Hello,

I noticed this summer that a fair number (20-25%) of the Daylily blooms would only open up enough to look similar to a tulip. The average high in July when most bloom is 91, the average low is 57. I see Daylilies listed as CMO's, but at what temps should a person really start looking for them? Is mid to high 50's low enough for a fair amount of Daylilies to have trouble opening, or do you think it could just be a trait of those particular plants? The day typically warms up rather quick here.

Thanks,
Gale

I'm not sure I can answer your question exactly, but I have noticed that dl open better in the mornings when they have sunlight shining directly on them.

GDJCB said: Is mid to high 50's low enough for a fair amount of Daylilies to have trouble opening,

It will be interesting to hear what folks say about this.

This past summer was exceptional, in that in July we had few days over 80 or 85, with night lows in the 40ies. So several of my daylilies didn't open fully until about 11:00.

And sorry, Gale, I hit the ThumbsUp button by mistake when intending to pick the quote button ...

Unusually cool summer here as well. Saw more nights in the 50's than we normally see. When nights are that cool I know that some won't open well. Since Richard Norris did work with cmo's, I'm certain he would have the answer to your question.

CMO = Cool Morning Openers?

In addition to cold nights, daylilies seem to resent wide swings between day and night temperatures. Even in the spring and fall, with nights in the low-mid 50's, they open fairly reliably, which I suspect is because the days are moderate as well. Naturally, much of the "fanciness"—fringing, patterns, eyezones—is muted, but they at least open correctly, and the colors are rich.

The real problem daylilies have here on the west coast seems to be the type of evening they have, rather than the overnight low. The temperatures tend to fall below 60 soon after sunset, and then every type of difficult opening can be seen the next day. Forty miles inland, it might still be 75 degrees at midnight, followed by a slow decline to 60-65 by morning. This gives the bud plenty of time to develop fully in preparation for bloom, and the flowers have more of a normal appearance.

Ken
East S.F. Bay Area
USDA Zone 9

Thanks, every one for your input. I would still be curious to know, under what conditions would CMO's be a trait to key on, when looking for Daylilies. Is it just a certain low temp, length of time for a certain temp, timing of temps, etc? I have been looking at adding more Emmerich and Norris plants with an eye towards instant rebloom. I also have noticed CMO and EMO in the description of some plants and was wondering if I should be adding that trait to the need list, for the plants I purchase. Thanks again for the info you have shared.

Gale