Browning/dying leaves

[dense1014]

I started these trees from seed about a year ago and had kept them inside using a plant light, until recently when the weather became more consistent without the fear of frost. I started bringing them outside during the day and in again at night to keep them from being a snack for the deer. I started noticing brown spots on the leafs and then they would curl and die. I'm not sure what the cause is and am looking for some help in diagnosing and helping them recover if possible. My thoughts are possibly too much sun and they are getting scorched, too much fertilizer which is also causing scorch, or possibly my pots are too small. I am afraid of re-potting at the moment and causing any more shock to already ailing plants. Any help appreciated, thanks.

[applestar]

What kind of apples did the seeds come from? Apples are/must be cross pollinated by another variety so the result is a hybrid, but knowing one parent might still give us a clue to whether these seedlings would be resistant or susceptible to typical apple diseases.

A deadly disease called fireblight causes crispy burned-looking leaves and blackened stems.

As for the roots, in the future, I recommend planting in tall 1 gallon or larger black nursery pots with lots of drainage holes or -- my favorite for growing trees -- use a 1/2 gallon milk/juice carton with the top cut off (actually, I like to cut in such a way that you fold over the top and staple down to create a more rigid top edge as well as avoid having a cut paper edge at the top. Of course make lots of holes -- I cut OFF the bottom 4 corners for starters, then make additional holes and make slits in the sides with a box cutter.

If using decorative plastic pots such as these, you have to make additional drainage holes especially when using for plants needing really good drainage.

[dense1014]

Thanks for the tips, I believe the seeds were from gala apples if I recall correctly. I drilled nice big drainage holes in the bottom of these pots to ensure they drain well and don't hold too much water.