Juniper seed germination

[JuniperMasterRace]

I am in the process of stratifying Utah Juniper, California Juniper, and Temple Juniper seeds. I scarified the seeds rubbing them with sand paper and then soaking them in hot water (not boiling) for 8 hours. 90 day warm stratification followed by 90 day cold stratification for the California and Utah juniper seeds and 30 day warm stratification followed by 60 day cold stratification for the temple juniper seeds. After this, I guess I just plant outside and grow like a normal seed in an outdoor greenhouse.

I am going to attempt some more juniper seed germination soon. Anyone with experience with this please let me know if you have any insight.

 

[Leo in N E Illinois]

The hot water dissolves some of the resins coating the seed of junipers, probably needs to be done for all species.

Most, if not all junipers require both warm and cold stratification. As a adaptive strategy, junipers tend to have a seed bank in the soil, even after the first cycle of warm and cold stratification not all the seeds will germinate that year. A portion will germinate the second or third years, a small few might even wait until the 4th year.

If you don't want the hassle, just plant your flat of juniper seeds, label it well so that you will be able to read what is in there 3 years down the road. Set it outside and forget about it, let nature, the cycles of winter spring summer fall do the stratifying for you. Once a year, pull (scoop out) new seedlings and transplant them to their own pots, just leave the rest of the flat as is to be able to see what comes up the next year.

 

[Wires_Guy_wires]

I've had good luck with cold stratification only.

 

[Leo in N E Illinois]

Seed that is fresh, and has not dries below some % moisture level, might only need cold stratification. If your seed was purchased, it was probably allowed to dry, it will need the warm and cold stratification. I don't know what the critical moisture level is, or I would tell you.

 

[Wires_Guy_wires]

Leo, I've used both fresh and dried seeds. I believe that because juniper berries take a bit more than a year to mature, drying isn't always needed.
ERC, scopulorum and osteospermum came from the web, those were dried. Germinated pretty fast with cold stratification.
Phoenicea var turbinata didn't need drying, from fresh seed with a short cold strat.
J. Chinensis didn't need any treatment at all other than soaking, those were dried.
Berries I've collected did OK (30-60% germination) when used fresh. What affected germination the most was the ripeness of the berries, they need to be 'well done'.

 

[eryk2kartman]

I treid Juniperus Chinensis 2 years ago, 180 days of cold stratification, nothing germinated at all (planted 500 of them) left them outside till this year spring, my hopes arent high but lets see if anything germinates. Seeds were dried when started stratification.

 

[JuniperMasterRace]

I've had good luck with cold stratification only.

For cold stratification, I just leave them in my vegetable drawer in my refrigerator. I am not sure what the exact temperature is needed and if I need to make my fridge colder or warmer.

I have some sugar pine seeds I harvested from pine cones on a hike to Mt. Baldy and I have left those in my freezer and they have been in there for the last 3 months. I'm not sure how to stratify them properly, I just logically thought about what conditions they would be subjected to on the mountain elevation where I picked them up at and thought to leave them in there until winter is over and then warm stratify them and plant them.

 

[Wires_Guy_wires]

There are no exact temperatures fortunately! Somewhere below 10 degrees C (most fridges are set to 5C in Europe) should be fine.

When stratification doesn't work well, there's always the option of using peroxide, which is at the top of the germination cascade, or dilute acetic acid which is somewhere down the line. If all else fails, gibberilic acids can be used in very(!) dilute amounts. But too much of the gibberilins and they might never germinate at all. Dwarfism van be caused by the stuff too, which sucks because it also slows growth.
Some plants need a wet-dry cycle to activate growth as well. I found that the more tropical oriented junipers like this; they germinate after a short soil dessication. Or sometimes even fire (which is easy to emulate, especially if you know someone who smokes, just borrow their ashtray and throw some buts on the soil).

In very extreme cases, removing the husk entirely and putting the embryo in a liquid medium can do the trick.. But that's quite an expensive and tedious procedure and you'd need a lab for it. I've done it a few hundred times and I don't recommend it!

 

[JuniperMasterRace]

I treid Juniperus Chinensis 2 years ago, 180 days of cold stratification, nothing germinated at all (planted 500 of them) left them outside till this year spring, my hopes arent high but lets see if anything germinates. Seeds were dried when started stratification.

any reason as to why they didn't work? I am hoping that's not my case.

The hot water dissolves some of the resins coating the seed of junipers, probably needs to be done for all species.

Most, if not all junipers require both warm and cold stratification. As a adaptive strategy, junipers tend to have a seed bank in the soil, even after the first cycle of warm and cold stratification not all the seeds will germinate that year. A portion will germinate the second or third years, a small few might even wait until the 4th year.

If you don't want the hassle, just plant your flat of juniper seeds, label it well so that you will be able to read what is in there 3 years down the road. Set it outside and forget about it, let nature, the cycles of winter spring summer fall do the stratifying for you. Once a year, pull (scoop out) new seedlings and transplant them to their own pots, just leave the rest of the flat as is to be able to see what comes up the next year.

So I should I expect to wait a couple of years for this seed project to show results?

 

[JuniperMasterRace]

There are no exact temperatures fortunately! Somewhere below 10 degrees C (most fridges are set to 5C in Europe) should be fine.

When stratification doesn't work well, there's always the option of using peroxide, which is at the top of the germination cascade, or dilute acetic acid which is somewhere down the line. If all else fails, gibberilic acids can be used in very(!) dilute amounts. But too much of the gibberilins and they might never germinate at all. Dwarfism van be caused by the stuff too, which sucks because it also slows growth.
Some plants need a wet-dry cycle to activate growth as well. I found that the more tropical oriented junipers like this; they germinate after a short soil dessication. Or sometimes even fire (which is easy to emulate, especially if you know someone who smokes, just borrow their ashtray and throw some buts on the soil).

In very extreme cases, removing the husk entirely and putting the embryo in a liquid medium can do the trick.. But that's quite an expensive and tedious procedure and you'd need a lab for it. I've done it a few hundred times and I don't recommend it!

Any books you could recommend on seed germination science? Specifically junipers (hence my name)

 

[Wires_Guy_wires]

Any books you could recommend on seed germination science? Specifically junipers (hence my name)

Not specifically, no. Most books I own are about vegetative multiplication. The only plants that are popular AND hard to grow from seed are orchids, all the rest isn't even mentioned in most books.
Scientific literature about junipers (other than population analysis, environmental impact and chemical substances) is scarce or non existant.
I made a post about my notes on Chinese junipers from seed. It's linked to this thread as a 'similar thread'.

I can recommend Plant physiology by Taiz. There's an outdated version somewhere on the web as a pdf. Some stuff has been scientifically debated and is not that accurate anymore (like strictly polar transport of auxins, they can be produced locally too!) but the basics are solid, real solid. From a plant biology standpoint, it's basically the bible.

 

[0soyoung]

Any books you could recommend on seed germination science? Specifically junipers (hence my name)

Deno's book "Seed Germination Theory and Practice" and supplements are in the BNut Resources.

 

[eryk2kartman]

any reason as to why they didn't work? I am hoping that's not my case.

So I should I expect to wait a couple of years for this seed project to show results?

I don't really know why they didn't germinate, they looked moist and swallowed in the fridge, maybe they got dried out somehow when they get planted in the tray or seeds were old,
They are still outside in the tray, we will see in the next month or 2 if there is any progress.

 

[sorce]

Welcome to Crazy!

Sorce

 

[JuniperMasterRace]

Thanks for the help, I'll post my full set up when I begin germinating about 12 different junipers this month!

 

[Viridian Bonsai]

Any updates on your seeds?

 

[cmeg1]

Yes any updates? I have some Juniperis Chinensis stratifying for the CO2 fertilize set up. I wanna see what happens here.

This could be very nice ….Evergreen seem to benefit from the LED lights and the CO2 fertilization with the 18 hour light cycles and everything

 

[MaciekA]

Yes any updates? I have some Juniperis Chinensis stratifying for the CO2 fertilize set up. I wanna see what happens here.

This could be very nice ….Evergreen seem to benefit from the LED lights and the CO2 fertilization with the 18 hour light cycles and everything

Surprised to hear you're not cloning itoigawa or kishu or something with known-good characteristics. Hoping to get a roll of the die instead?

 

[Wires_Guy_wires]

Yes any updates? I have some Juniperis Chinensis stratifying for the CO2 fertilize set up. I wanna see what happens here.

This could be very nice ….Evergreen seem to benefit from the LED lights and the CO2 fertilization with the 18 hour light cycles and everything

You might want to try a window sill instead just to see what pops up. I've been getting consistently low germination rates with chinensis.
It might be a waste of space and electricity to keep them in a growroom while they germinate.

 

[cmeg1]

Surprised to hear you're not cloning itoigawa or kishu or something with known-good characteristics. Hoping to get a roll of the die instead?

Not sure I avoided Juniper for years for some reason from all the mallsai I’ve seen, but it would probably grow quicker and everything in the CO2 tent.