I have a good friend who has gotten the rose hybridizing bug. We both have had tremendous success this year with an idea that I simply haven’t heard anyone recommend before. It happened sort of by accident. I had better than average success last year after storing my seeds in the refrigerator in snack baggies containing a thin layer of slightly moist high quality potting soil (I use MetroMix 300 a soil we used at the nursery and greenhouse business I worked at years ago). I suggested my friend try the same method.
As the time came for seeds to begin germinating my friend saw an explosion of germinating seeds. He took the baggies out of the frig and potted those that had germinated up, but never put the baggies back in the frig. Seeds continued sprouting in the baggies on the windowsill. He suggested I try it. I was a little behind him time-wise and had only had a few germinations in the refrigerator. I took the baggies out and did similarly. Pow! Seedlings galore.
Did the high humidity environment in the baggies prove beneficial? I’ve had poor results planting seeds in seed trays even under a good grow light. Has anyone else experienced similar results?
My friend gave me permission to attach photos of some of his seedlings.
[attachment 1690 Natchitoches Noisette x OP.jpg]
[attachment 1693 Fashion Statement x OP.jpg] Fashion Statement is a John Clements intro.
[attachment 1694 Excite x OP.jpg] Excite is a Diann Giles nearly single flo. HT.
After my seedlings begin to slow down in germination rate I will usually take them out of the fridge. This will usually start a new round of germination and certain bags that had poor germination may suddenly decide to grow.
As far as transplanting the sprouted seeds I find that if I can I leave the lights off of them the first day or so. This is not always possible. But I too lose a lot in transplanting. I wonder how many I damage during the process due to uneasy hands.
Your friend has some good looking seedlings.
In 1995 Y. Yambe, K. Takeno, and T. Saito published a paper titled: “Light and Phytochrome Involvement in Rosa multiflora Seed Germination”: in J. Amer. Soc. Hort. Sci. 120,953-955(1995).
The abstract is: " Seed germination percentage of multiflora rose (Rosa multiflora Thunb.) was much higher under continuous white light than in complete darkness. Red light was the most effective in inducing germination, and far-red light was ineffective. Exposure to red light for 1 min increased germination; this effect was saturated at an exposure of 2 min. The red-light effect was reversed by subsequent exposure to far-red light. The results indicate that rose seeds are positively photoblastic, and that the photoreceptor involved is most likely phytochrome."
http://home.roadrunner.com/~kuska/redlight.htm
Hoy127, most everything has been tried by someone. A few folks on this board have tried some similar things, with variations. Many have used peat moss or perlite or clean paper towels Potting mix may be better than peatmoss. Does Metro 360 have added nutrients? Or is it one of the mixes that presume you used a liquid fertilizer? We know that nitrate fertilizer helps germination.
What you are doing is small-scale classical stratification in cold, followed by warm germination, with high humidity maintained. Many people use a set time of 6,8,10, 12 weeks cold, then out to the warm. Your advance is in fine-tuning to the particular cultivar by waiting until things start to pop. In many OP and single crosses, there is a pretty uniform time for most of the seeds to pop, even if kept at a steady refrigerator temperature. Quite commonly 2/3 of all germinations happen within a month or so for a particular cross.
That noisette OP is really interesting. That sure looks like a hulthemia blotch of sorts in the middle. Does the parent show the same pattern?.
That’s generally the method I recommend. (Best viewed with Internet Exporer)
http://www.abrigon.com/hot-roses/presentation/frame.htm
Generally, now I use petri dishes with a layer of soil on the bottom rather than paper towels in baggies, which tend to be higher maintenance because of mold, but the idea is the same. (For beginners, the paper towels allow one to see exactly what is happening, so I like to start people off that way.)