90? 100? 120? Or do you just go by looks?
Hi Judith,
Ping Lim once told us to watch the stem just below the hip and harvest it when it started to turn brown. I donāt record the pollination date as I merely wrap a piece of colored telephone wire around the stem which indicates the pollen parent. But since I make the bulk of my crosses in June and harvest by Halloween, I am typically around the 120 day mark.
John
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This what I used to have in one of my web sites on my Roadrunner web pages about rose hybridizing (Roadrunner closed all customers web pages.).
"When To Pick Your Rose Hips?
A common question is: āwhen to pick the rose hips?ā. Rose hips require a long ripening period - usually 60 to 120 days after pollination. Ripening is indicated by the hip beginning to change color, becoming yellow, orange, reddish brown, olive green, or purplish, depending upon the seed parent. The time period can be shortened by wrapping the hips loosely in aluminum foil ( aluminum foil is discussed in āTo Hasten the Ripening of Rose Seedā,Vera Lebedeff, American Rose Annual, volumn 52, pages 58-59,(1967)). A specific number of days cannot be given as the ripening period depends both on the variety and on the amount of light that the plant has been exposed to.
As the process of ripening continues, the stem will begin to dry (change color) where it is attached to the hip. When this happens, the hip is fully mature and should be picked before it falls off the plant and is lost. Whenever the stem appears to be dying, pick the hip - regardless of color of the hip.
In some areas, the growing season may not be long enough for hips to ripen fully. Leave the hips on the plant as long as the weather will permit. If possible harvest them before the temperature drops much below 32 degrees Fahrenheit ( the exact temperature cannot be given but probably the hips will be undamaged to around 25 degrees. If hips are not fully ripe, cut them off with several inches of stem and at least one set of leaves, place them stem down in water, and store indoors on a sunny window sill to ripen. Add a commercial cut flower preservative to the water.
The following table is from the article: āGermination In Rosa Caninaā, G.D. Rowley, American Rose Annual, volumn 41, pages 70 - 73, (1956). The research was done at the John Innes Horticultural Institution, Bayfordbury, Hertford, England. Do not be discouraged by the fact that there was very little germination the first year. Species R. Canina seeds take longer to germinate than most hybrid rose seeds.
The septals are the green āleavesā that protect the flower bud before the flower opens. They fold downward when the flower is ready to open."
I go by hip and stem color, not day count. Most of my crosses are made in June, and harvested in late October, so the 120 mark seems to be what my roses go by.
Cathy
Central NJ, zone 7a
Yesterday I noticed two hips which had turned orange so they were my harvest of the year. After checking my records I found they were 90 day hips. I have others that have been on longer but they have not yet turned color so I am keeping an eye on them. Usually I harvest at 90 days but it is July 24 and we have yet to reach 100 degrees so I am giving them a few extra days.
This may not be quite on topic, but it gives an idea of the lower limits for embryo rescue:
Plant Cell, Tissue and Organ Culture 21(2): 147-152 (May 1990)
Organogenesis and plant regeneration from immature embryos of Rosa hybrida L.
D. W. Burger, L. Liu, K. W. Zary, C. I. Lee
Results and discussion
Immature embryos of rose turned dark-brown within one week of explanting onto culture media. They appeared to be necrotic until cotyledons began to expand after approximately 4-6 weeks. Complete embryo germination was never observed. The cotyledons expanded and developed into a callus mass that was subcultured onto fresh culture medium and adventitious shoots began to form after 5-6 months. Several adventitions shoots were obtained from on original embryo. All four crosses responded similarly to the culture media. Embryos explanted onto solid media and cultured in the light developed organogenic callus. Rose embryos did not respond well to agitated liquid culture or to culture in the dark. The culture protocol developed to induce adventitious shoot formation included a half-strength, solidified, MS medium containing 1.0 Ī¼M BA and 0.05 Ī¼M NAA and all culturing was performed in the light.
http://booksc.org/book/5723451
Clearly, use of such young embryos does not accelerate the process of getting seedlings, but it might be a useful technique when especially precious hips are dropped prematurely.
[quote=ācathymessā]I go by hip and stem color, not day count. Most of my crosses are made in June, and harvested in late October, so the 120 mark seems to be what my roses go by.
Cathy
Central NJ, zone 7a[/quote]
Normally I harvest around 100 days, but this year Iām going by stem color and there is a tremendous variation. No matter how many days the hip has been maturing, I am waiting for the hip stem to start to turn pale where it is attached at the base. While some have āloosenedā at 90 or 100 days, most are taking quite a bit longer - now approaching 120 days for many of my crosses. The downside to this method is that overnight, some drop and at that point I canāt be certain which cross it was or even which mother plant. Still it will be interesting to see if my germination rate is better. I am also processing and drying the seeds right away which I have never done before, but it sure is a much easier method and definitely easier on my fingers, doing it little by little.
I assume dry seeds in the refrigerator counts as stratification?
Last year was my first where foraging animals were a huge problem, and I harvested my first hips (based on color) by about the end of July, giving them little to no warm time, other than 2-3 days in soggy worm castings, before adding relatively inert potting medium and putting them into the fridge. By September some were sprouting in the bags, and by December a few were a foot tall. Germination rates for some crosses were quite good, so if first flush starts in early April there, as it does here, and you donāt collect uncolored hips, you could probably rush things by that much without forfeiting too many seedlings. I canāt recommend it to any but the desperately impatient, or to those who have gardens in both hemispheres, but I thought it was interesting that it was possible, even if usually a poor idea in practice.
Cathy: I did a very long dry refrigerated stratification last year. I harvested in 2013, dried the seeds for a week or two at room temp, then placed them dry in paper envelopes and then in a ziplock bag in the fridge for over a year, until this spring (I was abroad for a year). My germination rates were dismal. 2-3%, concentrated among only the most willing seed parents I have (Ruby Vig, Tess of the D, Hot Tamale, Morden Cent).
I donāt know if it was the long period, or the dry stratification, but I am going to avoid any dry storage this year.
Hi Donald,
Let me reiterate, Iāve written before about germinating stored seeds before. I am germinating seeds I have stored in the freezer since 2006. I have seedlings blooming this year from those 2006 seeds. Every year I intend to
set aside some space on the germimation table to deal with this backlog of seeds.
"How long will I continue to get germination? " Iām not sure. But this knowledge will help others.
Here is how I handle my seeds. I harvest my seeds when they turn orange or blackish as is the case with plants with
a high degree of spinosissima in them. Here in Z3. Most of my mothers are Explorer or Parkland Roses. These roses
are bred to be early maturing and when field grown must go from flowering to maturity of the seeds in 90 to 100 frost
free days.
When the mother is a Tea or Floribunda rose, itās a little more difficult to decide when to harvest the hips. Sometimes
these tender roses must be sacrificed and kept in the greenhouse in order to mature the seeds.
I work with a greenhouse and cognizant of the time constrains, I try to get my roses out of cold storage and into the greenhouse by mid- April.
No one brought up the issue of Growing Degree Days or Heat units.
Iām not an expert, but I think the geographic latitude of the planting does have a huge influence on the rate of maturity.
Chuckp
Hi Chuck-
Do you dry your seeds before freezing them? Are they in ziplock baggies in the freezer?
I did freeze some seeds from that 2013- about a dozen different crosses. The only ones that germinated were R. rugosa, which sprouted almost immediately after planting. The others were a variety of half-hardy, tender and Canadian crosses.
I really donāt know why I got such poor results. I may have harvested too early that year as I hadnāt dated my crosses. But everything had at least some colour in the hips.
Anyway- I would like to try freezing this year as Iām not sure how much room Iām going to have for germinations next spring. Any suggestions would be appreciated. Thanks!
don
Donald,
My experience is similar to yours. Because of Chucks success with freezing seeds I thought I do a test this past winter. I collected OP seeds from three different seedlings of mine, plants that Iāve had good success germinating seeds in the past. I dried them for four days which I figured would be enough to freeze them without damaging them. After 60 days in the freezer, I took out 40 seeds of each plant. I split them into two baggies of 20 seeds in moist paper towels. One of each went into the fridge and one of each went in the basement. The room in the basement where I put the seeds was 55F to 60F whereas the fridge was about 38F. After 60 days there werenāt any germination yet so I swapped locations of the seeds. Took the seeds from the fridge and put them in the basement and vice versa. After 30 days, three seeds from one plant of the basement then fridge had germinated. I terminated the test because I was moving but I would have liked to have continued the test for another 30 or 60 days to see if there would have been more germinations.
Do you attribute your lack of germination to the drying or the freezing?
Judith- Too many variables in that particular āexperimentā to know.
a) harvested too early? Possible but not likely- the hips had colour.
b) seeds dried? Donāt know- didnāt really have non-dried seeds as a control.
c) seeds stored too long? (1 year) Maybe but Chuckās experience suggests otherwise. And again, no control group.
c) freezing? Maybe for the tender varieties. But the vast majority of my seeds were refrigerated (dry, in packets inside ziplock bags) rather than frozen. Still only had 2-3% germination.
This year, if I have an abundance of seeds (and it looks like I will), I will separate out some for a controlled experiment of sorts: dried vs moist storage in the fridge, frozen vs non frozen. May also do a warm strat/cold strat vs straight into cold strat. experiment too if I have enough seed.
I suspect that drying them had biggest effect on the seeds, but it could be a combination of the two. Years ago I used to dry my seeds before stratification but I later found that seeds that had not been dried out germinated better and that is why my seeds usually go straight from the hips to moist paper towels now. Also, I believe David published a paper regarding what the effect of drying out of seeds has on their germination. I suppose one could do a test with just drying some seeds, just freezing some seeds and with drying and freezing some seeds to see what impact each process has on their germination rates.
Hi don,
I donāt dry my seeds, but they is a lapse of about 3 to 4 weeks between when the first hips are harvested and the
Last ones are ready.
I am so busy with outside work that time I get around to processing hips they are hard and dry and must be coaxed
open with the tip of a sharp knife.
I donāt know, maybe the little extra time between harvest and processing gives the hips a chance to mature the embryo.
Chuckp
I usually harvest hips after theyāve started to turn orange, but before theyāve completely turned color. The number of days depends on the seed parent, and, I suspect, the weather, but itās usually about 100-110 days for modern hybrids. I think that roses native to regions with short growing seasons usually ripen hips faster than modern hybrids. Iāve had hips ripen on R. rugosa rubra in 60 days.
The Rugosa āSchneezwergā is remarkable for early ripening hips - about six weeks (42 days). This means with a second flush of flowers about August 1 I can do another round of crossing with this cultivar and still get mature hips before freeze up. It also means there can be a combination of colourful hips and flowers on the shrub at the same time, which adds to the attractiveness of this rose.
Hi everyone, thought this is too good to keep to myself.
Iāve written quite a bit on storing seeds in the freezer. This is 13 years since I put 2006 seeds in the freezer. Took āRoyal Edward x Loveā seeds out and stratified them. Of 132 seeds, 35 seeds have germinated one month into the three month period of the of warm stratification.
chuckp
Wow, thatās cool, Chuck. Congratulations.
I was just thinking about this topic because today I harvested seed from the polyantha Pretty Polly Pink on potted plants that I had brought inside because the hips were totally green when winter came and I had to shut down the greenhouse. The pollinations were done around July 26th, which my phone tells me is 120 days ago. Most of them were still quite green, with about 1/3 just starting to show some color.