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Tuesday - March 26, 2013

From: Cambridge, MD
Region: Mid-Atlantic
Topic: Problem Plants, Shade Tolerant, Ferns, Grasses or Grass-like, Herbs/Forbs
Title: Plants to grow in shady area near a pecan tree in Maryland
Answered by: Nan Hampton


I live on the Eastern Shore of Maryland. I have planted only natives in my front lawn. My backyard, which sports a pecan tree, fir, fig tree, and others I can't identify is dirt, just dirt. I have tried local grass seeds. Nothing takes. Do you have any suggestions?


I think your problem is twofold:  1) shade and, perhaps, 2) the allelopathic effect of the juglone in the pecan tree.  Juglones are chemicals produced by trees in the Family Juglandaceae (Walnut Family) that are capable of inhibiting the growth of some, but not all, other plants. You can see lists of plants susceptible to juglones and those tolerant of juglones from Ohio State University.  (Be aware that not all the plants on their list are native to Maryland or even to North America.)  It appears that the level of  juglone in Carya illinoinensis (pecan) is less than in walnuts.  Grasses, in general, seem to be tolerant of juglones.  In fact, there have been studies showing that bermudagrass and tall fescue are allelopathic to pecan seedlings!

Here are three grasses and a sedge that occur in Maryland and will grow in the shade or part shade.  I have personal experience with inland sea oats growing quite happily under my walnut tree in Texas and suspect the other three species will also be tolerant of your pecan's juglones.

Chasmanthium latifolium (Inland sea oats)

Elymus canadensis (Canada wildrye)

Muhlenbergia schreberi (nimblewill)

Carex blanda (eastern woodland sedge)

Here are a few herbs and a fern from the Ohio State University list that are native to Maryland and will grow in the shade or part shade:

Arisaema triphyllum (Jack in the pulpit)

Dicentra cucullaria (Dutchman's breeches)

Sanguinaria canadensis (Bloodroot)

Trillium species such as Trillium grandiflorum (Large-flower wakerobin)

Tradescantia virginiana (Virginia spiderwort)

Viola canadensis (Canadian white violet) and Viola pedata (Birdfoot violet) and other violets

Osmunda cinnamomea (Cinnamon fern)

For all the species named above, you should check the other characteristics shown under GROWING CONDITIONS on the species page to determine if they match those of your site.


From the Image Gallery

Inland sea oats
Chasmanthium latifolium

Canada wild rye
Elymus canadensis

Muhlenbergia schreberi

Eastern woodland sedge
Carex blanda

Jack in the pulpit
Arisaema triphyllum

Dutchman's breeches
Dicentra cucullaria

Sanguinaria canadensis

White wake-robin
Trillium grandiflorum

Virginia spiderwort
Tradescantia virginiana

Canadian white violet
Viola canadensis

Birdfoot violet
Viola pedata

Cinnamon fern
Osmunda cinnamomea

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