sugar maple problems

i bought 2 sugar maples, 2 yr old bare roots, online. when i got them, i put them in a huge pot for 2 reasons...i didnt want my horses to eat them and i wanted the roots to get a good start before i put them out...we are a mostly clay based soil here. i am currently working on putting up a fence that will seperate the horses from the area i will be planting the trees. but i just discovered that some of the leaves are turning brown and crispy. is this due to a lack of enough sunshine? or is it due to the miracle gro fertalizer i gave them? or is it due to them being in the pot even though it is a huge pot? thank you in advance for your guesstimates...i apologize for the lack of a picture, but i seem to have misplaced my camera :0(

Miracle Grow fertilizer on new (especially bare root) plants can damage them. Try flushing your soil by watering until it runs through. If you have saucers under the pots, remove them and let the water really run through good. Then don't water for a while until the soil dries out (not bone dry though). I wouldn't transplant to the yard until they show signs of recovery. When you do plant them out, don't use any regular fertilizer for the first year. I use Miracle Grow root stimulator which is designed to help the plant put out a good strong root system but not encourage any new green growth. A little Super Thrive would go a long way too (available at Wal Mart). It's not a fertilizer but a mix of hormones and vitamins that really gives plants a boost. Also, I have clay soil too. I dig a very large hole and mix in a generous amount of peat moss at the time of planting--it helps the roots get a good start too. Just be sure you water well if you use peat so you get it thoroughly damp, but not soaking wet. Someone else may have other ideas but this is what I'd do first if they were my trees.

I agree the MG could be causing a problem. It also could be too much sun, if you plopped them all of a sudden out in a sunny area when they were used to a little more shade that can cause problems. Since these were bare-root I'd keep them in a shady-ish location for a while until they start to get going a bit. Or it's possible also that it's a watering issue (either too much or too little) so it wouldn't hurt to check that too. Especially if these were little small trees and you planted them in big giant pots that can make it very easy to overwater things, it's generally best to put it in a pot that is the right size for the plant the size it is now, not the size it will be many months/years in the future.

NatureLover, i think you hit the thing square on the head...what you say makes a lot of sense, thank you for your answer, it has helped me to decide on a course of action which i hope will save the trees. ecrane3 i believe you are right about pot size, but it is too late to worry about it now, as i wont transplant them in the middle of the growing season, also, they are sharing this large pot. thank you both again.