RuthW
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Joined: Thu Aug 21, 2008 10:55 pm
Location: Pendleton, Oregon

Pretreatments to enhance native seed germination.

Hi ... I am interested in finding a way to germinate smooth sumac (Rhus glabra), bitterbrush (Purshia tridentata), and red hawthorn (Crataegus columbiana) species of eastern Oregon (the arid side) which tolerate minimal water.

By the way, use peat moss for moist stratification instead of other media to hold moisture because the acidic peat moss represses fungus growth on the seeds.

TheLorax
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I am not familiar with Purshia tridentata. Had to look that up and I've never propagated anything in that genus before. Sorry.

Haven't propagated Rhus glabra from seed because that plant suckers like a fiend and I don't think a root cutting has ever failed to take. Just dig them up in spring and plop them in something some semblance of appropriate and you'll probably get 10 for 10. One problem, you'll end up with ten clones of the parent. That's great if you're sharing the plants or if you only want females but not so great if you're looking for genetic diversity. Depends on why you're propagating but is also one of the reasons I always prefer to go with seed. I was lazy with the Rhus. There's so much of it around here that I was just playing around to see if the cuttings would take. They took and then they spurted out new growth like gang busters. My bet is winter sowing the seed should do just fine but I've not done it. I could look up protocol for you if you'd be interested.

Have also not propagated Crataegus columbiana from seed but have propagated C. calpodendron, C. mollis, C. crus-galli, and either C. pruinosa or C. punctata from seed. Can't remember which but what ever I got my hands on started with a p. I would think propagation from seed would be very similar for the Crataegus I have propagated from seed as opposed to the Crataegus you want to propagate from seed other than that you could probably reduce your cold moist stratification period to 60 days from the 90 I go by. Eastern Crataegus spp. is a relatively easy plant to germinate from seed. Gather your seed and remove the pulp. Cold moist stratification for around 90 days followed by planting out in trays. Lightly cover the seed by about 1/4" of medium. Some of the seed will germinate in spring however most will not germinate until the following year. Don't toss out your trays if you don't get any germination the first year. I've not used any special medium to germinate these seeds. Just a mish mash of what ever I have on hand that's left over from subsequent years. They don't seem to be all that picky.

Should mention that hawthorns like oaks hybridize readily.

I must admit that I generally winter sow Crataegus spp. Seems to eliminate any risk of damping off. I have placed wrapped some in paper towels and tossed them in zip locks in the frig. If I have any NZ long fibred sphagnum peat laying around, I'll use it for the reasons you mentioned. Great tip you shared. I love NZ LFS.

RuthW
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Joined: Thu Aug 21, 2008 10:55 pm
Location: Pendleton, Oregon

Crataegus spp

Great tips, Lorax.

I have found some natural hybrids between the Crataegus columbiana (red hawthorn) and the C. douglasii (black hawthorn) at one site-source. Three other site-sources have what appears to be pure columbiana. On my homepage, I have posted one photo that shows the stunning and well-armed C. columbiana. This small tree is endemic to the columbia river and a few of its tributaries. C. columbiana is a gnarly twigged (like filbert), squatty hawthorn that grows wider than tall. The fruit seems to have a bit more of the heart stimulant also found in C. douglasii. I have seen wild doves overconsume the red but never the black.

My experience has shown columbiana seeds, without acid scarification, need a very long cold strat interrupted by short warm then a second 'winter'. I never allow seeds to dry, put them straight to cold moist strat for 10 months, then warm for 2, then cold again for 6. I would like to be able to shorten this procedure a bit. I wish there were some zoo that wanted to go into cooperative seed scarification through their bears! They could reduce their food bill while clearing a profit on the prestratted seeds if they didn't mind cleaning them up a bit first.

By the way, last year I used an easy method for obtaining near 100% germination from the recalcitrant Acer glabrum douglasii, douglas maple, if anyone is interested.

TheLorax
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Joined: Wed Feb 20, 2008 2:40 am
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Good old stomach acids can do wonders to scarify a seed. I know people who intentionally feed seeds to their goats and to their parrots to be able to experiment.

Have you ever tried to scarify Gymnocladus dioicus just for giggles? To do so is about the equivalent of scarifying a marble. You think you have a grip on them and all of the sudden they start pinging all over the room before you even get a chance to nick them. Think about trying to file a marble using a dremel tool and missing the marble and hitting your finger or hand- big ouch. I finally started ramming them in vices to avoid damaging my fingers. Anyway, I often have wondered which animal once provided the acid scarification for that species before we humans had to step in to provide it artificially.

I've sped up the process of double dormancy seeds before doing just about what you outlined. Totally doable. Just mark your baggies and trays lest you stand there over them like I have in the past trying to remember when you started what. I still think you can go 60 days on the columbiana for both the cold moist strat and the warm moist strat so that means you could easily cut your time down to 1 year. Use a nail file to scarify the seed then soak them in room temp water for 24 hours then change to fresh water for another 24 hours and maybe dip them in a solution of 10% bleach before sticking them in the ziplocks. Tip- don't use GA3. Don't have time to get into the why nots but not a good idea when you are accelerating Mother Nature's tried and true method of germinating her seed to use it. Get the soil temps in the tray up to around 70 for the warm moist strat and keep them there. Maybe stick your tray on a heating pad set to low and cover it with cellophane to keep the moisture in should you have any dry spells. You could buy expensive heat mats. I've got them. They don't seem to work better than $12 heating pads that don't have automatic shut offs after an hour or so. Yup, figured out I had bought a heating pad that had an automatic shut off once. Could not for the life of me figure out why every morning when I went to check on my tray that the heating pad was always off. Told the kids to stop screwing around by my plant trays. I'm sort of allergic to reading directions on products. The heating pad I had purchased had an auto off feature in the event somebody forgot it and left it on and if I had bothered to read the little instruction papers that had come with it, I would have figured it out. Had to buy a real cheap heating pad that didn't have that feature to solve that problem. Also too, if you are doing this inside your home, train a small desk fan on your seed. Keeps the air circulating.

Say, I added your nursery to the Native Plant Nurseries for North Americans. Thanks for suggesting it. I'd not run across it before and it's a great addition.

Correction- the Native Plant Nursery where you work. Sorry about that.

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