How should I go about seperating large 4 inch pregnant onions?

I have a 3/4 yard planter on wheels in my living room in which I planted pregnant onions in along with a few aloes, a bunch of kalonchoe and two 5 avocado trees now 5 and 6ft tall. This has worked great until the last few months, one of my avocado trees appears to be dying, this may be due to having 5 pregnant onions right beside it. I like the idea of having the two trees in this planter, the pregnant onions are awesome looking, but the six foot leaves hanging all over the floor kind of get in the way and get walked on by the kids.
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I think the best solution is to remove the large pregnant onion plants and pot them individually and allow them to hang from the loft into the living room, this would remove the trouble with people walking on the leaves and may improve the situation for the dying avocado tree.
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I do not know how tolerant these plants are to root damage, I imagine that as long as I get some root they will be alright, but I really don't know this. What percentage of root should I be trying for? Some of these bulbs are no more than 1/2 inch away from a 5ft avocado tree and so I have to be carefull not to damage the tree much either.
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Anyone have any advice.... I am all ears at the moment....

I will attempt a picture for the third time, don't get yer hopes up...

[URL=http://s1167.photobucket.com/user/WealthyMTGuardian/media/preg%20o%202.jpg.html][IMG]http://i1167.photobucket.com/albums/q630/WealthyMTGuardian/preg%20o%202.jpg[/IMG][/URL]

I give up... no pics... use your imagination...

Lets try it this way maybe...

got the pic that time.
I haven't done this. I have grown pregnant onions.
As long as you have some roots, I think they'll be pretty resilient. Might try not to damage any of the bottom of the bulb where roots come out. So cutting a small hole around the onion, to leave short roots, and not cut too much avocado root, sounds to me a good idea. Unless someone can be more specific.

Well I got brave this weekend and went ahead and transplanted the pregnant onions.. I went ahead and used the method that I use on most of my baby aloe plants. I started a ways away from the plant mass and worked my hand down into the soil to about 10 inches deep and then came up under the root mass. I kept loosening the soil around the roots until I had a couple outer bulbs fairly loose. I followed the roots out as far as I could, gently breaking them free of soil and other roots. I then cut the roots where they were entangled into the main root mass.
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This was not the easiest feat and there were a couple onions that did not have a lot of root ball attached to them. I did find many young bulbs attached to the large pregnant onion bulbs under the soil, many, many dozens of them.
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I learned one thing that I had not expected, though I should have expected it. When the large bulbs split into two bulbs they still have a common base and share the same root mass (think garlic cloves with the common base and roots). This makes seperating them without damage to the bulb a bit tougher, I loosed the roots and soil under the entire main mass of large bulbs and then pulled two large bulbs apart enough to cut between them through the common base material and seperate them out. This gave each piece some of the original root mass.
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It is too soon to know for sure exactly how well this went, it will take some time for them to do much of anything that I can see in the new container.
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I noticed as I was working through all of this that there were no other plant roots within the area of the pregnant onion roots, this is unusual and unexpected. This planter has many, many plants in close proximity. There was an avocado tree within 1/2 to 3/4 inch of some of these pregnant onion bulbs on the back side, yet there were no intervening roots from the tree or any of the other plants that I could tell. I had originally decided to move the pregnant onions in the first place, due to the fact that the Avocado tree was dying and 24 inches away in the same soil and setup I had another avocado tree going banannas growing like a weed. It seemed possible that the proximity of the pregnant onions may be responsible. I am beginning to wonder if the pregnant onion puts something into the soil around it's roots that is damaging to othger plants roots a natural means of controlling competition, hence the dying avocado tree and lack of non pregnant onion roots in the region of the plants. If this is the case, then it would be important to note this if one ever mixes this plant with other plants in a planter. I now have them in their own planter, well I have a few kalonchoe that broke off while working with all this, stabbed in there at moment. I will give it some time and come back and post what all I have been able to learn.
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A picture of the pregnant onions in their new container and new position in the house, wow these grow long leaves, every leaf has been cut at least a small amount and some are still 7 feet long...

Interesting, I am able to reply to my own post but to reply to anything else on this requires a subscription, I don't remember seeing that anywhere before joining this site. I guess the money from your advertising isn't enough, well thanks but not interested, I will go find another site to join. I will try to delete my account, if I cannot I would appreciate it if you guys would, thanks...

well drat.
Sorry to see you go. I have been following your thread, and you seem like just the sort of person I like having on here. Some forum,s are only for paying members, I guess this one accepts all.

Paying members don't get the advertising but there are some forums you should be able to reply without a subscription. This being one of them..,,,can you reply to this post and see if it works? Im with Pistil, I'd like to see you stay.