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Saturday - April 16, 2011

From: Philadelphia, PA
Region: Mid-Atlantic
Topic: Wildflowers
Title: Wildflowers for a slope in PA
Answered by: Anne Bossart


I've got a steep southeast-facing slope near the house that is mostly overrun with day lilies. It gets plenty of morning sun. I've had some luck with goldenrod and New England aster along the steps as long as I weed the day lilies back regularly, but I'd like plants compatible with the goldenrod/NE aster combination to replace the day lilies altogether. The area is about 5 feet high by 3 feet wide. Summer blooming would be a plus, but grasses would also be OK.


You are using the right strategy on that slope, gradually replacing the daylilies with more appropriate wildflowers.  They will keep your slope stable as your new plants take hold.

Ornamental grasses, with their fibrous root systems really are the best plants for a slope but there are many herbaceous plants (perennials and annuals) that will do the job and will complement your late summer/fall blooming asters and goldenrod.

To generate a list of these plants, do a combination Search on our Native Plant Database. Select: Pennsylvania/Herb(aceous plant)/Part shade/Your soil conditions(probably dry or moist depending on how much clay you have and how steep the slope is)/blooms in June,July (you choose).  You can also narrow your search by color choice and size. Each plant name on the list is linked to a more detailed information page.

There are many to choose from, and you will ultimately be limited by the plants you can locate in the nurseries, but this "Green Guru" has lived in the Philadlephia area and knows just how many great nurseries you have to choose from!  Here are a few of my favourite meadow wildflowers that I know will do well for you.

Asclepias tuberosa (Butterflyweed) (you HAVE to plant this one for the monarch butterflies)

Coreopsis lanceolata (Lanceleaf coreopsis)

Echinacea purpurea (Eastern purple coneflower)

Gaillardia pulchella (Firewheel) (this is not dependably perennial but self seeds, so it moves around the garden)

Monarda fistulosa (Wild bergamot) (this really spreads but is easy to pull out and share)

Rudbeckia hirta (Black-eyed susan) (the velvety dark brown "eyes" persist throughout the winter and are great in dried arrangements)

A similar search for grasses will generate a similar list.  Here are a few recommendations:

Panicum virgatum (Switchgrass) (the seed heads light up in the fall sunshine)

Schizachyrium scoparium (Little bluestem) (this doesn't take too much space but the rusty fall color lasts through the winter)

Sorghastrum nutans (Indiangrass) (this one is great but might be a bit too big for your space)

Here are some photos from our image gallery:

Asclepias tuberosa

Coreopsis lanceolata

Echinacea purpurea

Gaillardia pulchella

Monarda fistulosa


Panicum virgatum

Schizachyrium scoparium

Sorghastrum nutans






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