I prefer organic trees over non organic trees if they are available, mainly for the reasons mentioned above, like not not being sprayed with toxic stuff and supporting growers who don't do that. However, I'm not really willing to pay more for just that.
However there are other things that are more important to me that seem to affect the success of the plant and its survival more. Most of the time only a
permaculture nursery will do these things, but I would guess that even most
permaculture nurseries don't do all of these things.
The things I look for in order of importance, and I'm willing to pay more for are...
1) strong, healthy, well rooted plants (usually the plants get established a lot quicker and are more resistant to pests and diseases the first year, when they are generally more susceptible to these issues while getting established)
2) grown naturally outdoors in nutrient rich soil, preferably with no
irrigation (by being grown outdoors, the plants are already used to growing in the elements, like hot and cold weather, and are generally "tougher" than ones grown in a
greenhouse and babied more with irrigation and "organic" fertilizers)
3) offered as bare
root (usually has a better natural, spreading and developed root system, and is available to buy and plant during the dormant season, which has greatly increased the success rate of plant survival from the ones I've planted)
Another thing to consider is that some
permaculture nurseries may not be certified organic, (I've heard there are a lot of unimportant and extensive hoops to jump through) but may be offering a product that is much more natural and better than the certified organic trees.
Please excuse my abstract artwork, but this is an illustration of the difference of results I've seen after one year between healthy naturally grown plants and weak certified organic plants. I've also purchased some really healthy certified organic plants, but just because they are certified organic doesn't necessarily mean they will be more healthy. In my
experience, the more they are grown in a way that mirrors the list above, they seem to look like the plant on the left after growing for one year, and the less they mirror the list above, the more they tend to end up looking like the plant on the right after one year. A lot of other factors can influence this, such as location and soil health, but in general and if the plants are planted in a similar location, it seems to be the results.