Planting in Acidic Soil


Planting around your coniferous trees can be difficult becuase of the soil acidity caused by years of needle drop. There are some things you can do to dress these areas up a bit- amending the soil, choosing acid-loving plants, or finding alternatives to planting in that spot.

Soil amendments can be made in acidic areas to help neutralize the space and give you more options for planting. Keep in mind however, that if there is still a coniferous tree in the area it will continue dropping needles and acidifying the soil. Also keep in mind that the area will probably only allow for shallow plantings (from compact soil and tree roots in the way), and so plants should be chosen accordingly. To raise the pH of your soil (make it more basic) use crushed limestone or dolomitic lime. You can also add a layer of fresh top soil- but no more than a couple of inches. Adding more than that may suffocate any surface roots. When making amendments to soil it's always a good idea to add a bit of composted manure becasue this will add nutrients that may have been otherwise depleted.

When choosing plants, choose types that are best suited to acidic soil conditions. Options are limited, but there still are varieties that will thrive:

Shrubs: Azaleas, Rhododendrons, Blueberries, and Hydrangeas

Perennials: Anemone, Astilbe, Epimedium (Barrenwort), Bergenia, Goat's Beard, Goutweed (Snow-on-the-Mountain), Lily-of-the-Valley, Ostrich Fern, Lungwort, Solomon's Seal, Galium, and Bugbane (Snakeroot)

Dig a bit around the roots of the tree to find the best planting spots. Closer to the trunk is best suited for ground cover (less room for rooting- ground covers do not need much depth to root). The spots that have the best depth/width should be saved for shrubs or deeper-rooting perennials.

An alternative option to planting in the ground is to use containers. This offers a few benefits: whatever you plant will not have competition with the tree roots, there are more options of what you can plant, and you can place them as you desire. The biggest setback to this option, though, is that you cannot over-winter anything in pots.