[jamesn162]

curious. i'm in zone 4 in upstate new york. when can you stop planting trees in my area. the reason i ask is because there are alot of different opinions around here between landscapers.

[Green Man Envy]

You can plant until the ground is frozen too hard to dig.

Last year I did some "fall planting" in my own yard during an early snowstorm. Bit nuts, and I would do my best not to repeat it, but it a shipment of bareroot trees arrived, and I could heel them in or put the extra effort into getting them into their final locations.

I find I have better results with Spring plantings.

[scaper27]

We have planted trees until frost down here on the Island. As lons as they are available. Most nurseries dump alot out to get ready for Spring arrivals

[johnkeegan]

Remember to mulch generously to retard the ground freezing and maybe add something for root growth. Perhaps anti-dessicants if evergreens and in a windy spot and the label says that plant is OK to spray.
A few years back I planted 25 trees (decid. and evergreens) in late Nov./early Dec. in a very exposed spot. They all survived. I treated them all with "Superthrive." Did that make a difference? I can't say for sure but since then I've always used it when planting trees in a "stressful" situation.

[LandArts]

Regarding Superthrive, I noticed if you enter it's ingredients in Google a veterinary B vitamin supplement pops up that's much cheaper...I think something like $60/gallon.