Eucomis Lily: Opportunity or Flash-in-the-Pan for Zone 5 Grower
The regal columns of the pineapple lily flowers (Eucomis) are impressive, and a vase life of nearly a month confirms that impression. Interest in this flower seems justified for milder regions, in which the crop can be grown as a perennial in the field, but does it make sense in the cooler parts, where winter survival is trickier? Our experience with Eucomis in Ithaca, New York (Zone 5b) may help answer this question.
The pineapple lily originated in the Drachenfels Mountains of South Africa, and has been selected and improved by plant breeders in New Zealand and other locations to produce stems long enough for cut flowers. They are classed for winter hardiness zone 7, but since the overwintering structure is a bulb, surface mulching can improve its chances of survival. We found that potted plants transplanted to the field in early September 2013, survived only if mulched with 2 inches of wood chips, compared to being placed in unmulched bare soil. At another site near campus, a mulch-covered Eucomis planting continues to thrive after two winters.
A more reliable way to keep them alive in Zone 5 is to grow them in a high tunnel (unheated, clear-plastic covered greenhouse). Our oldest plantings of Eucomis are now three years old, and have grown vigorously over that period. However, fewer than half the bulbs planted originally (from commercial sources) produced flowers in the first year. Yields and stem length have increased each season (see table), but the planting is now so crowded that we worry about continued productivity. The crowding comes from the fact that the original mother bulbs have produced a ring of tightly-attached daughter bulbs, each of which has its own set of leaves. This thicket of leaves collapsed by mid-August this year, and may reduce the ability to resupply nutrients to the overwintering bulb. We will deliberately leave one very crowded planting until next year, to determine detrimental effects.
Another consideration for the Eucomis crop is its very concentrated flowering period. Our tunnel crops were harvested in 9 to 14 days in the 2013 and 2014 harvest seasons, a prohibitively short marketing period, especially for a crop largely unknown by the general public. Field-grown Eucomis crops lengthen the market window by flowering a month after the tunnel crop, so having both would seem like a good strategy.
These uncertainties about winter hardiness, plant spacing needed for long-term productivity, and a short market window may slow adoption of the pineapple lily as a cut flower crop in Zone 5. It may thus be wise to try Eucomis on a small scale initially.
Table. Yield and stem length of four pineapple lily varieties planted in a high tunnel in April 2012 at 12 x 12 in. spacing.