Do rose seeds behave like Rubus seeds?

Henry recently started a thread on apple seed germination. Since apples belong to the Rosaceae (rose family), the results may apply to rose seeds. The genus Rubus (raspberries, blackberries, etc.) also belongs to the Rosaceae. Roses may be more closely related to Rubus than to Malus (apples). Rubus species resemble roses (prickly canes), and have the same basic number of chromosomes as roses (14 chromosomes in diploid species). The growth habit of apples is different (prickle-free trees), and the basic number of chromosomes is different (34 chromosomes in diploid species). Research on Rubus germination might apply to roses. Here is an excerpt from a page on raspberry breeding (see link below):

Seed germination has improved remarkably over the last two decades. Our 1979 crosses germinated at a rate of approximately 3-10%. This year germination was complete on some crosses; we saved only 20,000 seedlings however. Here’s how we do it.

Plants are pollinated in a greenhouse from mid-January to early April, when bee activity outside is too high. Plants are grown in pots and given over 1200 chilling hours in a 40F refrigerator. Males are brought out two weeks earlier than male/females which are brought out two weeks before females. Most of these parents are hermaphroditic, so the terms male and female are only functional, pollen is collected by harvesting flowers before anther dehiscence and females are emasculated at first petal showing in raspberry, a day or so later (balloon stage) in blackberry. Anthers are removed from the flower and dried over Drierite (Calcium chloride pellets) overnight at room temperature. They are stored for short periods closed in their Falcon 1006 petri dishes over Drierite (in Ball Jars) in the refrigerator for short periods or in the freezer for long periods (they are viable for over 2 years). Anthers are crushed with a flat surface to release pollen. Females are pollinated immediately after emasculation, a day later and two days later. Flowers are not covered. Field pollination would be different, but it is impossible in Maryland, not so in cooler areas. Fruit are harvested at ripeness, stored in a refrigerator until all like crosses are collected and blended in a Wareing blender at full speed to release the seed (ca. 5 seconds). The water is decanted, new wash water is then redecanted and seeds are collected on a seive. Seeds are dried on paper towels overnight, collected in 1 oz glass tablet bottles (French Squares) and stored at 40F until use. I like to have them just a touch moist (sometimes a little fungus develops in the bottle), but full dry is good for long term storage. They need to be dry to survive the scarification treatment. Seed is scarified by placing it in its glass bottles on an ice bath. Concentrated 96%+ sulfuric acid (chilled) is poured to cover the seeds plus another half cm. Seeds are always kept on the ice bath. After 30 minutes for raspberry and an hour for heavier seeds, the acid and seeds are poured into water through a seive which catches the seeds. (NEVER THE POUR THE OTHER WAY-DON’T LET WATER GET INTO THE JARS OF ACID-CONC ACID IS DANGEROUS, HAVE SODIUM BICARBONATE AVAILABLE TO NEUTRALIZE ANY BURNS). Wash the seeds in running water for a minute and add 1% sodium bicarbonate to neutralize the acid. Leave this for 10 minutes and catch the seeds on the sieve and wash them in water. Scrape the seeds back into the jar and add the second scarifing solution, 3 g/liter of calcium hypochlorite (70% available chlorine) in excess calcium hydroxide (you add the hypochorite to water, stir for 40 min and then add the hydroxide). Work in a ventilated room as the HYPOCHLORITE CREATES TOXIC CHLORINE FUMES. Place the filled jars with the seeds and solution in the refrigerator for 6 days. After the seed coats have been softened again, take them out of the refrigerator and wash them in water (decant the solution off and add new water, shake a bit and decant again). Invert the clean seed in water on your palm and let the solution and seeds “woosh” onto the seedling pot by quickly sliding the jar off your hand (while it is above the pot). Do not let the seeds dry or cover them. Our seedling pots are filled with vermiculite to an inch below their rim and covered with screened peat moss or BX soilless mix and moistened to run off. The seeds in their seedling pot are misted overnight. This is an important step as it starts the fungal activity (we used to call this warm stratification). The pots are placed in plastic bags (en masse in trays) and placed in a refrigerator. After 10 weeks, the seeds should be covered with a fungal mat: this is good, excellent in fact. Seedling pots are placed in a mist under continuous light for germination. (It’s usually October when I do this). Germinated seedlings are harvested and placed in 50 cell trays for further development. But wait, we’re not finished. Black raspberries, hybrid berries and blackberries (and some northern raspberries) do not germinate yet. I give them another 6 weeks in the refrigerator and bring them out for another germination session (this time its usually January and I only need the mist for a week or two). I plant the seedlings as growing plants in plastic mulch with trickle tube using water wheels, or we have used tobacco transplanters to plant in no-till fields. GOOD LUCK and be careful----all the dangerous methods above have been published in the scientific literature, so don’t try and sue me for trying to help raspberry breeders.


Rubus seeds are deeply dormant, and may remain dormant for years. This study showed germination rates of up to 84% for Rubus seeds that had been stored for 22-26 years:

Title: Longevity of Rubus seeds after long-term cold storage.

Author: Clark, J.R., and Moore, J.N.

Source: HortScience : a publication of the American Society for Horticultural Science. Sept 1993. v. 28 (9) p. 929-930.

Abstract: Seeds of 25 blackberry (Rubus spp.), five red raspberry (R. idaeus L.), and two black raspberry (R. occidentalis L.) populations that had been stored for 22 to 26 years were planted in the greenhouse to evaluate their germination. Germination ranged from 0% to 84% among all populations. Thorny and thorny x thornless blackberry populations had the highest average germination; most populations had less than 40% germination. Thornless blackberry populations ranged from 1% to 16% germination. The seeds of two of the five red raspberry populations did not germinate and none of the black raspberry seeds germinated.

This study showed that although Rubus often appears in burned areas, fire apparently does not stimulate the germination of Rubus seeds:

Title: Fire effects on germination of seeds from Rhus and Rubus: competitors to pine during natural regeneration

Author(s): Cain, Michael D.; Shelton, Michael G.

Source: New Forests 26: 51-64, 2003.

Abstract: Throughout the southeastern United States, Rhus and Rubus species are common associates of the southern pines on a wide array of upland site and stand conditions. Because of their ability to overrun disturbed sites, these species are categorized as competitors to pine during stand regeneration. Since prescribed burning is often used for site preparation in advance of pine regeneration, this study investigated the effect of fire on the germination of seeds from three pine competitors (Rubus argutus Link, Rhus copallina L., and Rhus glabra L.). During dormant-season burns, sumac seeds were located 45 cm above litter, within the F layer of a reconstructed forest floor, and at the interface of the forest floor and mineral soil. During growing-season burns, fresh blackberry fruits were placed at heights of 0, 15, 30, and 45 cm above the surface litter of a reconstructed forest floor. In subsequent germination tests, sumac seeds from within the F layer of burned litter had significantly higher germination rates for smooth sumac (31%) and shining sumac (42%) as compared to unburned control seeds (1-5%). In general, germination rates for sumac seeds placed in the air or on mineral soil during burning were no better than control seeds. Seeds from blackberry fruits that were located at heights of 15, 30, and 45 cm had germination rates that were comparable to unburned control seeds (18%), but seeds from fruits placed on the litter during burning had <1% germination. Results suggest that sumac seed germination may be enhanced by the heat from prescribed burning, whereas blackberry seeds showed more germination response to multiple germination cycles which indicated a potential for long-term storage in the soil seed bank.

There was an article on the Internet some time ago which showed that rose seeds eaten and excreted by cattle had a much higher germination rate than uneaten seeds. I can’t seem to find that article at the moment. Here is an abstract of an article on the effect of different kinds of manure on Rubus germination.

Article Title: Effect of manure composition on seedling emergence and growth of two common shrub species of southeast Alaska.

Author: Traveset, A.

Other Author(s): Bermejo, T. Willson, M.

Source Info: Plant ecology. Plant ecol. July 2001. v. 155 (1) p. 29-34. ISSN 1385-0237; VGTOA4

The idea that fecal material accompanying vertebrate-dispersed seeds at deposition sites plays an

important role in enhancing seed germination and seedling survival has, surprisingly, little empirical support. The present study attempts to experimentally test this hypothesis. We examined the effect that manure composition from brown bears (Ursus arctos), important seed dispersers of Rubus spectabilis and Vaccinium ovalifolium/alaskaense in the temperate rainforests of Southeast Alaska, has on seedling emergence and growth of these two fleshy-fruited species in their natural habitat. The seeds of Rubus spectabilis showed a significantly higher germination rate in manure composed of animal material (mainly deer hair and bones) than in manure consisting of either fruit pulp or vegetation fiber and than in controls (potting soil with no manure added). The final number of germinated Rubus seeds was similar between the animal material and the fruit pulp treatments, perhaps due to similar water retention capacities, but was significantly higher than in the vegetation fiber treatment and the control.

On the other hand, this study showed no increase in germination of seeds that had passed through the digestive tract of various animals, but did show an increase in germination following a 20 minute soak in concentrated sulfuric acid:

Article Title: Effects of perturbations and stimulants on red raspberry (Rubus idaeus L.) seed germination.

Author: Lautenschlager, R.A.

Source Info: Forestry chronicle. For. chron. July/Aug 1997. v. 73 (4) p. 453-457. ISSN 0015-7546; FRCRAX

Abstract: Red raspberry (Rubus idaeus L.) seeds germinate only after seed coats are degraded. In nature this happens slowly. Seeds from recently collected fruit (fresh to four years old) germinated only after scarification of the seed coat by 20-minute soaking in concentrated sulfuric acid. Germination was not enhanced by: (1) short-term intermittent soaking, up to 81 hours, in dilute (0.01 normal) hydrochloric acid; (2) passage through the digestive tracts of bears, coyotes, or birds; (3) physical perturbations such as nicking, mechanical scarification, repeated freezing and thawing and/or four years of exposure in the field; (4) exposure to light;(5) increased temperatures or temperature fluctuations; or (6) addition of nitrogen (ammonium nitrate, urea).

Jim, I have a link to the cattle eating rose seeds on my web page.

The link is:


Here’s another study that showed a significant increase in germination following a soak in concentrated sulfuric acid:

Article Title: Pregermination studies with liquid nitrogen and sulfuric acid on several Rubus species.

Author: Peacock, D.N.

Other Author(s): Hummer, K.E.

Source Info: HortScience : a publication of the American Society for Horticultural Science. HortScience Apr 1996. v. 31 (2) p. 238-239. ISSN 0018-5345; HJHSAR

Abstract: We contrasted the effect of liquid nitrogen (LN2), sulfuric acid (H2SO4), and a nontreated control on the germination of six Rubus species. We also were interested in determining if LN2 could be an effective mechanical scarifying agent for these species. Seeds of each species were treated with three 3-minute dips in LN2 with alternating 10-minute thaws, with H2SO4 for 30 minutes, or left untreated. The percent germination of R. multibracteatus A. Leveille & Vaniot, R. parviflorus Nutt., R. eustephanos Focke ex Diels, R. leucodermis Douglas ex Torrey & A. Gray, R. ursinus Cham. & Schldl., and R. chamaemorus L. treated with LN2 was not significantly different than the control. Germinated seedlings from the LN2 treatment of each species showed normal development upon planting, indicating that long-term cryogenic preservation of these Rubus species seeds may be possible. The H2SO4 treatment significantly increased the rate and percentage of germination in R. parviflorus, R. eustephanos, R. leucodermis, and R. ursinus over that of the control and the LN2 treatment. The alternative LN2 application techniques that have been attempted thus far have not significantly improved Rubus seed germination compared with that of the control.

Henry, thanks for the link to the article on cattle eating rose seeds. Thanks also for posting the Agricola link where I found many of these articles.

This study showed that dried Rubus seeds had much lower germination rates than seeds that were not dried:

Article Title: Drying interferes with germination of blackberry (Rubus sp.) seeds in vitro.

Author: Mian, M.A.R.

Other Author(s): Skirvin, R.M. Norton, M.A. Otterbacher, A.G.

Source Info: HortScience : a publication of the American Society for Horticultural Science. HortScience Feb 1995. v. 30 (1) p. 124-126. ISSN 0018-5345; HJHSAR

Abstract: To study the causes of low germinability in dried blackberry seeds, seeds harvested from fresh ‘Thornless Evergreen’ (TE) blackberry (Rubus laciniatus Willd.) were either air-dried (12, 24, 36, 48, 60, 72, 96, or 120 hours) or explanted directly onto growth-regulator-free medium after bleach disinfestation. Seeds were either cut in half before explanting or kept intact. None of the intact seeds germinated. Fewer of the halved seeds dried 12 hours or more germinated than control (fresh moist) seeds (42.7% and 54.5%, respectively). Germination decreased to 48 hours of air-drying. In a separate study, fresh seeds of TE and ‘Navaho’ were either dried as described or held in sealed petri dishes on moist filter paper (moist treatment) for up to 60 hours. After 60 hours, germination of dried seeds of both cultivars had decreased significantly; there was no significant change in germination percentage for moist seeds. Since moist halved seeds germinated well and dried halved seeds did not, the inability of dried blackberry seeds to germinate is due to more factors than just the hard seedcoat typical of the genus.

This study showed that nitrates stimulate germination of one Rubus species:

Article Title: Nitrate fertilization stimulates emergence of red raspberry (Rubus idaeus L.) under forest canopy.

Author: Jobidon, R.

Source Info: Fertilizer research. Fertil. res. 1993. v. 36 (1) p. 91-94. ISSN 0167-1731; FRESDF

Abstract: Nitrate-nitrogen fertilization triggered germination of dormant Rubus idaeus L. (red raspberry) seeds naturally buried in the forest floor of 50-year-old coniferous stands of eastern Quebec. Orthogonal contrasts revealed a significant linear effect between the rates of nitrate applied and red raspberry seedling counts over two consecutive growing seasons. The fertilization treatments stimulated emergence to a greater extent inyear 2 than in year 1. The potential effect of nitrate on raspberry seed dormancy breakage is briefly discussed in relation to site disturbance.

Here are some older articles that might be of interest. These were published before 1990, and the abstracts don’t seem to be available on the Internet. Perhaps someone with access to a research library could look them up.

Title: Pregermination treatment of seeds of species and hybrids in Rubus with sodium hypochlorite.

Author: Galletta, G.J.

Other Author(s): Ballington, J.R. Draper, A.D.

Source Info: Acta horticulturae. Acta Hortic Nov 1989. (262) p. 289-295.

Title: Seed size and number in Rubus chamaemorus: between-habitat variation, and effects of defoliation and supplemental pollination.

Author: Agren, J.

Source Info: Journal of ecology. J Ecol Dec 1989. v. 77 (4) p. 1080-1092.

Title: Enhancing seed germination of sand blackberry.

Author: Campbell, P.L.

Other Author(s): Erasmus, D.J., Van Staden, J.

Source Info: HortScience. Hortscience June 1988. v. 23 (3) p. 560-561.

Title: In vitro germination and growth of Rubus seeds and embryos.

Author: Ke, S.

Other Author(s): Skirvin, R.M., McPheeters, K.D.

Otterbacher, A.G., Galletta, G.

Source Info: HortScience. Hortscience Dec 1985. v. 20 (6)

p. 1047-1049.

Title: Pollen longevity of blackberry cultivars.

Author: Perry, J.L.

Other Author(s): Moore, J.N.

Source Info: HortScience. Hortscience Aug 1985. v. 20 (4) p. 737-738.

Title: Pollen viability assessments in blackberries (Rubus subgen. Rubus).

Author: Nybom, H.

Source Info: Plant systematics and evolution. Plant Syst Evol 1985. v. 150 (3/4) p. 281-290.

Title: Respective effects of endocarp, testa and endosperm, and embryo on the germination of raspberry (Rubus idaeus L.) seeds.

Author: Nesme, X.

Source Info: Canadian journal of plant science = Revue canadienne de phytotechnie. Can J Plant Sci Rev Can Phytotechnie Jan 1985. v. 65 (1) p. 125-130.

Title: Acceleration of the reproductive cycle of the cultivated blackberry.

Author: Lundergan, C.A.

Other Author(s): Carlisi, J.A.

Source Info: HortScience. Hortscience Feb 1984. v. 19 (1) p. 102-103.

Title: Studies on germination in raspberry (Rubus idaeus L.).

Author: Dale, A.

Other Author(s): Jarvis, B.C.

Source Info: Crop research. Crop Res Nov 1983. 23 (2) p. 73-81.

Wow, I didn’t know that Rubus can be so dormant. Several years ago I was able to pick some raspberries from a mixed population of primocane fruiting plants in the fall and just mushed up the berries, decanted the pulp, and planted the seed right away and they came up well in the cool basement.

It seems that with some species that freshly planted seeds germinate well, but if they are dried and stored, then secondary dormancy sets in and needs to be overcome. Maybe I was just lucky with my Rubus or that fresh seed of Rubus can be planted right away with less dormancy issues. It can be a problem to plant right away if someone cannot manage the seedlings right away.

Higher and more uniform germination with seeds of perennial herbaceous or woody species planted right away also seems to be the case for birch, blueberries, cranberries, daylilies, and azaleas. This was the first year I planted azaleas from seed and amazed how quickly and they came up and how large they are already (couple inches). I got carried away and have over 1,000! I always had the impression that they were tough to grow and finicky, so I planted lots of seed and planted it thickly. They probably don’t look that good in my area just because of high pH soils people seldom amend enough and powdery mildew come summer.



P.S. Maybe it would be worth contacting Christine Naess in Canada or the Rubus breeder in Beltsville, Maryland to ask them what treatments they have found works best on their Rubus seeds.