Growing Citrus Trees Without Staking.

[Millet]

The keys are timing, spacing, improved root systems, proper nutrition, shifting plants into larger containers at the proper time and leaving the side branches on as long as practical.  These six factors are critical or you get to sake and stake and tie and tie and wonder why your trees have poor stem diameter/caliper and roots.  You must pay attention to timing relative to the tree's growth.  Once trees in containers, any containers, reach the sidewalls and space for further root development becomes limiting, the tree's  growth pattern becomes like squeezing tooth paste out of the tube, the growth is weak and straight up, and there is no way to get it back into the tube.  ALWAYS leave the lower limbs on the young tree trunks as long as practical.  Research has shown that leaves on the lower trunk contribute most to the development of trunk diameter and strength and good root growth. Air Root Pruning containers are the very best containers for developing a strong trunk and a good root system. It is a matter of root tips and their function.  One root tip can absorb "X" amount of water and nutrients in a day, week or month.  If, by container design and simply using air to dehydrate the root tips, thereby stimulating one root tip to branch  and become 5 and 5 to become 25 and so on, the absorptive capacity of the root system increases dramatically and in turn the leaves are supplied more efficiently with water and nutrients and manufacture more sugars to run the system and positive results occur. As soon the seeds have germinated and are in the propagation containers, they are placed outside in full sun and with full wind.   You want the trunks to bend in the wind as the more the trunks flex the larger in diameter they become (assuming you do not have some other limiting factor) this has been confirmed by some excellent research. It is the resistance against the wind that builds strong straight trunks.  Full sunlight, movement of the young trunks by wind, and proper nutrition are essential, then add  an air root pruning container to build a superior root system and you are off to a great start. - Millet

[brian]

I had heard that letting plants sway in the wind builds strong trunks so I always stake just long enough for the roots to establish and then I remove the stakes. 

I didn't know about the lower leaves being important, though.  I generally pinch off any growth low on the trunk for my taller tree-form plants.  This is mostly because I have a mix of tree and bush-form trees and I can cram more of them in a row if the canopies are staggered high/low.  Adjacent root pruning pots sort of lock together when touching so it keeps the wind from blowing individual trees over.   I guess the question is:  if you know a branch will be heavily shaded is it better to pinch it off entirely or let it survive?

[fyliu]

Thanks for the bit about lower branches. I've been telling that to my family ever since learning about it. Those lower branches that grow horizontally won't be out competing the main trunk and will only contribute to feed the lower trunk. There's no harm in keeping them unless they are the kind that grows straight up.
Those branches also block out reflected light from below. I have a small kishu that's dying because my family likes to prune things, and the lower branches are pruned, and new growth in the wrong direction are pruned. The tree is next to concrete where the sun heats the concrete and that gets reflected up at the tree. It's dying from sunburn but they don't like to be told what to do so I painted the trunk white last weekend.

[robbyhernz]

when to switch to bigger air root containers is something i struggle with. I can't seem to understand the toothpaste analogy.

[buddinman]

I like to let the trees branch 24 tp 30 inches from the soil so the fruit is not touching the ground.

[Millet]

Bonnie, I agree with you 100%  for mature fruit bearing citrus trees, 24 to 30 inches is certainly about correct.    What is being recommended here is to leave  the lower branches on  young non bearing seedling trees.  There is plenty time to cut the branches after the tree has grown and developed a strong trunk. Research has shown that leaves on the lower branches of the trunk contribute most to the development of trunk diameter, strength and root growth. The sugars manufactured by the leaves in the upper part of the tree stay in the upper plant, plus develop buds for the next flush of growth, and later on for for flower and fruit development.  Trees properly grown will have a trunk taper like a good deep sea fishing rod. You will not get such trunk development without leaving on the lower limbs, AND allowing them sufficient light and space to function. Tree height is not the criteria to use when evaluating young tree quality. Trunk diameter or taper is far more important.  Plus tall slender trees always have poor root systems, because roots cannot grow without energy, and most of the energy for their growth comes from the lower limbs. (Plant Production in Containers-II) - Millet