A: Perhaps you’ve heard of the great gardening myth that dropped pine needles make the soil too acidic and this is why plants do not grow beneath pines. This is mostly a myth! We consulted a few County Extension offices for their take on this common gardening question. (See articles Do Pine Trees Make Soil More Acidic and Myth vs. Reality: What’s the Truth Behind Some Common Gardening Practices.) While pine needles are generally acidic themselves their effect on the soil once broken down is very minimal and not enough to prevent the growth of plants. The bigger problem with planting beneath pines is they often have shallow root systems that make competition high with other plants and the amount of shade they provide can create cool, wet soils and very little sun exposure.
We have not yet created a Garden In A Box specifically for beneath pine trees so we feel hesitant to recommend one and guarantee success. If you’d like to try it out, I would steer you towards one of our more shade-tolerant gardens ( requiring about 4 hours or direct or indirect sun) like Seasons of Shade, Mountain Shadows, or Xeric Greatest Hits- Part Shade. The Lady Bird Johnson Wildflower Organization suggests the following herbaceous perennials for such a location:
Actaea rubra (Red baneberry) – 1-3 ft. tall, rich, moist soils, coniferous woods and thickets, blooms white April to June, sun, part shade or shade.
Aquilegia caerulea (Colorado blue columbine) – 1-2 ft. tall, blooms blue, June to August, medium water use, shade
Melampodium leucanthum (Blackfoot daisy) – blooms white, yellow March to November, 1-3 ft. tall, sun, part sun or shade
Penstemon barbatus (Beard-lip beardtongue) – 3-6 ft., low water use, blooms red June to October, part shade