Hi everyone,
I have a couple of very basic questions about HT/floribunda seedlings at the first bloom stage. Space is scarce, and I’d like to be able to cull as early as possible, but I don’t want to throw seedlings out too quickly either.
Petal count: I remember seeing a brief interview of Fabien Ducher where he mentioned that some seedlings’ first blooms can have only five or six petals, and then as the plant grows the petal count can go up by a lot.
He didn’t go into detail and it wasn’t clear to me if that is something that can happen or if it’s frequent? Assuming both parents are double/very double HT or floribunda types.
What about other characteristics?
Is health also something that can improve? Can seedlings with early mildew vulnerability become more resistant as they mature?
What about fragrance? Is it there from the first bloom or can a seedling which is at first unscented develop fragrance later?
Petal count can increase, sometimes dramatically, with maturity. Not always, but sometimes. Health is another matter. I’ve found the more diseased seedlings often don’t have vigorous root systems under them. They may have pretty color, form and even scent but lack the vigorous root system. That may improve with maturity, but it seems from my experience that it is highly indicative of whether that seedling will root well and grow well own root. They may well perform beautifully budded to better roots but do you really want to produce more of those? Personally, I think we’ve had far more weak growers (often with bad health) requiring budding than we should have. The first thing I look for when culling is weak root system. If they won’t produce a good foundation under them, they’re gone. Unless they represent a difficult and unusual cross I’ve attempted repeatedly and are the limited success from it. Then, I’ll grow them a while and perhaps even bud them because of what they represent. (Such as species crosses which haven’t enjoyed much success) Scent can increase, but in my experience, not tremendously. If a seedling smells, the mature plant will smell. If it doesn’t, rarely is it going to develop a great scent as it ages. I go for the weak root system first. It usually goes hand in hand with bad health, so eliminating one often takes care of much of the other.
I’m not an extreme HT/Floribunda expert, but maybe my experience can still give you a little reference anyway.
Petal count: Seedlings with five or six petals at the first flowering will mostly become max. semidouble.
Health could be improved. Some seedlings need a little more time to develop. The second year could be decisive in this case.
It depends on the strength of the disease and the constitution of the root system of the seedling. If the fungal infection is very strong, the seedling will get too weakened for further development. In this case, further cultivation is usually not worthwhile. With very weak expressions, it could be worth giving the plant a chance. With rare seedlings, I have had the experience several times that the susceptibility had completely disappeared in the second year and stayed that way. Of course, other external influences also play a role.
Fragrance: I never had a seedling which was unscented with a later developping remarkable scent.
Thank you both very much!
That is extremely helpful information, I really appreciate your replies. @roseseek , I will pay close attention to the root systems and eliminate the ones that don’t have well-developed roots.That’s going to be a very used criteria, especially since budding isn’t something I plan on learning how to do in the foreseeable future, since that would take up yet more space. @Roseus , thank you for sharing your experience regarding disease resistance possibly improving in the second year. I guess then, if there’s only a little bit of mildew I should allow more time to evaluate that aspect IF the roots are strong.
You both seem to agree on fragrance not improving if first blooms are unscented. I couldn’t find that information anywhere and it will spare me a lot of false hopes. Thank you!
You’re welcome! I totally understand the room issue. Budding, though, really is something you should learn. It’s a very fast, easy way to quickly replicate desirable seedlings. Ralph Moore used to bud them as standards simply to see what the plant architecture would be. Standards are also nice plants to enjoy in the garden.
You’re right roseseek, I guess I could try it next year.
In my boyfriend’s garden there’s a large “Laxa” rootstock that must have overtaken whatever rose was grafted onto it a decade ago, judging by the many trunks’ size. Perhaps I could try rooting a few cuttings of that and practice budding onto them next year just to get the hang of it. It also has a bunch of hips still hanging on from last year’s blooms, so I could try growing those from seed, but that would probably take even longer until I get something I could use for budding.
I know you can also just order bare root Laxa for grafting, but those tend to be sold in large bulks.
Either way, my current seedlings will have to manage on their own roots for now ! Thanks again for your kind advice.
With pleasure! I absolutely agree with @roseseek and would also like to recommend you to use the bud grafting method. It is a really useful technique to follow the developmental steps faster and thus to see more quickly if the seedling has the desired characteristics or not. In addition, rare crosses and thus particularly more interesting offspring, which are a little more delicate in habitus, often get a valuable boost. A direct comparison between original seedling and replica is possible and the selection can be done more efficiently.
Thank you Roseus. I will try it out next year!
Bear in mind, I have only just learned even basic things like rooting rose cuttings last year. The seedlings that are growing here now will be my first ever from crosses I made. This year I am trying to do better thought-out crosses, and trying my hand at freezing pollen properly and embryo extraction (two skills that don’t take up space). I have so many things to learn!
Petal count. The 5-petaled ones mostly do not add up (much) with maturity. The more petals you get, the more is the chance they can add up. Depends also what you want. There are also very pretty roses with low petal numbers, which is good for bees, too. For myself, the petal number is a less important feature in comparison to the…
…Health. There are many facors here. One of them is that the young seedlings may not have conditions which are good enough for full development (due to the lack of space, maybe); they may be too close to one another, too little aeration etc. Once they get their own space, separate pot (or spot), more air, more light, they can improve. Another factor is the root system, exactly like mentioned here before. If a seedling does not develop a robust root, it will fade and eventually die. So this is a very important thing. Once you see a taller and strikingly well developed seedling among the rest of them, you have a good eye on it. It might be a keeper. Then, there is another thing - grafting. There are roses which can not grow well on their own root, but do very well when grafted. It can also improve resistance to fungi. So, if there is a seedling which is good in any other aspect, except for a ‘not such a good’ growth, it can be grafted and tested further.
Fragrance. Usually a fragrange is present from the very beginning. But, returning to petal number, and, as we know, that the fragrance oils are coming from the petals, with the growing petal number in maturity, the strength of the fragrance may certainly increase. There are other factors there as well, f. i. the temperatures and humidity which can influence the fragrance. Some of my seedlings which did not smell too intense at room temperatures, suddenly developed a strong scent when I put them outdoors at colder temperatures and returned them indoors for the night. After I took them indoors, they had a strikingly strong scent. So, briefly, these are the things to consider.
Thank you @Giessen ! I really appreciate your detailed reply. I agree single flowers can be just as beautiful, and in some cases it can actually be better not to have too many petals. I am just trying to know what to expect once that first bloom shows up, and your comment is very helpful!
I am potting up some of this year’s babies these days and definitely noticing rapid growth and improvement in many of them as soon as I get them into bigger pots. The introduction of real sunshine and breeze as I start to bring them outside also makes a big difference versus my (probably insufficient) lamps.
I am learning from you and the others here the importance of the root system in this whole process. Might sound silly, but I used to think such tiny plants must be fine in tiny pots, so this is a mistake I am in the process of correcting.
Tiny plants in tiny pots sounds “cute” and perhaps even desirable, however, the smaller the pot, the faster it literally cooks in direct sun, hot air and winds. “Silly”? No. Perhaps inexperienced. If you’re growing the tiny pots in controlled conditions and are able to police them daily (perhaps even more frequently during extreme conditions), or WANT to police them constantly, then tiny pots may be enjoyable but who has time and the desire to take that on? It’s like having small children or an ailing person relying on you.
Well, I use 4x5 cm pots for seedlings, but they are positioned indoors in trays under strong plant lights and I check/water them on daily basis: they are in strongly controlled conditions. Once they have their first bloom (usually this happens in 1—2 months after germination), I make my first selection (based not only on bloom, but on vigor, too). The keepers are replanted in bigger pots (3—5 L) and moved either to the greenhouse, or outdoors, if the current weather conditions allow that. The rest is immediately culled and goes to the bin. Since the seedlings germinate not all at the same time, the process of planting and replanting lasts from february to midsummer. This allows me to handle many seedling in total, but with attention to every single one. The first seedlings start to germinate in january; in february—march they bloom and either get culled or are kept and replanted/moved. I check for new germinations every 7—10 days (stratification is done in the fridge). In 2021 I had 142 hand pollinations, they resulted in 1200 achenes and 453 germinations, 171 of them bloomed and 48 of those were selected for further observations and replanted in bigger pots. There were some once–bloomers in my total yield of achenes as well (where I crossed once–bloomers and did not expect a bloom for the first year), so for those I had different selection criteria and replanted them too, as soon as the preselection took place. But considering a relatively large number of germinations — 453 (well, sure, some breeders can have millions of seedlings, but I am not that type yet…), I could not manage them all simultaneously due to the lack of space (or plant lights, space in greenhouse, etc)… So the whole process takes months in my case, and this is good for me. The procedure depends very much on what resources you can provide; you can use any pots or any supplemental materials which work well for you and for your own established protocol.
I started to use lamps also because from january/february the light outside is very low. I tested with LUX meter and i am at 15K when the lamp is close to the seedlings. But in the sun now it reaches 50K+ LUX and the bigger seedlings starting to make blooms a lot faster. I use the lamp as a secure startingpoint when they just sprouted.
I am curious which lamps people use. I am using 7 * 30 W full spectrum (40 LED) lamps. Do you see a differance in blooms develope under your lights and sunlight?
Wow, TimoNL those lamps look really cool!
Mine are just some very basic growlights from Amazon, and another by a brand called Garland. I really need to step up my game! I just measured and the max I am getting from them is about 10,000 lux haha… No wonder they enjoyed getting out into some real sunlight so much!
Some fragrance types seem to evaporate quickly, like cloves. For the longest time I thought everyone online was lying about Dagmar Hastrup having a strong fragrance, it never did when I sniffed…then early one morning, there it was, cloves. Similar thing with Ebb Tide, I could smell the citrus in it all day but never the cloves, was just smelling it at the wrong time of day. I have a ~1yr old seedling, that I thought was scentless until recently, it’s just cloves (no other notes, no citrus, no florals) it stinks.
Not really an issue with the more usual scents, but some of them really like to hide unless you’re sniff testing multiple times a day.
another example…Cardinal Hume, still haven’t found the cinnamon scent in that.
TimoNL or SeasideRooftop, have either of you ever calculated the Daily Light Integral that you provide to your seedlings? With my light source, distance and hours per day, I’m around 12 -15 DLI, and that isn’t the greatest, but enough until I can transplant outdoors
Nice. What app is that? I’ve been doing my calculations with a pencil and paper
I normally only use artificial light 12-15 hours/day, just because I assume there are benefits to mimicking normal sunlight cycles.
