I had my yard landscaped last year and one area included two mugo pines. One of the pines died after about two months while the other thrived beautifully. The dead one was replaced this spring with a healthy new one but now, two months later, it is doing the same as the original. All the needles are browning, dried and falling off. It started from the bottom of the plant. It definitely is not from lack of water so I am confused why one is doing so well, only six feet away, and the one in this area dies off. The area is patchy shade throughout the day. I live in Winnipeg,Manitoba in Canada which is a zone 3. The pictures show the dying plant and then a further away shot showing the dying plant on the left between two rocks and the healthy one that was planted last year and is doing well. Any suggestions?
Mugo pine grows best in full sun in well-drained soil. Often when one plant dies of disease, it is best not to put a new plant from the same family in that spot as disease often lingers in the soil. If your soil doesn't drain well, rot may be a problem. Here is an article on mugo pine needle rusts. If you still can't tell which disease is affecting your pine, take a branch to your local county extension office for their help. Moving the pines to a sunnier location may help prevent disease because the plant will be more vigorous.