Dierama won't flower

Discussion in 'HortForum' started by Daniel Otis, Dec 30, 2011.

  1. Daniel Otis

    Daniel Otis Active Member Maple Society 10 Years

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    Hi all. I grew a Dierama pulcherrimum from seed a long time ago--at least 15 years, maybe closer to 20. Ever since, I've grown it in a pot, because I'm in zone 6 and I doubt it would survive in the ground. I keep it outside during the summer and bring it into a cold basement (30s) or a warmish (50s) basement for the winter. But after all this time, it has never flowered.

    I've been patient. The plant seems to flourish--it has many leaves and has filled a 5-gallon pot. I repotted it once, a few years ago, and discovered long chains of small bulbs--perhaps 6 or 7, each representing a new year's growth, I think. There were lots of these bulb chains--dozens. In recent years, I've fed it rather heavily; during some earlier years, though, I didn't fed it at all. Nothing seems to work. I haven't been able to find out much about this, although I have seen references to others having trouble flowering it in a pot. Could the problem be that the soil temp is too high?

    Does anyone have any ideas? I'd love to see some flowers at least a few times before more decades have passed.

    Thanks.
     
  2. johnnyjumpup

    johnnyjumpup Active Member

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    I hope someone can answer Daniel's question. I got my hands on some dierama bulbs after coveting them for years. I too put them in a pot and got only leaves for three or four years before they got lost in a repotting frenzy. I'd like to try again.
     
  3. Eric La Fountaine

    Eric La Fountaine Contributor Forums Moderator 10 Years

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    I successfully grew Dierama years ago when I lived in Seattle. I have had them in the ground in Sechelt for at least 8 years and planted more there a few times. I get green leaves, but have had only a few poor flowers. I asked Brent Hine, who curates the E.H. Lohbrunner Alpine Garden here, what the problem might be. He said he has a hard time getting enough water to them in the summer. (They do bloom very well here.) I always watered my garden in the summer in Seattle, but Sechelt is a getaway cottage and does not get tended carefully, so gets very little supplemental water in summer.

    Dieramas want the opposite climate to ours. They want steady moisture in summer and drier conditions in winter. You can grow them in pots and protect the pots from cold and excessive wet in winter. Unlike some other Iridaceae they will not tolerate having their corms dug and stored for the winter.

    I am going to add some compost to my plants in Sechelt and see if I can get more water to them next summer.
     
  4. Daniel Otis

    Daniel Otis Active Member Maple Society 10 Years

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    Thanks for giving us the benefit of your experience--and to JohnnyJ for seconding the question.

    Because I grow my plants in pots, they get watered nearly every day in summer, but because on some level I've ceased to expect them to flower maybe I should be more diligent. In winter I keep them under cover at about 50 degrees F, and they stay quite dry. I've been reluctant to repot them because they are said to resent it, so maybe the soil has gotten rather thin.

    I wonder if, like some other bulbous (or cormous) plants, they tend to produce only foliage if the bulb isn't buried deeply enough. I may also try planting them in the garden somewhere where I can bury them under three or four feet of leaves over winter (along with some agapanthus), so the ground will never get too cold. I've never actually seen them in flower--just photos. I'll keep trying--will perhaps split them into several pots so I can try different approaches. A lifelong garden challenge.

    Are they ordinarily evergreen, or do they tend to lose the previous season's leaves over the winter?

    Again, thanks.

    D.
     
  5. Eric La Fountaine

    Eric La Fountaine Contributor Forums Moderator 10 Years

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    I am not sure how much of the leaf is lost or how long they last. The plants have green leaves in winter, but seem diminished compared to the summer foliage. I have not really been paying that much attention to my plants and only tend to notice the ones here at UBCBG when they are blooming. There are quite a few species-several grow at the Garden, so I am sure there is a lot of variation. We are Zone 8. I am sure it would be much harder to grow them in NY.
     

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