Notes on Juniperus chinesis from seed

Wires_Guy_wires

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Since there's not much info out there on growing junipers from seed, I figured it might be handy to some people.
Other junipers I'm growing from seed behave almost the same, with phoenicea var. Turbinata as the main exception. I think these notes can apply to scopulorum, ERC and monosperma as well.

Germination
Some of my chinensis seeds required a cold dormancy, others did not. This might be related to seller storage conditions; I ordered mine from ebay from various sources.
I soaked the seeds in tapwater with a dash of peroxide for 24-48 hours.
Floaters were removed and sinkers were dropped in potting soil during fall.
Potting soil + sand (50/50) has proven to be the best germination medium. Sphagnum, inorganics etc did not work as well.

The seeds that didn't need cold dormancy germinated within 2-6 weeks pretty consistently.

Foliage
The first two leaves are different than the rest; ovulate, pointy and in a pair, but soft. They stay on for about a year.
Juvenile foliage is needled, sharp and follows a less consistent pattern.
Scale foliage starts forming after almost a year after germination, mostly as two-dimensional fronds. After another year it starts growing more three dimensional like we know from adult foliage.
Purple hues are common in colder areas, but they can be a sign of restricted sap flow or root related issues. Keep temperature in mind when diagnosing issues.

Soil
I found potting soil + sand to be the best soil for seedlings for at least the first year. After that, inorganics are fine. I do have to note that akadama suuuuuucks for junipers.
How much does it suck? Is a 60% difference in gowth sucky enough for you?
Juvenile junipers seem to be fine standing in muck, also in more dry soils. One notable observation is that there's a 100% dropout rate in full soil after prolonged summer heat, and just 5% dropout rate in mud, even after winter. Too wet seems to have a higher survival rate than too dry. For adult plants, it seems to be the opposite.

Patterns
Trunk -
I found that when growing healthy, seedlings gain around 3mm of girth a year, after the first year this seems to speed up.
Height - After a full year of growth, they measure around 5-10cm. After the second year, expect tyem to reach at least double that. Height growth seems pretty consistent and seems to be strongly related to the amount of foliage; more foliage = more growth.
Cutting back - You can cut back juvenile junipers to just above the first set of leafs, they will regrow from there. Further up is the same, below the first node is certain death.
Roots - Roots can be worked from 3 months of age. Any sooner and there's just a taproot and you might kill it. Rootwork up to at least 2 years of age can be done pretty radically.

That's it for now. I'll continue this thread later today.
 

Wires_Guy_wires

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2.5 years of growth. The foliage is changing from two dimensional symmetrical to three dimensional in the tips.

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2.5 years of growth in akadama. Only two out of the thirty I have sitting in akadama show growth comparable to regular potting soil.

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Terrible messy picture. But the one on the upper right hand side has done the "worst" in potting soil. Compared to akadama, that's roughly a 300% size difference. In favor of the potting soil.

One thing that's usually related to slow growth, is compact growth. I'm not seeing notable differences between akadama and other media as far as compaction goes. The ones in not-akadama soils seem to have similar internode length, but since they grow taller branches, they look leggier in the pictures. But I'm more comfortable cutting back the non-akadama ones.
 

Wires_Guy_wires

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Anyone in for a good laugh?
Well, I am. I kept wondering why the foliage of the plants in the pictures didn't look a whole lot like the junipers I own, and why they were so fast on making adult foliage.
Well, if you get your juniper seeds from China, you're going to get china'd.
They're thuja! Thu bad.

My sincere apologies to anyone I misled about these. It was all fake news. I take responsibility for it.
I'll be getting some actual juniperus chinensis seeds in a while for a retry.

Notes still are worth it though, they're not based on these thuja's alone, but on all of my junipers from seed, which still outnumber the thuja's. But it still sucks. Because I'm not a fan of thuja.
 

W3rk

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Anyone in for a good laugh?
Well, I am. I kept wondering why the foliage of the plants in the pictures didn't look a whole lot like the junipers I own, and why they were so fast on making adult foliage.
Well, if you get your juniper seeds from China, you're going to get china'd.
They're thuja! Thu bad.

My sincere apologies to anyone I misled about these. It was all fake news. I take responsibility for it.
I'll be getting some actual juniperus chinensis seeds in a while for a retry.

Notes still are worth it though, they're not based on these thuja's alone, but on all of my junipers from seed, which still outnumber the thuja's. But it still sucks. Because I'm not a fan of thuja.
lol you "got China'd" - sorry Wires, but thanks for the update and owning it. I have a small handful of Thuja seeds from my neighborhood that I'll be trying to grow this spring. Along with a nice pile of various collected Juniper seeds that have been stratifying in my fridge. So both species are relevant :)
 
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