Lilies Thrive This Easter, Thanks to Find of UMass Amherst Researcher

AMHERST, Mass. - University of Massachusetts plant researcher and associate professor Susan Han discovered something several years ago that Easter-lily lovers will appreciate over the next few weeks. After experimenting with a variety of remedies for a condition that attacks the holiday lilies, Han tried a growth hormone readily available as a nursery product and sprayed it on the tall, leafy plants. This simple procedure, she said, protected the lilies from foliar chlorosis, the bane of the greenhouse industry''s third most important product.

This is the first Easter season that many commercial growers will benefit from her research, partly because it is included in this year''s growing guide published by Fred C. Gloeckner Co., of Harrison, N.Y., one of the nation''s biggest Easter lily bulb suppliers. When millions of the white trumpet flowers bloom next week across the U.S., Han will know her research in the UMass department of plant and soil science paid off.

Commercial Easter lily bulbs need three to four years in the field before they are harvested and forced in the greenhouse for seasonal blooms. When Easter falls late in spring, as it does this year, the lily crop ties up valuable greenhouse space late in the spring that growers could use to prepare bedding plants for gardeners. If lilies are ready to bloom too early, growers put the potted plants in cold storage until it''s time to ship them.

Cold-stored lily plants can develop foliar chlorosis, a condition that produces unsightly yellow leaves, leaf drop, skimpy blooms, and, ultimately, premature deterioration of the entire plant. "A consumer would buy a plant just before Easter with beautiful leaves, lots of buds, and three days later, boom, it''s all yellow," explains Han.

Florists often wrapped the plant stems in foil or ribbon to hide the condition, but, until now, they could not hold back the progress of the disorder once it began. Now they can. Han found the spray stops foliar chlorosis dead in its tracks, without harming the plant or people. "The combination of spraying and cold storage gives the commercial grower more flexibility in scheduling the lily crop. The spray protects the plant from more deterioration, and it gives consumers a quality plant to enjoy for a long time."

Potted Easter lilies rank slightly behind poinsettias and geraniums in dollar value to the greenhouse industry. In Massachusetts, their annual wholesale value is estimated at $1.5 million, according to Han.

Susan Han has a collection of healthy Easter lilies in her greenhouse laboratory for video or photo purposes. She can be reached at 413/545-5228 or susanh@umext.umass.edu.