Ideal Time to Transplant JRP/JBP Seedlings

(Tyrone Slothrop) #1

This is my first year propagating by seed – pine or otherwise. I had great germination, but I’m curious, can I transplant the seedlings at any time? Would right now be okay? Currently I have them all in a big cement mixing tub and intend to put them in individual pots. I live in Michigan and the growing season started about a month ago (or less).

Additionally, if one were to transplant them at this time of year (assuming this is an okay thing to do), would cutting the taproot be advisable?

Thanks ;-D

(Jonas Dupuich) #2

One of the first questions is whether or not you’re interested in making seedling cuttings (making cuttings of the seedlings to generate more roots). If the answer is yes, that’s a good opportunity to transplant the seedlings into individual containers.

If you’re not looking to make seedling cuttings, the next question is whether the seedlings can stay in the mixing tub through the growing season or if it makes more sense to separate them earlier. Leaving the seedlings together for a full season is fine, but the roots can become a tangled mess, especially if there isn’t a lot of soil for them. Also, if the seedlings are planted very close to each other, say 1" or less space between them, they can benefit from more space.

Seedlings can grow continuously the first year and repotting at any time can slow them down. I’d want to repot them sooner rather than later, at about the time with the immature needles are fully grown but before the trunk elongates further. The tap root can be cut at this time if desired, though additional care will be required to ensure the seedling doesn’t dry out.

Feel free to post a photo so we can see how far along the seedlings are.

(Tyrone Slothrop) #3


Thank you for replying in such detail!

With regards to seedling cuttings (I actually looked at your blog post on this earlier today), I do plan to do some cuttings and leave some as-is to test it out (I realize seeing the results of this will take a long time).

As for the placement of the seedlings in the tub, they’re not spaced out well, which is was prompted me to make the post. The crowding will have an adverse effect on the vigor of the seedlings and I intend to space them out. There’s an adequate amount of medium, but they’re too close to get good sun to all needles.

I’ll repot according to your suggestion (immature needles fully grown, prior to trunk elongating). I do intend to cut the taproots, but I’ll keep the seedlings under shade cloth (with misting as my work schedule allows) for a month or so, if that’s advisable.

I’ll post pictures of what I have so far when I get a chance (probably tomorrow, but who knows. lol)

Thanks again for your input! From my experience with bonsai blogs/internet bonsai research, you’re THE most helpful person I’ve met.

Take care,


(Shay Cohen) #4

Hello Jonas,
I am currently in the same stage of growing my first batch of JBP.
my question is, have you ever tried to cut only some of the tap root? maybe this way you could get a little of both natural look and a spread of smaller roots.I have no idea if that is even possible… might be totally wrong but asking first always helps :smile:
Thank you,

(Tyrone Slothrop) #5

No pictures but I thinned out the grouping of seeds and planted some individually or in clumps. Those I took out didn’t have more than the taproot. The transplanted seedlings are now in shade. I thinned them out enough to where they can grow in their current contained and be separated next year. This weekend I’m going to get many more pots (so many seeds sprouted!) and medium to begin some seedling cuttings.

(Jonas Dupuich) #6

Shay - yes, this is definitely possible:

I’ve tried it too. Not sure if there is a big advantage to cutting off all roots or simply cutting the tap root back to lateral roots, though it is a pretty natural compromise between the two extremes. Definitely worth a try.

For an unexpected approach, see more from Neil:

(Shay Cohen) #7

Between asking and receiving an answer I came across these two links already…
Thank you for the help!
I made some cutllings and some half cuts today. The picture is only of several of them.