What to Grow Under a Walnut Tree?

Standard
20180526A MONGO, Wikimedia Commons.JPG

Noyer noir (Juglans nigra). Source: MONGO, Wikimedia Commons

Black walnuts (Juglans nigra) and butternuts (J. cinerea), and, although to a lesser  degree, other species of walnut and related hickories (Carya spp.), produce a toxic substance called juglone from both their roots and leaves. Juglone is said to be allelopathic, that is to say, toxic to other plants.

Black walnuts and butternuts use juglone as a defense mechanism: by eliminating competing plants, they can more easily dominate the sector and benefit from all the resources: minerals, water, etc. Even their own nuts have trouble germinating in their root zone, ensuring the mother tree can grow without competition.

If you’re growing a walnut or butternut tree, or intend to grow one, don’t give up all hope of having a beautiful and productive garden at its base. There are still many plants that are juglone-resistant.

The following list keeps growing as more and more plants are tested. Expect to see it updated regularly.

Plants That Will Grow Under Walnut Trees

Vegetables, Fruits and Herbs

  1. Bean (Phaseolus vulgaris)
  2. Beet (Beta vulgaris)
  3. Black raspberry (Rubus occidentalis) zone 4
  4. Carrot (Daucus carota)
  5. Cherry (Prunus spp.) zones 3 to 7, according to species
  6. Corn (Zea mays)
  7. Jerusalem Artichoke (Helianthus tuberosus) zone 4
  8. Maize (Zea mays)
  9. Melon (Cucumis melo)
  10. Nectarine (Prunus persica nucipersica) zone 6
  11. Onion (Allium cepa)
  12. Parsnip (Pastinaca sativa)
  13. Peach (Prunus persica) zone 6
  14. Peppermint (Mentha piperita) zone 4
  15. Plum (Prunus spp.) zones 3 to 7, according to species
  16. Squash (Cucurbita spp.) annual

Climbing Plants

  1. Bittersweet (Celastrus spp.) zone 3
  2. Boston ivy (Parthenocissus tricuspidata) zone 4b
  3. Clematis (Clematis spp.) zones 3 to 8, according to species
  4. Climbing honeysuckle (Lonicera spp.) zones 3 to 7
  5. Currant (Ribes spp.) zone 4
  6. Dutchman’s pipe (Aristolochia macrophylla) zone 4
  7. Lobelia (Lobelia spp.)
  8. Morning glory (Ipomoea nil) annual
  9. Virginia creeper (Parthenocissus quinquefolia) zone 3
  10. Wisteria (Wisteria spp.) zones 4 to 8, according to species

Annuals and Biennials

  1. Begonia (Begonia spp.)
  2. Black-eyed Susan (Rudbeckia hirta)
  3. China pink (Dianthus chinensis)
  4. Cleome (Cleome hasslerana)
  5. Coleus (Plectranthus scutellarioides)
  6. Four o’clock (Mirabilis jalapa)
  7. Impatiens (Impatiens walleriana)
  8. Pansy (Violax wittrockiana)
  9. Four o’clock (Mirabilis jalapa)
  10. Pot marigold (Calendula officinalis)
  11. Sunflower (Helianthus annuum)
  12. Zinnia (Zinnia spp.)

Perennials

  1. Anemone (Anemone spp.) zones 3 à 6, according to species
  2. Aster (Aster spp.) zones 2 to 8, according to species
  3. Astilbe (Astilbe spp.) zone 4
  4. Bellflower (Campanula spp.) zones 3-7
  5. Bellwort (Uvularia spp.) zone 4
  6. Bergenia (Bergenia spp.) zone 3
  7. Black-eyed Susan (Rudbeckia spp.) zones 3 to 7, according to species
  8. Bleeding heart (Dicentra spp.) zone 3
  9. Bloodroot (Sanguinaria canadensis) zone 3
  10. Brunnera (Brunnera macrophylla) zone 3
  11. Bugleweed (Ajuga reptans) zone 3
  12. Buttercup (Ranunculus spp.) zones 2 to 8, according to species
  13. China pink (Dianthus chinensis) zone 4
  14. Christmas rose (Helleborus spp.) zones 4 to 7, according to species
  15. Chrysanthemum (Chrysanthemum x morifolium) zones 4-7
  16. Columbine (Aquilegia spp.) zone 3
  17. Coral Bells (Heuchera spp.) zone 3
  18. Daisy (Leucanthemum spp.) zones 2 to 5, according to species
  19. Daylily (Hemerocallis spp.) zone 3
  20. Dropwort (Filipendula spp.) zone 3
  21. Dutchman’s Breeches (Dicentra cucullaria) zone 3
  22. Echinacea (hybrid) (Echinacea hybrida) zones 3 to 5, according to cultivar
  23. Epimedium (Epimedium spp.) zones 3 to 7, according to species
  24. Evening primrose (Oenothera spp.) zone 4
  25. Foamflower (Tiarella spp.) zone 3
  26. Garden phlox (Phlox paniculata) zone 3b
  27. Gentian (Gentian spp.) zones 2 to 7, according to species
  28. Globeflower (Trollius spp.) zone 3
  29. Goat’s beard (Aruncus dioicus) zone 3
  30. Goldenrod (Solidago spp.) zones 2 to 8, according to species
  31. Hardy geranium (Geranium spp.) zone 4
  32. Hellebore (Helleborusspp.) zones 4 to 7, according to species
  33. Hollyhock (Alcea rosea) zone 3
  34. Horned pansy (Viola cornuta) zone 4
  35. Hosta (Hosta spp.) zone 3
  36. Hyacinth (Hyacinthus orientalis) zone 4
  37. Iris (Iris spp.) zones 3 à 7, according to species
  38. Jack-in-the-pulpit (Arisaema triphyllum) zone 3
  39. Jacob’s Ladder (Polemonium spp.) zones 2 to 6, according to species
  40. Japanese knotweed (Fallopia spp.) zone 3
  41. Joe-Pyeweed (Eupatorium spp.) zones 4 to 6, according to species
  42. Lady’s mantle (Alchemilla mollis) zone 3
  43. Lamb’s ear (Stachys byzantina) zone 3
  44. Leopard’s bane (Doronicum spp.) zone 4
  45. Ligularia (Ligularia spp.) zones 3-4
  46. Lilyturf or liriope (Liriope spp.) zone 6
  47. Lobelia (Lobelia spp.) zones 3 to 9
  48. Lungwort (Pulmonaria spp.) zone 3
  49. Mayapple (Podophyllum peltatum) zone 3
  50. Meadowrue (Thalictrum spp.) zones 3 to 6, according to species
  51. Meadowsweet (Filipendula spp.) zone 3
  52. Obedient plant (Physostegia spp.) zone 3
  53. Pachysandra (Pachysandra terminalis) zone 4
  54. Perennial Sunflower (Helianthus spp.) zones 3 to 6, according to species
  55. Primrose (Primula spp.) zones 3 to 7, according to species
  56. Purple Coneflower (Echinacea purpurea) zone 3
  57. Queen-of-the-prairie (Filipendula spp.) zone 3
  58. Rudbeckia (Rudbeckia spp.) zones 3 to 7, according to species
  59. Sedum (Sedum spp.) zones 2 to 10, according to species
  60. Showy stonecrop (Hylotelephium spectabile, syn. Sedum spectabile) zone 3
  61. Solomon’s Seal (Polygonatum spp.) zones 3 to 7, according to species
  62. Solomon’s seal (Polygonatum spp.) zone 3
  63. Speedwell (Veronica spp.) zones 2 to 7, according to species)
  64. Spiderwort (Tradescantia x andersoniana) zone 4
  65. Spring Beauty (Claytonia spp.) zones 4 to 6, according to species
  66. St. John’s Wort (Hypericum spp.) zones 3 to 7, according to species
  67. Stonecrop (Sedum spp.) zones 2 to 10, according to species
  68. Sweet woodruff (Galium odoratum) zone 3
  69. Tiarella (Tiarella spp.) zone 3
  70. Toad lily (Tricyrtis spp.) zones 4-6
  71. Trillium (Trillum spp.) zones 3 to 6, according to species
  72. Veronica (Veronica spp.) zones 2 to 7, according to species)
  73. Violet (Viola spp.) zones 2-8
  74. Virginia Bluebell (Mertensia pulmonariodes) zone 3
  75. Waterleaf (Hydrophyllum spp.) zones 4 to 6, according to species
  76. Wild ginger (Asarum spp.) zones 4 to 7, according to species
  77. Yarrow (Achillea spp.) zones 2 to 6, according to species
  78. Yucca (Yucca spp.) zones 3 to 6, according to species

Bulbs

  1. Anemone (Anemone spp.) zones 3 à 6, according to species
  2. Bluebell (Hyacinthoides spp.) zone 4
  3. Crocus (Crocus spp.) zone 3
  4. Daffodil (Narcissus spp.) zone 3
  5. Dog’s tooth violet (Erythronium spp.) zones 3 to 7, according to species
  6. Glory of the snow (Chionodoxa spp.) zone 3
  7. Grape hyacinth (Muscari spp.) zone 3
  8. Jonquil (Narcissus spp.) zone 3
  9. Narcissus (Narcissus spp.) zone 3
  10. Siberian squill (Scilla siberica) zone 2
  11. Snowdrop (Galanthus spp.) zone 3
  12. Tuberous begonia (Begonia x tuberosa) tender bulb
  13. Tulip (Tulipa spp.) zone 4
  14. Winter aconite (Eranthis hyemalis) zone 4

Ferns

  1. Christmas fern (Polystichum acrostichoides) zone 3
  2. Cinnamon fern (Osmunda cinnamomea) zone 3
  3. Lady fern (Athyrium spp.) zones 3 to 6, according to species
  4. Maidenhair fern (Adiantum spp.) zone 3
  5. Male fern (Dryopteris filix-mas) zone 5
  6. Royal fern (Osmunda spp.) zone 3
  7. Wood fern (Dryopteris spp.) zones 2 to 8, according to species

Shrubs

  1. Azalea (Rhododendron spp.) zones 3 to 8, according to species
  2. Barberry (Berberis spp.) zones 3 to 8, according to species
  3. Beautybush (Kolkwitzia amabilis) zone 4b
  4. Bladderwort (Staphylea spp.) zones 4 to 6, according to species
  5. Burning bush (Euonymus alata) zone 4
  6. Elderberry (Sambucus spp.) zones 3 to 6, according to species
  7. Forsythia (Forsythia spp.) zones 4-6, selon l’espèce
  8. Hazelnut (Corylus americana) zone 3
  9. Mockorange (Philadelphus spp.) zones 3 to 6
  10. Pagoda dogwood (Cornus alternifolia) zone 3
  11. Rose of Sharon (Hibiscus syriacus) zone 6
  12. Sassafras (Sassafras albidum) zone 5
  13. Serviceberry (Amelanchier spp.) zones 3 to 5, according to species
  14. Shadblow (Amelanchier spp.) zones 3 to 5, according to species
  15. Shrub rose (Rosa spp.) zones 3-7
  16. Shrubby St. John’s wort (Hypericum prolificum) zone 3
  17. Snowball hydrangea (Hydrangea arborescens) zone 3
  18. Spicebush (Lindera benzoin) zone 6
  19. Sumac (Rhus spp.) zones 3 to 8, according to species
  20. Viburnum (Viburnum spp.) zones 2-8
  21. Witchhazel (Hamamellis spp.) zones 4 to 6

Trees

  1. American beech (Fagus grandifolia) zone 4
  2. American elm (Ulmus americana) zone 3
  3. American holly (Ilex opaca) zone 6
  4. American hornbeam (Carpinus caroliniana) zone 4
  5. Arborvitae (Thuja spp.) zone 3
  6. Black gum (Nyssa sylvatica) zone 5
  7. Black locust (Robinia pseudoacacia) zone 4
  8. Buckeye (Aesculus glabra and A. octandra) zone 4
  9. Callery pear (Pyrus calleryana) zone 5
  10. Carolina silverbell (Halesia carolina) zone 5b
  11. Catalpa (Catalpa bignonioides) zone 6
  12. Cherry (Prunus spp.) zones 2 to 7, according to species
  13. Cucumber tree (Magnolia acuminata) zone 5
  14. Eastern hemlock (Tsuga canadensis) zone 4
  15. Eastern redbud (Cercis canadensis) zone 6b
  16. Flowering dogwood (Cornus florida) zone 6b
  17. Fringetree (Chionanthus spp.) zone 5b
  18. Goldenrain tree (Koelreuteria paniculata) zone 6b
  19. Hawthorn (Crataegus spp.) zones 2 to 7, according to species
  20. Hickory (Carya spp.) zones 3 to 6, according to species
  21. Honeylocust (Gleditsia triacanthos) zone 5
  22. Maple (Acer spp.) except silver maple (A. saccharinum), zones 3 to 7, according to species
  23. Oak (Quercus spp.) zones 3 to 8, according to species
  24. Pawpaw (Asimina triloba) zone 5
  25. Persimmon (Diosypros virginiana) zone 6
  26. River birch (Betula nigra) zone 3
  27. Serviceberry (Amelanchier spp.) zone 3 à 5, according to species
  28. Shadblow (Amelanchier spp.) zone 3 à 5, according to species
  29. Silky dogwood (Cornus amomum) zone 4b
  30. Staghorn sumac (Rhus typhina) zone 3
  31. Sweet birch (Betula lenta) zone 3
  32. Sweetgum (Liquidambar styraciflua) zone 6
  33. Sycamore (Platanus occidentalis) zone 6
  34. Tulip tree (Liriodendron tulipifera) zone 6
  35. Virginia pine (Pinus virginiana) zone 6
  36. Willow (Salix spp.) zones 1 to 9, according to species
  37. Yellow birch (Betula alleghanensis) zone 3
  38. Yellow poplar (Liriodendron tulipifera) zone 6

What to Grow Under a Walnut Tree?

Standard

20150628Black walnuts (Juglans nigra), and, to a lesser degree, other species of walnut, produce a toxic substance called juglone from both their roots and leaves. Juglone is said to be allelopathic, that is to say, specifically toxic to other plants.

Walnuts use juglone as a defense mechanism: by eliminating competing plants, they can more easily dominate the sector and benefit from all the ressources: minerals, water, etc. Even their own nuts have trouble germinating in their root zone, ensuring the mother tree can grow without competition.

If you’re growing a walnut tree, or intend to grow one, don’t give up all hope of having a beautiful and productive garden at its base. There are still many plants that are juglone-resistant.

Here’s a list to get you started!

  • Astilbe (Astilbe spp.) zone 4
  • Bean (Phaseolus vulgaris) vegetable
  • Beet (Beta vulgaris) vegetable
  • Bellflower (Campanula spp) zones 3-7
  • Bergenia (Bergenia spp.) zone 3
  • Black raspberry (Rubus occidentalis) zone 4
  • Bleeding heart (Dicentra spp.) zone 3
  • Boston Ivy (Parthenocissus tricuspidata) zone 4b
  • Brunnera (Brunnera macrophylla) zone 3
  • Bugleweed (Ajuga reptans) zone 3
  • Burning bush (Euonymus alata) zone 5
  • China pink (Dianthus chinensis) annual or perennial (zone 4)
  • Chrysanthemum (Chrysanthemum x morifolium) zones 4-7
  • Cleome (Cleome hasslerana) annual
  • Climbing honeysuckle (Lonicera spp.) zone 3
  • Coleus (Plectranthus scutellarioides) annual
  • Columbine (Aquilegia spp.) zone 3
  • Coral Bells (Heuchera spp.) zone 3
  • Corn, maize (Zea mays) grain
  • Crocus (Crocus spp.) zone 3
  • Daffodil, jonquil (Narcissus spp.) zone 3
  • Daylily (Hemerocallis spp.) zone 3
  • Eastern hemlock (Tsuga canadensis) zone 4
  • Epimedium (Epimedium spp.) zone 3
  • Evening primrose (Oenothera spp) zone 4
  • February daphne (Daphne mezereum) zone 3
  • Flowering fern, royal fern (Osmunda spp.) zone 3
  • Forsythia (Forsythia spp.) zones 4-7
  • Four o’clock (Mirabilis jalapa) annual
  • Garden impatiens (Impatiens walleriana) annual
  • Garden phlox (Phlox paniculata) zone 3b
  • Goat’s beard (Aruncus dioicus) zone 3
  • Grape hyacinth (Muscari spp.) zone 3
  • Hardy geranium (Geranium spp.) zone 4
  • Hollyhock (Alcea rosea) zone 3
  • Horned pansy (Viola cornuta) zone 4
  • Hosta (Hosta spp.) zone 3
  • Hyacinth (Hyacinthus orientalis) zone 4
  • Iris (Iris spp.) zones 3-8
  • Japanese maple (Acer palmatum) zone 5b
  • Japanese pachysandra (Pachysandra terminalis) zone 4
  • Juniper (Juniperus spp.) zones 1-7
  • Lady’s mantle (Alchemilla mollis) zone 3
  • Lamb’s ear (Stachys byzantina) zone 3
  • Leopard’s bane (Doronicum spp.) zone 4
  • Ligularia (Ligularia spp.) zones 3-4
  • Lima bean (Phaseolus lunatus) vegetable
  • Lungwort (Pulmonaria spp.) zone 3
  • Male fern (Dryopteris filix-mas) zone 5
  • Meadowsweet, dropwort, queen-of-the-prairie (Filipendula spp.) zone 3
  • Monarda, bergamot (Monarda spp.) zone 3
  • Morning glory (Ipomoea nil) annual climber
  • Northern maidenhair fern (Adiantum pedatum) zone 3
  • Onion (Allium cepa) vegetable
  • Pansy (Viola x wittrockiana) annual
  • Parsnip (Pastinaca sativa) vegetable
  • Showy stonecrop (Hylotelephium spectabile, syn. Sedum spectabile) zone 3
  • Shrub rose (Rosa spp.) zones 3-7
  • Siberian squill (Scilla siberica) zone 2
  • Snowdrop (Galanthus spp.) zone 3
  • Solomon’s seal (Polygonatum spp.) zone 3
  • Spiderwort (Tradescantia x andersoniana) zone 4
  • Sweet woodruff (Galium odoratum) zone 3
  • Tiarella, foamflower (Tiarella spp.) zone 3
  • Toad lily (Tricyrtis spp.) zones 4-6
  • Tulip (Tulipa spp.) zone 4
  • Viburnum (Viburnum spp.) zones 2-8
  • Violet (Viola spp.) zones 2-8
  • Virginia creeper (Parthenocissus quinquefolia) zone 3
  • Wax begonia (Begonia x semperflorens-cultorum) annual