 6 to 12 weeks, move the bag into the refrigerator until early spring, when you're ready to plant. Expect three to five bulblets to form at the base of each scale.
When propagating bulbs, just as when propagating any plant, patience is important. The time for your new "bulbs" to reach flowering size depends on the kind of bulb and the method of propagation: a year for a daffodil offset, a couple of years for a crocus cormel or lily scale, three or four years for hyacinth bulblets.
Setting aside a nursery row is the best way to manage digging and keeping track of these plants. Yes, multiplying bulbs does take some trouble and time, but you end up with oodles of plants. And this parenting is fun.