A close friend and I are experiencing very poor, almost non existent, germination rates for seeds that we pollinated. We have great germination rates of op hips from public gardens. Right now I have well over 200 seedlings germinating under lights and only one is from a cross that I made. Are crosses set hips and a fair percentage stay on the bush for later collection. Both of us fertilize our roses weekly. Mine get a 1/4 teaspoon per gal. of 20–20-20 weekly, and once a month they get fish emulsion, sprint, and epsoms salt. Also whenever I have time they get some Alfalfa about quartely. The plants look terrific during the growing season. I’m not sure what my friend uses but he is a constant winner at our local rose shows.
My seed parents are proven seed parents; Fairhop, Loving Touch, Sequoia Gold, June Laver, etc. Same for my pollen parents; Kristin, Signature, Pristine, Sachet, etc.
I did about 70 crosses and Jim did over 200. On various posts here I have read that fertilizing seed bearing roses
can cause problems with germination rates and I have also read here that fetilizing your plants does not have any impact on your germination rates. Have there been any studies done on this subject. What do you all think is going on with our viable seed production.
Stay warm, it’s now 11 degree’s in Argyle, Texas
Thanks,
Bill Cashin
North Texas
Bill,
Did all of the seeds receive exactly the same stratification treatment?
How old are the plants you are using as seed bearers? Often, young plants (under 2 years old) do not reliably set seed.
I am one of those people who believes that seed bearing plants should be grown lean and mean. Mine get a tablespoon of Osmocote at the beginning of the season and maybe one water soluble fertilizer application in July or August, but otherwise its just water. I am certain that regular feeding can interfere with formation of seeds. A well fed plant is a lazy plant, IMO. Plants that are moderately stressed are going to be far more motivated to produce seed; its about survival.
You don’t mention anything about your growing conditions: are your plants grown in pots? Under lights? Out in an open bed? What chemicals do you apply for disease control? Did your crosses stay on the plants until the hips turned color? Did your plants get exposed to any freeze events? Is there any difference at all in how your seeds and the collected OP seeds were treated? How long have your seeds been planted? (I assume you have planted directly in soil. I do not allow germination in the fridge because I find seedlings germinated in flats fare much better and have a higher survival rate)
About the cultivars you have selected: ‘Sequoia Gold’ rarely produced viable seed in the first two years I grew it. Year three the seeds started germinating fairly well. Year four and I got so many seeds and nearly every one germinated, I could barely cope with them all. ‘June Laver’ always has a low germination rate for me. Usually it gives less than 10% germination, which is why I no longer use it, except in experimental crosses occasionally. ‘Loving Touch’ usually germinates like weed seeds, but again, the plant had to be three years old before it became a reliable seed setter.
One other very important thing: don’t prune seed bearing plants like you would prune normally! Plants that get pruned as you would for garden display or cut flower production will not make good seed setters. Ralph Moore told me repeatedly that he rarely pruned his seed producers, and if he did it was just to trim back spent bloom stalks and trim the plant’s outline a wee bit. I never remove more than an inch or two of growth, barely trimming the canopy of the plant. Personally, I think this is very important and affects seed production considerably.
The only other thing I can say is that it is a given that open pollinated seeds often germinate better than our planned crosses. Still, what you describe sounds unusually poor. I’d lay off the fertilizer after one or two light feedings at the very start of the year. Maybe you should avoid feeding at all and see how it goes. And don’t prune back your plants except to tidy up ends of branches!
Best of luck,
Paul B.
Thanks for your input Paul.
My miniature seed bearing plants are growing in 10 to 14 inch pots outside and most were about 2 years old last year. So that appears to be part of the answer
Since I grow primarily to produce cut flowers I prune them very heavily. I will follow your puning instructions this Spring.
All of my seeds were placed in plastic zip lock bags with some spagnum peat moss moist but now wet. I only remove seeds that have germinated. All of MY crosses are still under refrigeration. I did take them all out for one week during the xmas holidays and then put them back under refrig. I check them every other week.
For disease control of my mother plants I spray them with Banner Max, Compass, and pentathlon. I spray my roses every other week and I’m pretty good at keeping that schedule.
As I had posted several months ago the majority of my hips did not change color even though they were in excess of 100 days old.
No difference in methods of collecting op hips and mine. In fact many of the op hips like 08r507 didn’t change color either. FYI, 08R507 was my top seed producer this year and that plant just completed it’s second year. I guess that is an abnormality.
I will follow your suggestions this Spring and I suspect my seed germination rate will improve significantly. I sure am glad I took the time to collect op hips to work with this winter… Also, my mother plants will be another year older and all will be in 14" pots early this Spring.
Thanks for your help,
Bill Cashin
“Since I grow primarily to produce cut flowers I prune them very heavily.”
Change that. Seriously. If you must grow plants for cut flowers, assign certain plants to the task and designate others as seed producers only. Pruning hard can make a huge difference in seed production.
Bill:
All of my roses were fairly new plants last year and I got zero hip set from my crosses. OP roses set hips, produced seed are in cold stratification now. I’ll be planting the seeds this week. I did a few seeds from embryo culture and got a few of the OP seeds to germinate. So in my very un-scientific opinion, young plants can produce OP viable seed, but crosses are very questionable.
There was a thread several months back that discussed my poor hip set and the consensus seemed to be that many young roses have poor hip set and germination.
Spring is coming and a new opportunity to splash pollen around.
I think that poor hip set and poor germination are two different topics.
In general, I would agree, but do you think the maturity of the rose can have an effect on hip set and seed germination?
I’d say it has an effect on hip set but not seed germination.
I’m not so sure they are completely unrelated topics. I have the distinct impression that early crops from Sequoia Gold and Sequoia Ruby had poor germination rates. A few years later, seeds from these same plants germinated at near 100%. There are undoubtedly multiple factors that govern viability of a seed lot, but I would not rule out the maturity of the seed bearing plant as one factor.
It’s possible there’s a correlation, but even that might not hold true for all seed parents, nor all parental combinations.
It’s going to be true that all seed parents set more hips and more seed per hip as they mature.
If juvenile fecundity is a heritable trait, we are definitely selecting for it.
It would be interesting to see a study. It might make a good university project for someone.
Right on all four counts, Robert.
Bill, were your OP seeds and crosses collected from plants treated the same? Were they pruned similarly? Were they of similar ages? To me, it sounds like there are other factors that might be at play than maturity of your plants. It sounds like you did get viable seeds. I do wonder though about hip maturity. OP hips are often from the first bloom cycle, while crosses may be from the second cycle - especially if you are an exhibitor! 100 days is not always sufficient, although I do recall that ‘Fairhope’ hips do ripen earlier than average.
I have found that stratification differences can account for strangely low germination rates (too wet or dry). Very similar crosses can have widely differing germination rates from one year to the next (probably due to the above).
Regarding young plants, I have noted hip sets and numbers of seeds per hip to increase as plants mature. Many excellent hip bearing roses when mature, may produce few to no hips in the first 1-2 years. Other roses though produce loads of hips right from the start, with lots of seeds that also germinate well.
Jim Sproul
I do not know if this still applies, but when I first started hybridizing in the 70s, my germination rates from commercial garden roses (like Peace) were very poor. I now think that a large part of the reason was because the roses available then were virused.
One of my best seed setters has RMV, I know this for a fact.
Paul, what about the germination rate? My Peace rose was always full of hips. The problem was the germination rate.
I will chime in and concur about the impact plant maturity can have on hip setting and number of seeds per hip. I have experienced this with a number of roses. I noticed this difference significantly when I moved to a new house and started my garden from scratch. Reliable seed producers were fairly weak the first two years in the new garden (dramatically down from what I experienced in my “mature” garden at the old house).
I’d also have to second the comment about making sure that the planned crosses were fully mature. When I first started, I relied heavily on the number of days a hip had been on the plant (I went by 100 days as the target timeline). Now, I use that as a guideline for when to start considering harvesting…but, I will wait until the hip shows some significant color change before I harvest now. I come much closer to about 110 days for many than I had previously. There are certainly some that come in around 100 days with color changes…but most seem to take a little longer for me.
Henry,
It gives me more seedlings than I can deal with most years, but the actual germination rate varies according to the pollen parent used. My ‘Little Darling’ is also definitely virused, and yet its seeds germinate like proverbial weed seeds.
I suspect that ‘Peace’ seeds don’t germinate well at the best of times. Most HT’s have a poor germination rate.
Paul, I was going to say that at that time “Most HT’s have a poor germination rate.” was a common explanation. I now wonder if it was not because at that time most HT were virused, and we were crossing virused mother with virused father.
Do you have any experience with both parents being virused?
“Do you have any experience with both parents being virused?”
Probably, but who knows for sure? I mean, I can safely assume that a significant percentage of the roses I have from commercial sources, varieties that have been in commerce for decades, are likely infected with one or more viruses. No, you don’t often see visual evidence of it, but you can be sure many of these plants harbor at least one virus acquired through bud grafting. (For example, I know for a fact that all three of my plants of ‘Rose de Rescht’, acquired from different sources, all have RMV because all three have displayed visual evidence once or twice in the past 15 years. Most of the time they never show any signs, but all I need to know is that it has definitely shown signs on rare occasions)
I think it is reasonable to assume that most of the older HT’s are all infected with something. And yet, as I mentioned, my RMV infected ‘Little Darling’ sets seed like mad and they germinate easily. If I survey my collection I can likely point to other varieties that set loads of viable seed and yet are undoubtedly infected with virus. In the same way that some varieties are adversely affected in their ability to resist Winter freeze damage when infected with an RMV causing virus and others are not, some varieties will have impaired fertility and others may not. And so…
If you want to draw any conclusions, you need to acquire a virus cleaned specimen of ‘Peace’ and one that you know to be infected and grow both to maturity and compare their ability to set viable seed.