I live in central Illinois and have a few trees growing very well. I seem to fertilize to far in to the fall and the new growth doesn’t harden off and dies over winter. So at what point do I stop nitrogen and just feed P-K to help store energy and nutrients. What is the best thing to feed at that time. Thanks.
In my experience the fertilizer doesn’t necessarily push new growth as much as pruning does? But from a fertilizer stand point as soon as I see leaf change start on deciduous species I will back off any fertilizer and remove tea bags from trees. Pines and evergreen I will leave fertilizer in place as I feel they will continue to use if needed as they stay somewhat active later into the fall.
I definitely will not do any pruning after August, (approx 60 days from first frost). Allowing everything to harden off.