Bismarckia Nobilis Info and question

[D. Morrowii]

I was going to post up possibly some interesting information about my, finally successful Biz plantings but now Im also in need of some help. 
After several attempts at growing Bismarckia  from seed I finally got it to work which was very satisfying. I ended up planting a dozen of the strongest germinated seeds into some 16 inch tall tree pots. A couple of weeks later about half had strap leaves were popping up.  Then the squirrels found them and ripped out four of the seeds! Here is the part I thought was interesting. Even the ones that didn’t have a leaf coming out of the soil yet, survived the seed being ripped out. From all the reading I had done on the web it seems like root sensitivity is a consideration for these palms so I figured they were done for. However, all but one sprouted anyway and continue to grow for the last 3-4 weeks. Maybe this is common knowledge to the more experienced folks in the group but I was surprised to see it.
Now for the help. I figured I would take the screens I had put over the pots to protect them off and when I started inspecting the plants I noticed there were lots of roots extending from the bottoms of the tree pots.
 

So my question is do I need to re-pot these or is it too late? If I repot it seems like Ill have to go to a 5-7 gallon pot to keep the height.  Is pruning the roots an option? What should I do? 

[Fusca]

Not too late to repot if you're careful - that's some nice root growth!  Pretty amazing that so many seedlings survived being disconnected from the seed so young in life.  I had one of my bizzy seedlings grow a root through the screen I was using at the bottom to keep the medium in place and accidentally sliced the extended root off (about 1" ) while trying to repot it.  It survived just fine but it might have been slightly stunted.

[D. Morrowii]

Thanks @Fusca! So do you think I need to maintain that depth or should I try to put them in slightly shallower pots and carefully curve the roots? A 3 gal pot seems reasonable for the amount of root growth these have but the 3s I have are only 12” deep. 

[Billeb]

3 hours ago, D. Morrowii said:

Thanks @Fusca! So do you think I need to maintain that depth or should I try to put them in slightly shallower pots and carefully curve the roots? A 3 gal pot seems reasonable for the amount of root growth these have but the 3s I have are only 12” deep. 

If they were mine I’d probably put them in 5’s as not too disturb any more of the roots trying to fit them in a shallower pot. I’d recommend using a screen material at the bottom of the pot so the roots can’t come out of the bottom and have to deal with this same situation again. Good luck. 
-dale

[D. Morrowii]

Yeah probably best not to beat up the roots any more than I already have. I have a couple empty 5s here Ill try to transfer a couple today. I like the screen idea I may be able to use that to extend the use of these tree pots a bit. Thanks for chiming in Dale.

Dean

[Fusca]

I was using metal window screen material and the roots still managed to get through!  I agree, 5-gal would be the best choice.

[Merlyn]

Is there a reason to repot from the existing Steuwe 6x6x16 pots?  I haven't grown Bismarckia from seedlings, but it seems risky to move them from essentially a 1.7 gallon pot up to a 5g pot at this point.  They probably haven't grown enough roots to come close to filling out the soil, so it'll all fall apart when you try to transplant them.  I'd think that would cause more root disturbance than just leaving them as is until they go palmate.  If the roots have grown into a complete mass that fills the pot, then you can slide the whole thing out (except for a couple of escapee roots) and directly into a 5g pot with practically zero root disturbance.

[sonoranfans]

yeah I agree those bizzies wont have lots of roots yet.  You may see them at the bottom but they haven't filled the container enough to handle easily.  If you create an airspace under them, the roots will not go far as here is no dirt or moisture to grow into  When they have 3-4 strap leaves they will be ready for transplant, and then I would go into a 10 or 15 gallon tall pot.  I'd trim off the long root and raise them so there is air under them,  Trimming that root may kill it but as is that can happen if you try to transplant too.  

[D. Morrowii]

6 hours ago, Fusca said:

I was using metal window screen material and the roots still managed to get through!  I agree, 5-gal would be the best choice.

Yeah I had the same thought then I switched to this nylon mesh I had with real fine openings. Time will tell. 

3 hours ago, Merlyn said:

Is there a reason to repot from the existing Steuwe 6x6x16 pots?  I haven't grown Bismarckia from seedlings, but it seems risky to move them from essentially a 1.7 gallon pot up to a 5g pot at this point.  They probably haven't grown enough roots to come close to filling out the soil, so it'll all fall apart when you try to transplant them.  I'd think that would cause more root disturbance than just leaving them as is until they go palmate.  If the roots have grown into a complete mass that fills the pot, then you can slide the whole thing out (except for a couple of escapee roots) and directly into a 5g pot with practically zero root disturbance.

So to your point, I was going to do a couple test re-pots and as I knocked the soil loose from the pot and slid the plant/soil “slug” out, the roots just sort of slithered back through the holes without breaking or anything. The soil mostly fell away and you're are correct there is basically just the one main tap root and it has some small regular offshoots. I ended up putting it all back in the treepot and carefully backfilled the soil around the roots the longest ones I just kind of coiled up in the pot. As mentioned above I put a small fragment of mesh in the bottom to help prevent roots from digging their way out. The fabric is like a sieve and water goes right through it. I will take your advise and raise these up so no dirt or water beneath the pots will attract roots! 

2 hours ago, sonoranfans said:

yeah I agree those bizzies wont have lots of roots yet.  You may see them at the bottom but they haven't filled the container enough to handle easily.  If you create an airspace under them, the roots will not go far as here is no dirt or moisture to grow into  When they have 3-4 strap leaves they will be ready for transplant, and then I would go into a 10 or 15 gallon tall pot.  I'd trim off the long root and raise them so there is air under them,  Trimming that root may kill it but as is that can happen if you try to transplant too.  

I think most will make it now in the pots as is and should be at the stage you mention in 6 months or so. If the weather is good then Ill transplant to a 10 or 15 like you suggested. 
 

Thanks very much for the help and comments everyone I do appreciate it!

 

Dean