Good news – lichens aren’t the reason your lilac isn’t flowering. But, they might be a sign that your tree’s roots aren’t very happy and the soil is compacted. If it is, take a pitchfork and open up the dirt around the base of the tree. Add some compost. And, some earthworms. They will help work the compost down around the tree’s roots. Now, for the flowers. Or, lack of flowers. There are several reasons for a lack of flowers – too much nitrogen, too much shade, pruning at the wrong time and cutting off the buds, and soil is too wet. With just a few changes in care, you tree should flower every year.
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