http://fruitandnuteducation.ucdavis.edu/education/fruitnutproduction/P eachNectarine/Peach_Nectarine_Pests/Peach_Nectarine_Deficiencies/

At this time of year, early October in Zone 7a, would you just ignore it until the spring? First frost date here is generally early to mid-November, so I'm obviously hesitant about giving it any fertilizer, much less a dose of Nitrogen.

On the other hand I have a tendency to over-water, so could I be drowning the poor guy? I've been watering heavily about every four days because we have a drought going on and relatively high temps for this time of year. I'd say our ground in that area is moderate draining, our ground is more sand than pebbles and clay, but a little bit of all.

The spots only showed up recently.

I won't ignore the potential over watering issue. You only need to rewet the rootball that was planted. You aren't trying to recharge the water table. So ease off on the water. When watering a newly planted, potted tree, frequent small waterings to rewet the rootball is the right approach. One gallon will do that.

Now, on your question, I agree with FN that there is no point in fertilizing now and also that it wouldn't hurt, might even help a tiny bit by getting some into the buds for a slightly quicker spring flush although I don't notice this affect on fall fertilizing of peaches. Probably just as well to wait until first growth in spring and then supply another application in early summer.

With trees in potting soil it is easy for them to dry out when first transplanted and that could cause a quick change in leaf color- so it could just as well be too little water as too much. If finer soil around the coarse texture of potting soil is dry it will suck out any water from the potting soil by capillary pull drying it very quickly. At the same time, the coarser mix can't pull water from finer soil. This is a complication with planting potted trees. With peaches I find bare root trees tend to establish faster.

I've seen the result of drought here where rain comes in mid-Aug and causes a sudden burst of growth on many trees in my nursery of many species of fruit followed by a harsh winter with temps in the -15 to -18 degree F. range. The only damage has been to those growing tips. How is this different than a nitrogen application? When it rains after drought there is a burst of available N along with the water in any soil with an appreciable amount of organic matter.

Carl Whitcomb disputes this theory in his book "The Establishment and Maintenance of Landscape Plants" where he states that N. is incapable of taking plants out of their normal cycle of dormancy after late summer. He is an advocate of fall fertilization of trees. Google his name to learn more.

I regularly fertilize fruit trees with a shot of N in Sept and Oct and it never leads to a burst of new growth. Hundreds of trees-many sites. Just did over 100 container trees with urea yesterday.

Winter hardiness is not a completely understood phenomena (and I'm not just talking about myself).

Scott