Q. What are good ground cover plants to put under pine trees?
It is difficult to grow plants under pine trees but it can be done. There are three main problems - lack of moisture, lack of sunlight and the low pH (acidity) of the soil. So any plants that you grow there need to deal with these conditions. We suggest the following ground covers:
Creeping wintergreen (Gaultheria procumbens). A densely growing evergreen plant.
Bugleweed (Ajuga reptans). Has purple flowers. Try the variety 'Metallica Crispa'
Sweet woodruff (Galium odoratum). Has white flowers in spring.
Some of the classical groudcovers will also grown under pines but perhaps not as well:
Pachysandra (Pachysandra terminalis)
Vinca (Vinca minor)
You can also try the following plants which are not usually considered to be "groundcovers" but can, in fact serve that purpose: Plant them closer together than usual.
Liriope (L. spicata or L. muscari)..
Lily-of-the-Valley (Convallaria majalis). Scented white flowers in spring.
Wintercreeper (Euonymus fortunei). A spreading shrub
Wild ginger (Asarum canadense)
Ferns. Various ferns will grow under these conditions. Try hay-scented fern (Dennstaedtia punctilobula); royal fern (Osmunda regalis); lady fern (Athyrium filix-femina) and oak fern (Gymnocarpium dryopteris).
It may help to "prune up" your pine trees, i.e. remove the lower branches to allow more light in. Also, the secret of growing any plant under pine trees is to keep the bed well-waterered. This is particularly important in the first year while the new plantings are getting established.
Courtesy of NYBG Plant Information