“I would like to grow some paperwhites for winter interest this year and need some tips on how to be successful.”
— Jerome Baker, Chicago
Paperwhites are normally easy to grow indoors, and most people buy them to provide flowers in winter, as you intend to do. They do not need much space, so plant them in tight clumps that are almost touching, in either a potting medium or pebbles — I prefer using a potting medium.
The potting medium should be for container plants and needs to provide support for the plants and be suitable for roots to grow through. Install the bulbs so that the top of the bulb is level with or about an inch or so above the top of the growing medium.
Although paperwhites do not require a period of cold and darkness to bloom, it is still a good idea to start them in a cool, dark location and transition them to bright light over a couple of days as the bulbs sprout. The foliage may burn if moved directly to bright light from the darkness, and the plants do not like to be overwatered.
If planted in pebbles, add enough water to be just below or at the base of the bulb to encourage root growth. This is difficult to do if you cannot see though the sides of your container. Drop the water level as the roots develop to avoid rotting the bulbs. There is no need to fertilize the bulbs.
Paperwhite bulbs can develop basal rot, which is caused by the fungus Fusarium during shipping or storage. To reduce the possibility of encountering problems from basal rot, purchase bulbs that are free of blemishes, pale in color and firm to the touch. If you encounter bulbs that are brown and mushy, rather than firm and white, the bulbs likely have basal rot and should be discarded.
Paperwhite bulbs can rot once planted if given too much water. When gardeners grow paperwhites in gravel with standing water, the roots need to maintain contact with water, but the bulb should not. Letting the bulb sit in standing water can lead to rot. It is important to maintain the water level so only the roots are wet, topping off the water level daily if necessary.
The new growth of paperwhites can become very leggy and flop over when grown in temperatures greater than 65 degrees Fahrenheit. Since most homes are kept warmer, leggy plants that require support are a common issue. They will also be spindly if grown without enough sun, so they should be kept in bright light.
For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at [email protected]. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.