I stratified a few apricot seeds in mid summer and started growing them in early August. I grew them outside in pots through October and have been growing in my basement grow room ever since. I’m thinking of keeping one or two going all year under lights, but I’d like to have the others go dormant so they can wake up naturally with everything else in the spring. Has anyone done this before? Any suggestions on how to do this without shocking or killing the young plants? I feel like the five months of growth they’ve had should be enough, but curious to hear opinions.
You can continue to grow them under artificial lights and they will not go dormant until Fall 2020.
Or,
trim the leaves off and put them where temps are above 28 F or (32 F but only if soft green tissue at 32 F or above) because 28 F is when root damage occurs; after 3-weeks of ‘cold’ temperatures they are ready for sleep. 3-weeks is the magic # for any/all hardwoods to begin their dormancy.
And there are in-betweens as you’ll understand: you can force something to go dormant but wake it up multiple times to put several-many spurts of growth in a single year. That’s the example I was thinking of.
In one-year a friend grows a pawpaw seedling from several cycles of putting into dormancy and removing and putting growth on them and gains a 3/16ths caliper 14-18" tall a lot of the time. I didn’t know that’s how he was able to get a pawpaw that size in one year but I had assumed it was his 10" mini-treepots making all the difference + lots of fertilizer, but another fella told me he was getting several spurts of growth per year. I could only grow a 5-6" pawpaw from 14" x 2.7" Deepots this year.
I’m intrigued. I’m doing basically the same thing with my Jack-in-the-pulpit and Solomon’s seal seeds. How long of a dormancy do you think would be adequate before you wake tree seedlings up? I suppose the answer is “it depends on the species!”
3-weeks, naturally/of course. I’ve been grafting 17-years so I know all this stuff. The man that told me all this was a grafter for more than 50-years. He told me my wax recipe for greenhouse grafting which I modified by adding beeswax to better suit outdoor grafting, etc. He told me how summer roots kick back on and when so I would know when I could graft (Japanese maples and Ginkgo back then) and he told me not to graft Beech trees like how he told me to do the others cause they wouldn’t ever work. Since he’s no longer alive I can only assume from my own trials and tribulations now that maybe it’s because Beech is such a dense wood type that none dense wooded trees/hardwoods will work that way. So, I mean it goes on and on and on in my mind and in the pages of notes where I kept every little tidbit the guy told me. The theory is always going to be based upon “3-weeks”. Plants don’t know any differently when you tell them it’s time to wake up and when it’s time to go to sleep and as long as the requirements are met, you could cycle things perpetually because that’s how science tells us.
@barkslip Thanks for the response! While you were typing, I did some quick research and came to the following conclusion: CRFG lists a 400 chill hour minimum, so I suppose that would be a good place to start for pawpaw. 400/24 = 16 2/3 days. So, round it up to 21 days/3 weeks to be safe, on top of the 3 weeks to induce dormancy, for a total of 6 weeks. The chill hours part definitely sounds in line with you and your mentor’s experience. Would you consider the 3 weeks to be on top of the 3 to induce dormancy, or include that?
Edit: I’m getting things all out of order! I see your response below. Sorry!
Okay, I don’t even need to read the link. And since we’re talking in real time, I see what you mean. I hadn’t given that a though. Conifers and all deciduous (all I knew was 3-weeks and they could go dormant.) I wasn’t grafting ever based on chill hours. Ornamentals was my gig.
I’ll ask the guy growing the pawpaws what he does. Thanks, Jay.
Edit: I hear ya! I’m on a desktop. You’re probably on a phone, lol. I don’t/wouldn’t have any way of even knowing anyway. Talk to you later, Jay.
10-4 on all those 5 inch pawpaws….I have a bunch of them!
But, in 2018, I planted pawpaws in July. They came up in August and September.
A few of them made it through winter in 1 gallon containers outdoors in the elements.
You just have to gradually reduce temps…not go from 60 or 70 to zero…for that will definitely not work out well. But, the youthful age of the plants doesn’t mean they can’t be made to go dormant, and then come back in spring.
It requires some thinking, I understand. But moderately stiff wood has the cold-factor-“hardiness” it needs to switch gears FULL SPEED AHEAD and go right into winter. I’ve experienced it during life. I’ve seen landscape specimens and trees I’ve grafted that year decide to put on a shot of growth during August or Sept. and is “fully-green” going into winter. I think you understand there are fine lines at times and we have to play by the rules. To try to explain that simply is not easy coming right out of the gate, even if I had more information than I already had.
I talked with my friend, he puts his seed into strat. & meets strat; put the seed on heat; when they germinate he plants them and grows them until they stop on their own outside later that year. It couldn’t be any simpler. I asked him how long if he would speculate for us he could keep a pawpaw seedling growing and his answer was very simple… he said, once the last leaf produced and is brown in color, it’s over. He said, in his best estimate that a germinated pawpaw could be growth-driven for 9-10 months tops before it would produce that last brown leaf…
Everyone else may need to check Jay’s chill calculations if attempting to put a hardwood to sleep and wake it up again as early as possible to begin another completely new growth cycle (a full cycle.) That’s how I interpret this situation, now.
Obviously this is a great subject for more discussion.
Ah, OK. That sounds like what @forestandfarm does, and what I had originally planned on, just with an earlier start. I bet you could use the artificial dormancy in combination with the early start to get some jumbo-sized “2 year” seedlings in 15-18 months.
Talk to you later, Jay.