Hello

Im also growing many conifers from seed Sheffields is my main source.
Ive just sown some Thuja occidentalis seeds in a peat grit
mix in a heated propagator source Sheffields seeds
New York. Thuja plicata self seeds in a plantation not far from
here.However its a fast growing tree.The other species
are slowgrowing good luck with your germinations.

Never tried growing it deliberately - around here, it regenerates on its own freely, without any assistance at all. Probably the conifer second most free to do so here, after Tsuga heterophylla.

Diseases - you'll need to watch out for Didymascella thujina. Ask Hørsholm Arboret for more info, they have done a lot of research on it.

Resin

Here is a link that might be useful: Didymascella i Thuja (Dansk)

Greetings I live in the northwest U.S. and Thuja plicata grow well here. I have many seeds which I collected this spring. Would you like some? I start my seeds in zip lock bags in a 50/50 sand and peat moss mix. It works well but can take up to several months depending on the time of year I begin. I also have some of this years Douglas Fir seeds. Good luck

Hi

Yes I would much appreciate some Thuja plicata seed
please Email me

Hi, one week have passed and my seedlings haven't grown any higher. But the first signs of the "real" leaves are appearing, although still around 0.5mm.

One problem is that the seed scale is still firmly attached to the 2 cotyledons.

/Hans Olav

Now I have manually removed the seed scales from the cotyledons.

And 1 more seed have germinated - now at 25% (without stratification, with scarification).

/Hans Olav

Another new germination today (nr. 5). Nr. 4 looks as if it is not going to make it - looks like only half a seedling.

The 3 oldest now have 3 sets of needles
1) The two cotyledons
2) A pair of very small juvenile needles
3) A quartet of very small juvenile needles

/Hans Olav

Time for a short status:

None of the new germinations have survived - dunno why. Another one just started germinating, but I doubt anything will come from it - it looks kind of strange.

The first 3 seedlings are doing just fine - also after my 14 days holiday during which time weather was unusually dry and hot. (I had set up some automatic watering...)

The 3 seedlings still have their cotyledons as well as many (more than 10) juvenile needles grouped in a tuft at the top. Height is unchanged approx 2cm (= 4/5 inch)

/Hans Olav

Hi honymand

Slightly off topic I have a book on conifers with a
photo of Thujopsis dolabrata 'cristata' is this plant
grown in Denmark? please Email me.

Thanks

Torreya 2006

I'm having some Kootenai-source wild-type Thuja plicata seeds mailed to me from Lawyer Nursery. When they found out I only wanted about 50 seeds, they volunteered to send them to me at no charge(!) -- what great people!

I'm wondering how best I should go about germinating them, and found this thread. I'm curious how honymand scarified them, as they seem to have had some success. Abrasive, kinetic, chemical, etc? Beyond that, I was thinking of a 1-week refrigerator stratification in a ziplock bag containing a piece of paper towel, lightly dampened by a mild 1% hydrogen peroxide solution, with the seeds placed on one side of the towel so that they're visible and in contact with both the moist towel and the air in the bag. I would then take the bag out and keep it in a dark place until roots become visible in the bag. The bag will be checked periodically for germinated seeds, and whenever one is found, it would then be laid apon the top of a mixture of approximately 40% peat, 40% composted manure, and 20% loose fill vermiculite with time-release fertilizer in seed trays. An additional half centimeter of soil would be laid upon it, and the plants watered from underneath. The plants would then be grown indoors in my LED grow room until they look sturdy enough to be gradually introduced to the outdoors. I'd probably also have some seeds undergo slightly modified versions of the above process, just in case I do something wrong.

Does this sound like a reasonable approach? Also, any scarification tips would be recommended.

Thuja occidentalis seed, I have been told, require a surprisingly high temp. of something like 85 F. to germinate. I don't know if this holds true for its western cousin, but just thought I'd add this to the discussion.

This bit of info I obtained both by reading silvics info supplied by the Forest Service, and in a discussion with the DNR Forester who is assigned to the area where my land is. He told me that most of the "cedar" stands present in this part of Wisconsin got their start following forest fires brought on by drought conditions in the 1930's dustbowl years. Evidently, it was the combo of exposed mineral soil and the charred wood and ashes, with their dark color, that aided this species in colonizing the newly fire-cleared sites. I find this sort of thing to be yet another example of the wonders of nature: Here you have a tree which for me, exemplifies the cool, northern forest..getting its start courtesy of fire. Now, clearly, the presence of so many seedlings and small trees of this species of much more recent vintage tells me that this is not the only way for seedlings to get started. But even here, many of the most concentrated areas where Thuja o. seedlings are found on my land are directly adjacent to, and to the south of, existing more mature stands. Warm spots for sure.

Sorry for the thread hijack. I really do enjoy talking about this stuff!

+oM

Thuja plicata regenerates well on its own in Britain, so the seeds don't need high temperatures to germinate. Don't know what 85F is, but I'd guess 10 to 15°C is plenty.

For soil, best to go something with a high mineral content; definitely not a peat-manure mix, that wouldn't be at all suitable.

Resin

My precise procedure: scarify by 24hour soak in temperate water (around +25C). Sow half. Of these approx 25% germinated.

The other half stratified by 1 week at +5C on a wet napkin in darkess. None of the stratified ones germinated, so I will not recommend the full procedure.

Sowing of all seeds on wet mineral rich soil (cactus soil). Germination happened between 1 and 3 weeks after sowing.

Now I have 3 seedlings left, all of which approx 3 cm high with 10-20 juvenile needles and no cotyledons. 1 is fresh green and looks good. Another is brownish and does not look so good. The last one is very brown, but does not look completely dead yet. Gowing to take them outside soon...

/Hans Olav

For soil, best to go something with a high mineral content; definitely not a peat-manure mix, that wouldn't be at all suitable.

That's odd. I thought their natural habitat was poorly-drained organic soils. It even grows in muskeg (basically, waterlogged peat). So I'm surprised to hear that they'd like a high mineral content.

If that is the case, I'd probably significantly up the non-horticultural vermiculite content. I really love that stuff. Dirt cheap and much more aerated than horticultural vermiculite (although it doesn't retain water as well).

The other half stratified by 1 week at +5C on a wet napkin in darkess. None of the stratified ones germinated, so I will not recommend the full procedure.

That's very interesting to hear. I wonder why? How wet was the napkin? And were the seeds bagged?

When you mentioned scarification, I assumed that you meant physically abrading the seed coat in some way or another.

"That's odd. I thought their natural habitat was poorly-drained organic soils. It even grows in muskeg (basically, waterlogged peat). So I'm surprised to hear that they'd like a high mineral content"

They will grow in muskeg, but they succeed there because they tolerate it better than other trees; it isn't the ideal conditions for them. Also muskeg is very low fertility, not at all like rich manure teeming in microbes and fungi which would rapidly infect and kill off the Thuja seedlings. I'd suggest a mix of your vermiculite with composted conifer leaf litter (composted pine needles or similar) or pulverised bark.

One other thing to watch out for, is Didymascella thujina leaf blight on the Thuja seedlings; this could be a problem if there are other mature Thuja nearby.

Resin

Thanks for the tip; I'll lower the compost percent. I don't have any composted conifer leaf litter, though, but I'll compensate.

No Thuja nearby, and I'll peroxide the seeds just in case there's any spores on them from collection. Thanks!

For what it's worth, so far, I've had four germinations (out of ten seeds) from using the paper towl/baggie method using pure water with no presoak, and no germinations from any of the other bags (those with water or peroxide presoaks and those with peroxide in the bag)

Still need more time to fully assess the others, though, including the stratified seeds, which only came out of the fridge last weekend. Also, I accidentally killed at least one of my seedlings taking it out of the bag -- I misestimated how much the root had attached to the paper towel and tried to just lift the seed off. Oh well. But on the upside, at least one of the germinated seeds has now pushed up through the soil, and is thus officially a seedling! :)

Out of curiosity -- would anyone be interested in some Thuja plicata seeds or seedlings? As mentioned, I have more seeds than I know what to do with, and for those who don't want to grow their own from scratch, I'd be happy to raise some to whatever height you'd like.

As a followup: I think I've pretty conclusively shown that peroxide is a bad thing for Thuja plicata. Not a single peroxide seed germinated, while about 40% of all others (stratified or not) germinated.

For anyone who runs into this thread at a later date: since I have so many seeds and don't want them to go to waste, I'm germinating and growing a lot of extra trees, so if anyone ever wants some, just let me know (meQme@daughtersoftiQresias.orQg -- remove Qs to despammify).

Hans Olav,

I'm also very curious if that Thujopsis dol. 'Cristata'
that Torreya 2006 mentioned is growing in your country.