propagating coleus

I posted this to the Coleus forum, but I'm trying this one also. It's a fact that the newer cutting-propagated coleus don't bolt like the old seed-propagated varieties like the Wizard series. That's one reason they are much preferred by growers. Some of them don't produce flowers at all, and some are sterile even if they do bloom a little bit just before cold weather gets them. My question is, what is the scientific explanation of why this is the case? I'm not asking if the phenomenon is true- I'm trying to find an explanation.

Many thanks

James

James, wil try and answer this for you, but not sure if I can fully explain it.

growers are always looking for plants with better qualities than the plants already being marketed, so then the hybridizers get busy tryign to make crosses to met the needs of the growers and the public.

To get these newer qualities the plants are crossed. Usually with coleus it is a hybrid crossing with another hybrid. The problem is when makign alot of these crosses to get prettier flowers, or th ebolting you mentioned, sometimes other qualitie sare lost and usually it is fragrance and ferility that is lost first.

It may be hard to imagine, but some times, just to get one of the new cultivars on th emarket, it is possible that maybe a smany as 10,000 seeds have been grown out and only that one the hybridizers felt worthy of marketing.

When you keep crossing and keep crossing, you may get what yoru looking for , but loose a whole lot more. The reason that thos eplants don't produce seed is becaus e they have been possibly in the begining been crossed with with another plant whose pollen was incompatable, but this one time it took and made the new cultivar, but that plant still carries weak pollen genes or pollen genes that just wil not cros s with any other coleus.

Pollen not only has to be fluffy and viable fo rit to cross with anothe rplant, but it has to be able to make get down the pollen tube that forms and into the chambers of the ovaries. Some pollen is to big to fit, so no chance for seeds. Somepollen takes to long to make a pollen tube and dies before it can get to the ovaries and then again sometimes the pollen will be good but becaus eof so many crosses the ovaries just don't have any eggs left in them is the best way I cna think to explain it and so it makes them sterile.

Now if you have a bloom and alot of time and patience, there are ways to sometimes go ahead and try and get aroudn fertility problems, but it an awful lot of work.

If you want to try and get plants that won't bolt, flower and have some sterile pollen to make seeds, yoru best bet would be to get an old species of coleus and try crossign it with a new one.

One thing that I have noticed too is that with alot of the new cultivars of plants that even if they do make viable pollen the time window that it stays viable is very short. Some pollen is only good for an horu or two, some for days. Also, pollen to be viable for most plants has to fluff itself up, temeprature and humidity play alot in that. Too cold the pollen never fully develops on the anthers. Too hot and it can die instantly.

starlight, Dave's is a great place to be because of the information people like you are willing to share. This is exactly what I was looking for. I hear endlessly that the new cutting-propagated coleus usually don't flower, but never WHY that is the case. I'm a new Texas Master Gardener- or will be certified when I finish my internship soon. I'm getting ready to do up a PowerPoint presentation on coleus, and when I get it done and use it, I want to be prepared in case anyone asks me that question. I have been curious about it for years, but now I have a definite need to know. Thank you SO MUCH.

James, good luck with getting your Master Gardener Degree. Never stop asking asking the question why? The more you ask the mor eyou wil learn and wil be surprised by some of the things you learn.

If you get a chance and have a 4 year college near you, take some of the horticulture classes. You don't necessarily have to go fo r adegree, but can take a course here and there and you will really learn the fasinating world of what makes plants do what they do.

Skip the basic classes and take things like Plant pathology, a greenhouse an dnursery magt class, a tree and shrub class and entomology and insecticide class. Those are some of th ebest classes you can take. You already have the Master Garden class which is like a mini herbacious perennials class, the others will really expand on that learning, you get the meat and potaoes instead of a slice of dessert.

If you don't have the time or unable to take college classes, google things like propagation of coleus, hyrbidization of coleus, use key words for the plants you search and most time sit will bring you to the information about particular plants, what they have been breed for and the trials and what those trials are showing and the hybridizers and their work.

When you think you have your presentation ready, grab a gardenign buddy an dlet them see it and ask all the questions they can think of, your smart, it good to be prepared, you never know what folks will ask. If it should happen that youa question that you can't answer, be honest , tell them you don't know at the moment , but if they will leave their name and a point of contact with you, you will be glad to get back to them.

I have been lucky in getting my degrees and that my mentor had one of the all the time great plant people as his mentor. As you get more and more involved, there is hardly a day and no longer than a week when I am not bugging my mentor or folks here at Daves myself for any scrap of information even as I expand my field and knowledge of plants. We all had to start some place and have been given helping hands to lift us up and help with all the good and bads of the whole plant kingom and beyond. Sharing is the key and I too on many occasions am very grateful for the Dg folks that share their information for problems and questions I myself face.

If ya need more answers, ask away, if I have an answer wil share it with you, if I don't their alot of other people here who will have and will share info in a heart beat too. Good luck with your presentation. : )

There is a whole,detailed explanation in the coleus forum! With photos. Go see!

tommyr, did you read my question? I was not asking how to propagate coleus. It had to do with propagation by seed, but it wasn't a how-to type question.

Tks though for your kindness