I’m having trouble germinating gigantea seeds. They seem to take forever to germinate. I gave mine a good 8 weeks or so in the fridge with peat and am still not getting anything pop up. It’s been almost a year in the ground so far. Digging the seeds up to check shows them almost unchanged. Still hard as little rocks.
So nobody has germinated gigantea seeds before???
I germinated one or two many years ago–out of a great many seeds sent by one of your not-do-close neighbors in OZ. The seedling I remember was weak and had a single and pale flower. If it hadn’t died on its own, I wouldn’t have worked hard to keep it alive. You might get better results extracting the embryos, or reading up on how Alister Clark germinated the seeds. I obviously know nothing more than you do about how to germinate gigantea seeds.
Peter
I did get two to grow out of packet of seed (30 seeds?) I bought from a British seed catalog. Like Peter my two small seedlings died. I also got some seed from Paul I believe but these never grew. I am a little glad, however I do not know what I would do with them any ways. I would have had to figure out a way to grow them part of the year inside. Plus they make really large plants. I still have to shake my head and wonder what I was thinking. Maybe if I ever have a greenhouse I would experiment with it.
These are seeds Viru sent over and I have tried the embryo extraction and failed at it. The achene is really thick and hard with a comparatively small embryo that is tightly wedged in the middle. Even after long drying periods the embryo doesn’t seem to shrink much to make extraction easier. I did see one online reference say that it can take up to two years in habitat. I’ve got the book written on Alister Clark called ‘A Man of Roses’ and doesn’t detail much about his methods of germinating any thing really. I have a plant of gigantea growing up a dead eucalypt in my back paddock but was interested in growing these seeds as Viru said they were from Manipur in India and may offer different traits to work with than the variant of gigantea we already have. I’ll contact Viru as well and see what he says.
I tried Sanguinea seeds, which I assume are similar given their similar native locality and close genetic relation. They didnt germinate – I am sure they may have given more time and seasons, but I didnt care at that point.
One of the biggest mysteries is where R.gigantea entered the gene pool of modern roses. I didn’t include gigantea in my major descendency chart simply because it wasn’t documented in any significant ancestry but judging from the growth habit of the hybrid teas and the thickness of their pericarps it seems pretty clear that both traits originated with R. gigantea.
Large rose seeds (those with thick pericarps such as from the HT’s, gigantea, the spins and acicularis) are among the easiest to split using the gadget if they are quite dry and have not been stratified (which makes the pericarps mushy).
I always assumed that the Chinese created teas with them. I know that it is said that the original tea hybrids have R. odorata in them, which is also known as R. gigantea. I’m assuming that is where the fade-prone yellow tones came from. I’m sure they probably have R. chinensis in them as well. What I would like to know is if the Chinese bred other tea roses that never made it into global commerce.
Oh yeah, I forgot two notes.
Notice how well Evergreen Gene’s petals scroll. Even though it is half-HT, I cannot imagine many other species first descendants with an HT pass on such smooth petal scrolling. It seems to be a rather fluid trait in R. gigantea. Another thing to note is that Hume’s Blush Tea-scented China, which is bred from R. gigantea, is probably found in more than what is listed in lineages. Papa Gontier, Dr. Grill, Madame de Tartas and Park’s Yellow Tea-scented China are the main donators of tea genetics into a large chunk of modern roses. Its always possible that Park’s Blush Tea-scented China is found in any of the former three roses. Park’s Yellow Tea-scented China is found in a huge majority of modern roses, likely descended from R. gigantea and is found in such popular teas such as Safrano and Devoniensis.
I don’t think there is any “trouble” as such in this case. These achenes are so concrete-like and the pericarp is so thick, one would expect them to take forever to germinate after sowing them.
As for embryo work, drying the achenes (even 24hrs of surface drying) definitely makes pericarp removal MUCH easier to achieve (as Don noted) no matter what method of extraction you are comfortable using. There is better surface grip, and less likelihood of the achene slipping and becoming a facial projectile (or causing a knife to slip on a finger in the case of using a box-cutter knife).
If you have a good number of these, and if you are getting great results with embryo work in other cases, then I would definitely retry embryo extraction and cutlture on some of this seed. However, if your embryo skills are not great, then just leave 'em alone to germinate, as you already are doing!
As I said before… I tried embryo extraction. The seeds weren’t easy to split using clippers and a gadget I made and I was not able to extract the embryo without destroying them even after several weeks of drying because they were still tightly wedged in with little or no play in them. I did it before I attempted stratification… in fact I stratified them because I found extraction so difficult.
Peter, did your gigantea seeds take an unusually long time to germinate? Did you treat them any differently?
Simon,
The seeds I had were not from the species. They were OP seeds from 4-5 of Clark’s gigantea hybrids. Two of them (if I remember correctly): Golden Vision, Jessie Clark. I think both seeds that germinated were from Jessie Clark. One germinated but never really grew, and the other germinated, developed 3 true leaves, produced a single bloom with petals about as pointed as the leaves, and then just stayed under the lights for a long time without showing any desire to grow further. Finally it dwindled away.
I treated the seeds as I did any others at the time, sowing them in flats which I kept in a cold (40-50 F) garage. Germination was not really good overall that year, but these under-excelled more than most. They were huge seeds, something like large buckshot.
Peter
Oh, I forgot to say, I am also more than happy to extract and germinate a few of these for you, (using another method).
The only thing is, how do you get the seedlings back through quarantine??
Peter, these seeds are exactly like you describe. Big seeds some 7-8mm long and 4-5mm high. The seeds are like little stones. I have seeds from ‘Lorraine Lee’ (x ‘Mutabilis’) and ‘Nancy Hayward’ (OP) here as well and these seem a little more like typical hybrid seeds but are still large and are also taking a long time to germinate. This is the second batch of gigantea seeds I’ve tried to germinate. The first was from a batch originating in Australia (NSW), about 4 years ago. They are still in a pot outdoors with no germinations… I just leave them somewhere out of the way and forget about them. This lot, as mentioned above, have been in the pot now for almost a year. To be fair, it is still winter here. Maybe once things start warming up a bit they will start popping up. Everything else is germinating already but these guys are not even showing any signs of discolouring the achene.
Is it because of their native locale that the seeds are so, uhm, “gigantea-ic” :)From photos, it looks like their native locale has a lot of decomposition like here in the PNW, but sub-tropical instead of temperate. Maybe this was protection against rotting before germinating? Or a way to be carried from water mobility?
I wish I had more time to try Sanguinea. I wanted to badly mix it with yellow diploids. Personally, Mutabilis is a bit disease prone here unlike Sanguinea. Mutabilis also has more delicate petals and smaller blooms. It would have been cool to see if the color deepening trait could be passed on to create a rose like Mutabilis but with better horticultural traits.
The 2nd lot of seed were stratified in peat to encourage decomposition… maybe stratifying them with compost seeder might work, however, I was hoping the peat would do the same thing. My thinking of ‘Lorraine Lee’ x ‘Mutabilis’ was to incorporate the yellow → pink colour change into a Tea-like shrub… like a shrub form of Fortune’s Double Yellow. Lorraine Lee’s flowers are almost like that as it is but are nice and thick to compensate for lack of substance in Mutabilis. I’m picturing a plant with the shrubbing nature and yellow-shift of Mutabilis and the flower form and health of ‘Lorraine Lee’ (Lorraine Lee will get mildew here though Mutabilis gets no disease here).
Its really weird cause its not mildew Mutabilis gets here. Its either black spot or anthracnose or some such. I’m almost guessing its one of the diseases lke anthracnose.
I wish I knew more about roses like Lorraine Lee. A lot of the Aussie bred OGR types (tea/china/polyantha/climbers etc) are in my books but Id love to see them in person some day.
Lorraine Lee is a rose that a lot of Aussies are really patriotic about. There are places where it is grown everywhere and you couldn’t call yourself an Aussie without at least one growing in your front garden. A country town I use to live near called Armidale, in the NW of NSW (you might have heard of Tamworth… it’s near there) has loads of it. Driving through town in late autumn was amazing. The climbing form and bush form cover every fence and arbour in town. Toowoomba was like that too only not to the same extent as Armidale. I think Robert has/had Lorraine Lee. They are over there… just a bit like hen’s teeth I reckon. If you are ever down this way drop in and I’ll take you for a tour to show you the Aussie-bred roses 
‘Mutabilis’ is clean as a whistle here and evergreen/everflowering. I just find it difficult to germinate the seeds so have used it a lot as a Dad instead.
‘Lorraine Lee’ didn’t like my climate very much, and it mildewed. I gave it away. It was very fertile as pollen parent. I think I only tried it on a few blossoms and I still have descendants.
I made a banksia derivative that’s setting hips. I also used it with one of Viru’s first generation gigantea hybrids.
That seedling is very vigorous but no signs of flowering as yet.