Gardening Under a Pine Tree
Could you please tell me what I can grow under a 40 year old pine? Do I have to do something special to the ground first? I heard that the pine needles put something into the ground that is not good for other plants.
The combination of shade from the tree and fallen needles (acting as a mulch) have kept weeds and grass from growing under your tree. You do not need to do anything special to the soil. In fact, minimize digging under these and other trees since the majority of tree roots are in the top 12 inches of the soil. Extensive cultivation can damage these vital roots.
Try growing shade tolerant groundcovers under the tree. Spotted deadnettle (Lamium), moneywort (Lysmachia), hosta, wild ginger, ferns, yellow corydalis (can be a bit weedy in milder climates), and astilbe are a few plants that will tolerate these conditions.
Leave the pine needles, they make a great mulch. Just brush aside when planting. Dig a hole slightly larger than the groundcover’s roots to minimize tree root damage. Cover with soil and then slide the pine needle mulch back around the newly planted groundcover. Water thoroughly as needed.