DCO Storage/Stratification vs Vernalization

[MilkweedManiac]

Giving this a try for the first time and received my order of acorns today.

I read the thread on this topic, but wasn’t able to find out whether or not they could be held in ziplock with no medium until I was ready to stratify.

I’m having a bit of paralysis by analysis, so seeking some tips from those experienced.

Question 1 - How long is it safe to hold them in the ziplock bag (with NO medium) while in the refrigerator drawer? The bag is currently sealed and I see plenty of moisture droplets on the inside of the bag.

Question 2 - If I want to put these under grow lights in Mid-January, should I begin the stratification process now? Which method is recommended? Putting them in my rootmakers now and refrigerating would be a tough proposition because I have too many acorns to fit them all in the fridge that way.

Would a Tupperware with moist pro mix be ok for three months in the refrigerator with about 60-80 acorns?

Thoughts appreciated.


MM

 

[yoderjac]

It has been a few years since I messed with them so I can't remember all the details off the top of my head. Here is a thread that was started on the old QDMA forum by a guy who deals with them. There is some good information on that thread: http://habitat-talk.com/index.php?t...-from-seed-transferred-from-qdma-forums.5721/

Thanks,

Jack

 

[finahol]

My experiences with DCO acorns here in Michigan zone 5-6 depending.
I purchased DCO acorns from Blitz (Nebraska IIRC) the last 2 years. First year i tried to follow their instructions to the letter as far as planting in rm-18's and placing them in the garden under mulch and loosely covering with hardware cloth to discourage the critters. Held a few back in the fridge in a zip top with barely damp paper towel for moisture retention. The acorns planted in rm's were a dismal failure as the nuts were pilfered by rodents 100%. They are persistent and sneaky. the nuts in the fridge were about 80% successful germinating in spring but when I direct planted them out in spring they were 100% dug up and eaten also even when covered with small squares of hardware cloth. last year I was only able to purchase limited amount from blitz as conditions weren't great for a large harvest. I planted 36 in rm-18's and covered tightly with 1/4" HW cloth and confidently placed them under marsh hay for winter thinking I had it figured out. Kept about 30 in bottom of fridge in a bag with damp paper towel for back-up. In spring i expected to find 30 or so seedlings happily germinating in the rm's but to my dissapointment all had rotted. Not alot of snow cover last year and the moisture must have been too high with frequent thaws and refreezing. Had good success starting refrigerated acorns in deepot type 10"deep plug type pots in Feb. the DCO's dont seem to be real early germinators like white oaks and bur oaks. In May transplanted some into 1 gal rm's and planted some plugs directly into good damp soil at hunting property. As you can guess shortly after planting into nice damp soil with some shade protection we soon went into dry mode. They have struggled but most have survived and I will find out next year if they will survive winter. As with most species oaks in my experience they are slower to get going than the hybrids I am working with. This year i discovered some local DCO that i was able to harvest about 150 nuts from on sept 8th that i have high hopes for as they are a local source that seem to be thriving. Went back on sept 20 and they were totally gone. Short window for ripening and nut fall. Sorry for the long post, but the gist is that for me at least they seem to be easier to control with stratifying in the fridge in a bag with light moisture for about 90 days then planting out. I will try direct planting this next spring as i hope they can develop a better root system in the ground as opposed to starting in pots. I think the key may be minimal ground disturbance so as not to put a flag out for the mice and ground squirrels. Had much better luck this year with other oaks by simply pushing a hand shovel about 2" into the ground and levering up a bit to place the nut in the ground then covering up without making much of a disturbance. Good luck. DCO's i have found growing wild here seem to be in very open areas without any overhead cover. Fence lines and roadside ditches with no large trees shading them out.

 

[finahol]

Watch them for mold which would indicate too much moisture. When they start to push a radicle they are ready to bring out into the warmth and plant. Seems to be be best on their sides. Dont over water but dont let them completely dry out. It's a tricky balancing act.

 

[MilkweedManiac]

Watch them for mold which would indicate too much moisture. When they start to push a radicle they are ready to bring out into the warmth and plant. Seems to be be best on their sides. Dont over water but dont let them completely dry out. It's a tricky balancing act.

So helpful, I can't thank you enough. The moist towel seems like a better idea to me simply because damp pro mix has given me some moldy chestnuts before. Using paper towel method, did you find the acorns started pushing out radicals at all or did they suspend activity until you unpacked them 90 days later?

 

[finahol]

As Yoderjac posted there is a ton of good info in blitz's thread. It just didn't all work for me so i have adapted due to differences in my local climate. By the way, i had trouble locating the media blitz suggested but i have found pro-mix HP to work pretty well for my purposes. I sometimes add some fine pine bark when moving up to 1 gal pots but havent noticed any real difference in how the seedlings react. Chestnuts are more picky about watering. I place them out after hardening off in about june but they cant take full sun for quite a while without burning the leaves. My seedlings receive water from my lawn irrigation mostly every other day and seem to do just fine. Hybrid oaks are about 2' tall in a season. DCO's and Chinkapins only 6"- 9" so far.

 

[yoderjac]

I found the thread with the pics from when I tried them along with hazelnuts. It might have some good info as well: http://habitat-talk.com/index.php?threads/dcos-and-hazelnuts.5600/

Thanks,

Jack

 

[finahol]

The paper towel treatment seems easier to control for me. i check them about every 2 weeks. when it's dry i wet it and squeeze it. I dont add any holes to bag but some do. With chestnuts I usually use peat moss but get some mold. I just rinse it off if not too bad and it doesn't seem to hurt them much. The acorns with the paper towel method generally push radicles on their own time, but don't grow too fast so no hurry. You can see when they start to swell and pointy end starts to crack open and it's GAME ON! Try to keep them laying flat and always orient same direction (label up). otherwise gravity will take over and the radicles will twist and turn.

 

[finahol]

Last note. I keep them in the crisper drawer of the beer fridge which is set to 28-30 degrees. sometimes they will freeze just slightly but the beer is always perfect and it doesn't seem to hurt the nuts.

 

[MilkweedManiac]

You really helped, I truly appreciate. I had scoured the Blitz thread for a few days leading up to now. Such a thorough thread of helpful information. But I still wasn’t quite sure (or didn’t see it mentioned) if I could hold them in ziplock using the paper towel method until ready to grow indoors in January. I was concerned the acorns might begin to decay or breakdown since they are so small. Moisture will be key I’m sure.

My plan is to use Pro Mix HP (the same kind I used for my Chestnut’s). It seems very high quality.

 

[yoderjac]

This is not DCO specific but here is my take on nuts that require cold stratification:

Cold stratification requires a particular temperature range (above freezing but generally less than 40 degrees) and a particular level of moisture. As the moisture level drops, the cold stratification process slows. So, generally, if you keep the well hydrated fresh nuts in a plastic bag in the crisper with no added moisture, they kind of go into suspended animation. If you add moisture later and keep them cold, the stratification process will resume. If the moisture content is too high, it promotes the conditions for mold to grow. Nuts that are high in carbs seem to be more susceptible to mold. However, mold does not spontaneously appear. The nuts need to be exposed to mold spores. It is true that mold spores are in the air and you can't completely keep them protected, but warm and moist are the conditions that promote it the most. So, when collecting nuts, it is much better to get them from the tree than pick them up from the ground. While washing off the nuts off with clean cold running water is a good practice, it won't eliminate mold spores and neither with a bleach solution. I don't know about acorns, but I find bleach reacts with the chestnut shell and can be problematic. Soaking nuts for a few hours before cold storage is also a good practice. If the kernel dries out, the nut will die and won't germinate. So, if you put them in a plastic bag to suspend them and they are not fully hydrated, you do risk losing some. Using long fiber sphagnum as a medium for cold stratification is generally better than a paper towel. They can both be properly dampened to hold the right moisture level, but sphagnum has some anti-fungal properties that may help with mold control a bit more.

Most nuts that require cold stratification want to see 60 to 90 days. Wayne and I did some informal testing one year with chestnuts. We handled our nuts the same except he cold stratified his for 90 days and I did 60 days. I got pretty good germination, about 75%, but he got over 90%. I suspect this hold true for other nuts as well but I have not tested others like this.

Best of luck,

Jack

 

[MilkweedManiac]

You guys are awesome. Thanks so much. I will report my progress, whether successful or not. Excited.