Forcing Paperwhites Indoors

One of the fastest ways to get indoors flowers in the winter—even easier than African violets on the windowsill—is by growing certain flowering bulbs in either potting soil or vases of water.  

The easiest bulbs to get to flower indoors – called “forcing” – include amaryllis, fragrant hyacinth, grape hyacinth (Muscari), and members of the Narcissus tazetta group, commonly called “paperwhites.” Forcing isn’t a cruel thing, it just means getting them to grow roots, shoots, and flowering stems indoors out of season.  

Fast, Easy Paperwhites

Paperwhites are very easy to force in either moist potting soil or water. The water trick is the simplest: Stick bulbs part-ways into clean gravel, glass beads, or other loose material in which roots will grow and intertwine to support the top-heavy growing plants so they don’t tip over. I have even used colorful Mardi Gras beads!

Then add just enough water to touch the base of the bulbs, not much higher or you might rot them. Check every few days to replace whatever is used by the bulbs or evaporates in the dryness of indoors. Within a few days or a week you should have strong white roots showing, and within three or four weeks you should have beautiful, fragrant flowers. 

The Famous Alcohol Trick

Most people who force daffodils indoors notice that they usually get tall in the low light of indoors and flop over under the weight of their flower clusters. There is a fun horticultural trick to prevent this: Adding just a little alcohol to the water you use with the bulbs. The flowers will bloom at the same time with the same size and fragrance as non-treated ones, but they will have much shorter, sturdier stems. 

This was discovered by bulb researcher William Miller of Cornell University, who found that, to a point, the higher the alcohol concentration, the shorter the plants will grow. He recommends using only about five percent alcohol to water. This means adding one part isopropyl alcohol (rubbing alcohol) to ten parts water, or one part clear “hard liquor” (typically 40% distilled spirit) such as gin or vodka to seven parts water. Remember, too much alcohol can kill the bulbs, so stick with these ratios to water.

Start the bulbs out with plain water until roots appear, then pour that off and start using the alcohol/water mix. The bulbs should flower within three or four weeks on short, sturdy stems. 

Stick With the Easy Ones

There are a couple of reasons why other bulbs, including tulips, colchicums, and some hyacinths, fail to flower indoors. When selecting bulbs for forcing, look specifically for recommended varieties. And keep in mind that some take several weeks of “pre-chilling” in the ‘fridge to jump-start their flowers; avoid this by refrigerating all but paperwhite bulbs for a month or so before planting. 

On top of this, some bulbs are actually damaged by fruits stored nearby; fruits give off a “ripening gas” called ethylene, which can damage or even kill the flower buds in bulbs. Best to keep them separate. 

Kiss ‘Em Goodbye

Most gardeners, being thrifty sorts, hate to throw out a perfectly good plant even when it is way past gone. But when paperwhites are forced in water, they get totally spent, with little or no chance of their surviving later in the garden. Best to head to the compost with them.