rhododendron seed starting

[Sadauskas]

hello all,

just received my seeds and was looking for some seed starting basics on rhododendron kinsai x showa-no-homare and r. shiryu-no homane x mine-no-hoshi(hope I got all that right).  I am quite unfamiliar with rhododendrons, but wanted to give some a try.  I read something about spahgnum medium, and just wondered if any rhododendron growers might want to chime in?

thanks
michele

[Todd Boland]

I hybridize rhodies so know all about sowing them.  Here is my technique...others may differ!  I use peatmoss (horticultural grade) that has been sterilized.  I fill the pots, water and let drain for a while.  I then surface sow the seeds and place syran wrap over the pot surface, held in place with an elastic band.  I then place the pot under flourescent lights (or a bright window shaded from direct sun) then wait.  The seeds normally sprout in about 2-3 weeks.  I leave the plastic in place for another 3-4 weeks before I remove it.  In about 2-3 months, the seedlings will be large enough to prick out (wait until about 2-3 true leaves have formed)

Good-luck!

[RickR]

Todd's method is essentially the same as what I have done.  I too, used pasteurized peat, surface sow and enclosed pot and all in a clear plastic bag, set on the north sided of my house in open shade.  The warm cozy inside temperature that he uses is certainly a plus.  Seedlings grow slowly in my experience.  Now if I could just keep the chipmunks away . . .

[IMYoung]

Todd is a great Rhodo man, I know, and he and Rick are living in North America so their methods are surely pertinent.
Michele mentions the sphagnum method and I thought you might like to see a couple of old articles from the SRGC journal on the subject?
I have made pdf files, very rough and ready, but  readable I hope, of these... the first by the late Alec Duguid, (the man who did great things  as manager at Edrom Nursery in the Scottish/ English border country) from the SRGC Journal #72 of June 1983  and the second, a response to that article, detailing the method that Ian and I used, from the "Rock Garden" #90 of January 1992 .

At that time we were sowing in the moss alone but nowadays we would use a layer of sphagnum moss over a compost mix rich in leaf mould for ericaceous subjects.

Hope these "blast from the past" items are of interest!

[Sadauskas]

It was nice to open up the forum and see what tidbits of info I received   Thank you everyone for your input.  Todd, I will add my rhodo seeds into my line-up of containers. I set my pots up exactly as you describe...just will do the peatmoss instead of my normal mix.  Thank you to RickR and Iam too.  Looking forward to the nargs forum to be as wonderful as the srgc forum

[Rimmer]

Maggie your post from the SRGC was wonderful to read.
I have been using sphagnum as a mulch when starting cuttings of rhododendron (Ledum) and Daphnes with great results

Rimmer

[Gene Mirro]

I have two lots of R. occidentale, one of which I collected myself, so I know the seed was fresh.  Both have been sown for two months now, with no sign of germination.  Aren't these plants supposed to be "immediate" germinators at room temperature?  I am an experienced grower, so I'm pretty sure I haven't done anything boneheaded. 

[Todd Boland]

Gene, rhodo seeds should germiate within 2 weeks.  The key is surface sow and keep at 100% humidity.  I cover my pots with saran wrap until I see the first true leaf emerge.

[Gene Mirro]

I tried another batch, and they came up like grass.  They definitely need to be surface-sown.

[IMYoung]

I'm pleased the old info proved interesting.

We always reckon that the finer the seed (and rhodo seed is pretty dustlike) the shallower it should be sown, so the surface sowing is perfect and, as Gene has shown, works a treat. 

[Moyles]

Just an additional note:  I think we all germinate rh seed in pretty much the same way: surface sown on milled sphagnum covered under lights with germination generally in 30 days or less. If one is interested I have a paper in which I detail my approach  (A Vireya Seed Ody ......... etc) that is viewable in the archives of Callard's site: Vireya.net.  All ericaceous seed are easily germinated in this way. In any case Vireya.net is worth the trip!  A marvelous site. 

[RickR]

A wealth of other info on that site, too.  Thanks for sharing it.

And welcome to the forum, Bill!

[Gordon]

I have a question about Rhododendron seed longevity. Since my efforts to find plants of Rhododendron augustinii for sale in Nova Scotia have been fruitless, I went looking for seed sources. Van Dusen Botanical Garden in Vancouver, BC has packets for sale, but they were collected in January of 2009. R. augustinii is high on my wishlist, so I am tempted to order a packet anyway, but wonder if the seed would simply be dead at this late date. Does anyone have any advice, or a source of fresh seed I could contact?

[Whitehead]

Gordon,

I have about four clones of augustinii.  I don't think I got them all deadheaded so there ought to be seeds for you.  Or, since you're in Canada, I could just mail you a batch of cuttings.

Diane
Victoria

[Gordon]

Thank you Diane, I am looking forward to germinating seed from your plants, and possibly attempting cuttings as well! Hopefully a few plants will come of all this... love seeing new plants work their way into the landscape. Last years' seedlings were Digitalis obscura and Kniphofia triangularis. A few Enkianthus sp. seedlings have germinated, along with Poncirus trifoliata.