I see a lot of great answers here and I went back to posts in 2009 but can't find a similar issue. Magnolia tree, planted 3 years ago, 3 inch dia trunk, each year the flowers are less and the leaves are less and smaller. This year, the tree has leaves that range in size from buds to half the size of normal. There are some smaller short branches that appear to be dying with no leaves but these are smaller 6-18 inch long branches. The leaf growth is fairly uniform around the tree on the other branches, just small leaves. Clay soil, but I did mix mushroom compost when planted (dug hole much larger than root ball). Compost every year on top, 6 foot diameter (about at dripline). Month ago I removed mulch, added some 10-10-10 fertilizer and organic/manure then re-spread and added mulch. Last week I added some holly tone around outside in 5 places using shovel and opening soil, pouring some in, recovering. Overall the "dosage" was less than suggested on package. Leaves are not dying, they are not brown, there are no spots, or stickiness, no mushrooms or anything. Leaves are a lighter green and look somewhat healthy aside from small size, stunted growth and small "seedlings". I've had the nursery out here, and two arborists (one private and one from the city I live in). No one has any suggestions, they say bark/tree look fine. It was a $600 tree so my wife and I really want to stop whatever is happening. If anyone has any suggestions we would greatly appreciate your input. Thank you so much! I should add we did have a warm spring (a week in the 90s), then a cold day with a bit of frost. But last year, the tree was producing less leaves already. Other magnolias in the area have full leaves as well. So I don't think it was the hot/cold spell.