At present it seems rootballs are poplular despite their increased costs in these tighter value times, whilst I understand that certain species suffer less transplant shock, pyrus, conifers and evergreens such as taxus(yew) when rootballed.
Personally I see little if any real advantage to plant rootballed bareroot broadleaves of most species. I reckon the landscape industries and associated treecare sectors would benefit more from education on improving bareroot planting success and offsetting the costs of balling in this way, such as quicker nursery lifting to plant times, site preparation, post planting care balancing of root to top pruning prior to planting, perhaps if the nursery did this would it be worth paying a premium? The tree has been ripped out the ground by machinery and lost a significant portion of its finer feed and water root system Disadvantages I can think of are.
1. Increased costs in tree and haulage & handling.
2. Safety issues due to heavier weight involved.
3. Slower productivity.
4. Greater chance of introducing invasive weeds and other contaminates/diseases to site,
5. More difficult to replace failures.
6. More reinstatement work on site needed due to handling equipment tracks and ruts, soil displacement or disposal.
7. Metal baskets/nets that fail to corrode, restricting root development
8. Some rootballs are actually lifted bareroot trees, bundled into a hessian and basket with soil and are not lifted rootballs, so no real gain.
9 Damaged by being rolled off trucks and the impacted root system can be severely damaged but not seen.
10. Shrinkage or waterlogging of the ball post planting due to soil differences, e.g clay ball in sand.
Whilst I realise this is only a one sided view I would like to hear your pros and cons or either. I also realise some companies do I fantastic job of moving large trees and supplying excellent stock this is not intended to discredit this kind of rootballing. Im thinking of mainly 5 metres maximum or less in height. Pot grown is often of better quality as it has had tlc, root pruning and formative pruning to make a better transplant.
I personally think its been read or taught to those in managerial positions as a generalisation. Because everybody else does it they dare not risk or challenge the convention. I would on a individual merit according to tree type and site.