Tuesday, January 8, 2013

The difference 2 months can make in bloom percentage

Dan Robarts asked me to show pics of the GH a year ago on today's date (first picture - where the seeds were planted Jun 1, 2011) compared to today (second picture - where the seeds were planted August 1, 2012). You can see that the pictures are taken in the identical location.Although some of the difference in the size of the plants in these pictures is because this year's crop in these particular beds has more dormants than last year's (including kids from Alpha and Omega, patterned 26712 which is out of dormant 52708, etc.) you can see the huge difference in size (note where the top of the plants are vs the top of the green marker flags) - which is the reason I got a large percentage of first year bloom last spring and why it will be much lower this year. Unfortunately, the only way to be able to plant June 1 is to use have empty beds to plant in and to use seeds made in the previous year rather than the current year. Looking at the second picture is kind of depressing, except when I remember that that is what all my pictures have looked like in early January except for last year, so there should still be a lot of bloom in April and May.

Note: you can see in the bottom picture that the bed by the wall is empty. I decided to plant fewer seeds (3000) than usual (5500) this year because of the national convention and all the work entailed in stripping out the greenhouse. That bed always has a lower percentage of bloom than elsewhere in the greenhouse. Even though that wall faces south, it shades the plants during times of the year when the sun is very low in the sky - a dumb design error on my part. I was advised to put in a short insulated wall (about 3' high) on 3 sides and a full insulated wall on the north side to save on energy. Because most people with greenhouses grow their plants in pots or trays on 3' benches it never occurred to the builders to advise me that a south wall might be a problem. In fact, one builder recommended 5 foot walls on those 3 sides to save on energy. Fortunately, I decided against that because I wanted to be able to look outside while I was working - ouch, that would have been a disaster! and very expensive to correct. For those of you who want to get into the weeds, the east side also has a large garage door that blocks some of the light, but the seedlings in the east third of the greenhouse have the highest percentage bloom rate because they get more hours of sunlight during the day than anywhere else. It is also dryer on the east end (and warmer soil because of more sun) and more spider mites because of that!


  1. Hi Karol,

    I have been reading some of the points you've made about growing seedlings. I agree with you that the amount of "sunlight" makes a big difference. Last year I believe that we had less sunlight, and so I had to plant many of my seedlings outside so that I could see their first blooms this coming spring. Then, with dormants, I just can't get them to bloom in one season.

    I'm finding that the more that I use conversions the more I create dormants. The dormants are tough, but for the most part they do not multiply as fast as I would like. Still, dormants are to be preferred especially in climates that have real winters.


  2. Yes, it is the rare dormant that blooms the first year. They seem to multiply fine outside, but poorly inside. FYI, I would say that about 10 percent or so of my seedlings are dormant, but about 50 percent of my intros are. A conundrum.

  3. Thanks for posting this, Karol. I think this is very interesting and important to realize how critical early planting is for decreasing time to bloom on new seedlings. Am exited to see what your upcoming post will be on parent plants!