I wanted to know if anyone here has ever root pruned there citrus before. When does it become necessary to do so?
Practically speaking, for containers, the short answer is -whenever your container is at the max possible size you want to handle, and you want the plant to put on new growth either for foliage or blossoms and fruit and it is root bound.
Here are things going on normally:
..The plant tries to grow into avilable rootspace.
..The plant tries to maintain balance of top and root size.
..Growing roots provide hormones for the top to grow.
..If you cut back the top too much, the roots will die back.
Abnormally, (we hope):
If tht plant gets rootrot the top may stagnate or die back, depending on when how much damage occured.
To keep the top from weakening or dieing back after root loss, top prunning may be needed.
Okay thanks for that info but how would you root prune. I have heard must of what you said above before. My Improved Meyer is quite large and I would like to only have to put it into one more larger pot. I don't mind removing old growing medium but I know at some point it will have to be root pruned. Before I water the tree, I ckeck the soil moisture on the surface of the pot and thru rhe drainage holes on the bottom. There is very little space for anything in the bottom of the pot. I mostly can feel the large roots and a small amount of bark. I plan on carting the tree out when temps are permanently above freezing and repotting it. Currently it is in a 12 inch wide and 18 inch long pot. I would like to get a pot about 2 feet wide and 18 inches deeps. I want that to e the last pot I buy, at least for the next 5-10 years. Maybe eventually I will be able to live somewhere warm enough and I can put it in the ground. Maybe I will have a greenhouse and it can have more room but not in my near future. I really enjoy this tree and it is adjusting well to its surroundings. I have to admit I was worried about all the negative feed back when it came to the Improved Meyer lemon. Seems like there are quite a few people who have had bad experiences with Meyers. I think part of my good fortune is because of the meer size of the tree and that is how I got it. I also have good natural lighting for it.
Andrew, I watched a garden show on tv a couple years ago. The host worked on a huge, container-grown citrus tree.
He removed the citrus from its pot, then cut/inserted in roots, (using a sharp knife) 1/3rd of its roots. He then placed the tree in the same container, adding fresh soil..Afterwards, he pruned 1/3rd of the trees' leaves. He was very firm about removing both top and bottom, saying a tree needs balance.
BTW, the citrus was standard, not a mini/dwarf.
After completion, the citrus tree looked fanastic.
I don't prune citrus branches, but I also don't have a 6'er..lol..unless you get the green house, I understand the need to reduce size.
Unless you have high ceilings, in a sunny room, I guess the best next thing is trimming..
If you end up pruning roots, be sure to trim top too. Toni
When you bare root it, you'll have a much better picture of what you'll be up against. Regardless of how large your tree is, if the roots are not spread throughout your "final size" container (and esp up to the outer pot edges) you're not required to prune. I would do some of it anyway rather than waiting to do it all during one year. Be sure to avoid exposing roots during the day heat, direct sunlight, and keep them misted during the process.
In general, you remove the thickest roots and trim back medium ones that are long without much sub-branching. They will subbranch near where you trimmed it.
When I buy a new citrus and put it into a fresh mix, I always detangle roots and organize them and prune the longest ones anyway. This makes it so much easier later. The detangling involves straightening out or removing any circling roots on the bottom or ones that go through the middle. In general you want them to fan outward, not downward. Roots that are wrapped tightly around larger ones (especially around the buried portion of the trunk) can be problematic as they grow -- I remove these also. But "organizing" doesn't mean eliminating, just moving them around to lay correctly on the side of the ball they originated from.
Only the thinnest roots take up water and nutrients. The thick ones take up the most space but only transmit the goodies from the fine roots. They also add support for standing in the container -- so you always want some. Anything thicker than a pencil or so starts taking up more room in your container but are not as much "bang for the buck" idea. So keep that in mind.
In summary, these things will get you most of the way there:
1) Removing many (not all) of the thickest roots (which will automatically remove a good share of med/fine roots)
2) Trimming back the longest ones so they don't circle around,
3) Removing any "girdling", circling, or J-roots and
4) Removing dead/dying ones that are brown + mushy
Of course, keep balance in mind. If I find an extreme case where removing all of the above would mean removing more than half the root ball, I wouldn't do it all at once.
The idea of top pruning citrus to match with bottom pruning is still debatable. The more recent books I've read on the subject say only top prune in extreme cases of root loss. Otherwise you're removing many nutrients the tree needs, since citrus are different than other fruit trees.
Sorry the post isn't very organized but I hope it helps.
Repotting and root pruning should always be done on well hydrated specimens. I have been told by a nurseryman to use fish emulsion fert several hours prior to potting to coat the roothairs since they start dieing in minutes after air exposure. Seemed to work but I dont always do it.
Rather I usually use a large garbage can and soak the whole container before depotting and untangling the roots. Then I dunk it again every few minutes in a long procedure,or sometimes just leave it in water until the roots become pliable.
Cebury is correct in wanting to root prune in stages if the desired outcome is a large reduction of roots. Maybe 1/4 to 1/3 is OK. I disagree that it is debatable that top prunung is is necessary where a large loss
of roots has occurred. I have potted too many field dug trees to know that is not the case for citrus. It may be OK for dormant deciduous trees to go without top prunning.
I have never seen balled and burlap citrus that were not top prunned. Too much dehydration by transpiration occurs when leaves overbalance the roothairs ability to absorb water. Result is dieback or worse.
It only makes sense to do this in late afternoon and keep the tree in shade for several days until it perks up. I'm
talking about a warm climate environment.
Thanks for the help. That sounds like the way to go. Do you need to worry about root rot after pruning the roots? Should I buy a powder to dip the cut root into to prevent the rot or a fungus/bacterial problem? I want to only remove about 1/4(If I remove the pot and see that it is necessary.) of the roots. I just want to untangle the roots that are girdling and get rid of dead or rotten roots. I am going to buy a larger container with the intention of having that be the final home for the roots. I figure every time I replace the soil, I will check the roots and if they need my attention, then I will take care of it.
I also agree with what you said about removing some of the top growth. I know that the leaves produce the food for the tree but with removing some of the root system, the roots wont be able to absorb as much nutrition as before. It does make sense. Thank you.