How Do You Grow Paperwhites Indoors Without Them Flopping Over?

Grow paperwhites in a shallow bowl of stones with water just touching the base of the bulbs, give them two to three cool, dark weeks to root, then move them to a sunny window. Iowa State University Extension recommends 45 to 50 degrees for the rooting stage and 60 to 70 degrees once the shoots are 3 inches tall. UF/IFAS, the University of Florida's extension service, says full flowering takes about 4 to 8 weeks from planting.

The flopping has a tested fix. Cornell University's Flower Bulb Research Program found that watering paperwhites with a 4 to 6 percent alcohol solution, mixed as one part 80-proof liquor to seven parts water, stunted the stems and leaves by 30 to 50 percent while the flowers stayed as large, fragrant and long-lasting as usual. Stronger is not better, because solutions above 10 percent alcohol were toxic to the plants. This post covers planting in stones or soil, how long the bulbs take, why they fall over, how to use the Cornell method, and which varieties have a lighter scent.

What are paperwhites?

Paperwhites are a type of narcissus, Narcissus tazetta, grown indoors in winter for their clusters of small, fragrant white flowers. They are relatives of the daffodil.

What sets them apart from other forced bulbs is that they skip the cold treatment. The University of Connecticut's Home and Garden Education Center notes that all hardy bulbs must be chilled at 35 to 50 degrees before forcing, except for paperwhite narcissus. A paperwhite bulb is ready to grow the day it comes home.

How do you plant paperwhites? 

Paperwhites grow in water and stones or in potting soil. Iowa State University Extension gives directions for both.

In stones and water

Use a clear, shallow bowl with no drainage holes. Partially fill it with washed gravel or stones, set the bulbs on top, and add more stones around them, leaving the tips of the bulbs exposed. Add water until it touches the bottom of the bulbs, and keep it at that level for the whole forcing period.

The water line is the detail to watch: touching the bottom of the bulbs and no higher.

In potting soil

Partially fill a pot with potting soil, set the bulbs on the surface, and add more soil so the tips stick out above it. Iowa State recommends leaving the soil level half an inch to an inch below the rim, watering thoroughly after planting, and keeping the soil moist throughout. 

How long do paperwhites take to bloom?

UF/IFAS gives a range of about 4 to 8 weeks from planting to full flower. Iowa State University Extension breaks the early part into two stages: 

• Two to three weeks in a cool, dark location at 45 to 50 degrees, to encourage root growth
• A move to a sunny window at 60 to 70 degrees once the shoots are 3 inches tall

For flowers around December 25, the 4 to 8 week range points to planting between about October 30 and November 27. Starting a second bowl two weeks after the first stretches the show.

Once the flowers open, Iowa State suggests moving the bowl out of direct sunlight to prolong the bloom period. 

Why do paperwhites flop over?

Paperwhites flop because the stems grow tall and soft. UF/IFAS describes flower stems of 12 to 18 inches and explains that plants grown somewhere too warm or with too little light may produce leaves and flower stalks that grow too tall and fall over.

That points to two fixes that cost nothing: 

• Give them the sunniest window in the house once they come out of the dark.
• Keep them cool. UF/IFAS recommends a sunny, cool location to help prevent flopping, and Iowa State's range for this stage is 60 to 70 degrees.

The Cornell method below goes a step further and shortens the stems themselves.

Does alcohol really keep paperwhites short?

Yes. William Miller, professor of horticulture and director of Cornell's Flower Bulb Research Program, tested the idea after a reader told The New York Times that gin had kept paperwhites from growing tall and floppy. Miller and a student, Erin Finan, ran trials on the variety 'Ziva' and published the results in the journal HortTechnology in April 2006.

According to Cornell's report on the study, properly treated paperwhites were stunted by 30 to 50 percent, and their flowers were as large, fragrant and long-lasting as usual. Solutions of 4 to 6 percent alcohol did the job. Solutions above 10 percent were toxic.

Cornell's directions are simple:

• Start the bulbs in plain water.
• Wait until the shoots are several inches long.
• Pour off the water and replace it with a 4 to 6 percent alcohol solution.

To make a 5 percent solution from 80-proof liquor, which is 40 percent alcohol, mix one part liquor with seven parts water. Gin, vodka, whiskey, rum and tequila all work. Rubbing alcohol at 70 percent is diluted further, one part to 10 or 11 parts water.

Skip beer and wine. Cornell notes that their sugars harm the plants.

The reason the trick works is still an open question. Miller's best explanation was water stress: the alcohol makes it slightly harder for the plant to take up water, enough to reduce leaf and stem growth without affecting the flowers.

Do all paperwhites smell strong?

No, and this is worth knowing before buying. UF/IFAS describes paperwhite flowers as extremely fragrant, with a sweet scent that can fill a room. Some people love it and some find it heavy.

Variety makes a difference. 'Ziva' is the traditional paperwhite and the one Cornell used in its trials. Roots to Petals notes that the 'Wintersun' and 'Nir' paperwhites it uses in its hydroponic paperwhite gardens have a much lighter and more pleasant scent than traditional 'Ziva'. Anyone who has given up on paperwhites because of the smell should ask for the variety by name.

What do you do with paperwhites after they bloom?

Compost them. Iowa State University Extension states that paperwhite bulbs should be discarded after flowering, that they cannot be forced again, and that they are not hardy outdoors.

Keep the bowl away from pets while it is on display. Paperwhites are listed with daffodils and other narcissus on the ASPCA's list of plants toxic to cats.

FAQ

Do paperwhite bulbs need to be chilled first? 

No. Paperwhites are the exception among hardy bulbs and can be planted without a cold period.

How much alcohol do you add to paperwhite water?

Mix one part 80-proof liquor with seven parts water for a solution of about 5 percent alcohol. Cornell found 4 to 6 percent effective and anything above 10 percent toxic to the plants.

When do you start using the alcohol solution?

Wait until the shoots are several inches long, then pour off the plain water and replace it with the diluted alcohol. 

Can you use rubbing alcohol on paperwhites?

Yes. Cornell's directions call for diluting 70 percent rubbing alcohol at one part to 10 or 11 parts water.

Can paperwhites be planted outside in Pittsburgh after they bloom?

Iowa State University Extension says paperwhites are not hardy outdoors and should be discarded after flowering.

How tall do paperwhites get? 

UF/IFAS lists flower stems of 12 to 18 inches. Cornell's alcohol method shortens the stems and leaves by roughly a third to a half. 

Are paperwhites toxic to cats? 

Yes. The ASPCA lists paperwhites under narcissus on its list of plants toxic to cats.

Paperwhite and Amaryllis Gardens at Roots to Petals

Roots to Petals is an independent, woman-owned florist and plant studio at 527 Allegheny Avenue in Oakmont. Its winter bulb gardens include a hydroponic paperwhite garden made with three jumbo bulbs set over leca in a glass vase, along with amaryllis gardens. The Plant Studio carries houseplants and pottery year-round. For more reading, see the shop's posts on the best house plants for Pittsburgh homes and apartments, on flowers to plant in the fall in Oakmont, and on where to find flowers, plants and workshops in Pittsburgh.

Visit Roots to Petals or call 412-822-6023 today. Contact us for more information.