I planted two mutigrafted trees in my garden with very similar conditions. The stonefruit tree is growing really well, but the citrus (with lemon and orange) doesnt seem to be growing at all. I was sure it started to grow new shoots this spring, but these seem to have dissappeared. The tree otherwise appears healthy and isnt showing any signs of dying. My only problem is that it has been in the ground for over a year and is still only a foot tall! How do I get this tree to grow?