American Elm trees (Ulmus americana) are an iconic species native to eastern and central North America. Known for their fast growth rate and vase-shaped canopy, American Elms were once a dominant street tree in many cities and towns. Unfortunately, Dutch Elm Disease devastated elm populations in the mid-20th century.
However, some American Elm varieties have developed disease resistance, and the species is making a comeback. In this article, we will explore the best companion plants to pair with American Elm trees to maximize their growth, health, and aesthetic appeal.
Key Takeaways
- American Elms prefer full sun but tolerate partial shade
- They have moderate water needs and grow in most soil types
- Companion planting aids soil health, pest/disease control, and pollinator attraction
Understanding American Elm’s Growing Requirements
Lighting requirements
American Elm trees grow best in full sun but can tolerate partial shade. They require at least 6 hours of direct sunlight per day for optimal growth. In shaded conditions, elms are more prone to disease and pest issues.
Watering needs
American Elms have moderate water needs. Their soil should be kept consistently moist but not soggy. Infrequent, deep watering is preferable to frequent light watering. Elms can tolerate short drought periods once established.
Soil preferences
American Elms are adaptable to most well-drained soil types including clay, loam, and sandy soils. However, they grow best in moist, fertile soils rich in organic matter. Ideal soil pH ranges from 6.0 to 7.5.
Temperature tolerance
Elms are extremely cold hardy and can withstand winter temperatures down to -30°F. They are also fairly heat tolerant, though young trees may struggle in temperatures over 95°F. Zones 3-9 are most suitable.
Companion Plants for Shade and Shelter
Providing the right microclimate is important for successful American Elm growth. Shade-loving plants underneath the canopy help conserve moisture while sheltering companions offer protection.
Plants that provide shade
- Serviceberry (Amelanchier spp.) – native shrub bears colorful spring flowers and edible berries
- Coralberry (Symphoricarpos orbiculatus) – dense foliage offers humidity and shelter for birds and pollinators
- Virginia creeper (Parthenocissus quinquefolia) – deciduous vine with fall color and edible berries
Plants that offer shelter
- Bamboo muhly grass (Muhlenbergia capillaris) – ornamental grass with stiff foliage blocks wind
- Lilac (Syringa vulgaris) – fragrant spring blooms on an upright, sturdy structure
- Butterfly bush (Buddleja davidii) – summer-blooming shrub is a magnet for pollinators
Plants for Soil Health
Soil organism diversity is key to building healthy soil. These companion plants nourish the soil web.
Plants that improve soil structure
- Comfrey (Symphytum officinale) – dynamic accumulator drops nutrients deep into subsoil
- Crimson clover (Trifolium incarnatum) – winter cover crop adds nitrogen, improves tilth
- Chicory (Cichorium intybus) – deep taproot draws up minerals, loosens tight soils
Plants that help control pests and diseases
- Garlic (Allium sativum) – deters insect pests and parasitic nematodes in soil
- Oregano (Origanum vulgare) – powerful essential oils deter fungal diseases and some insects
- Yarrow (Achillea millefolium) – drought tolerant herb supports predatory insects
Plants that Complement American Elm’s Growth Habits
Pairing trees with compatible sized companions creates a harmonious landscape design.
Plants with similar growth rates
- Linden (Tilia cordata) – fast growing, pyramidal shade tree provides summer flowers
- Red maple (Acer rubrum) – zone 3 hardy, similarly vase-shaped canopy, excellent fall color
Plants with comparable spreads
- Shagbark hickory (Carya ovata) – native nut tree has an arching habit and yellow fall tint
- River birch (Betula nigra) – exfoliating bark adds winter interest, spreads at similar pace
Flowering Plants that Attract Pollinators
Ensuring a continuous nectar source fuels pollinator health and diversity. their mutualistic relationships also pollinate fruits/nuts on companion plants.
Plants that attract bees
- Basils (Ocimum spp.) – culinary and ornamental herbs flower July-September
- Russian sage (Perovskia atriplicifolia) – drought tolerant, gray foliage, summer blooms
Plants that attract butterflies
- Lantana (Lantana camara) – resilient annual bears orange, pink or yellow blooms
- Ironweed (Vernonia spp.) – native perennials bloom August-October, host caterpillar foodplants
Plants that provide pollen
- Sunflowers (Helianthus spp.) -annuals/short lived perennials burst July-September
- Asclepias tuberosa -Orange butterfly weed, host monarch caterpillars as well as pollen source
Plants that Enhance American Elm’s Medicinal Properties
Elm trees produce mucilage sap containing antioxidants and natural medicines. Pairings improve nutritional profiles.
Herbs with similar medicinal qualities
- Dandelion (Taraxacum officinale) – root and leaf teas support digestion and liver detoxification
- Lady’s mantle (Alchemilla mollis) – tones uterus, eases menstrual cramps and hot flashes
Plants that boost immunity
- Echinacea (Echinacea purpurea) – perennial daisy enhances immune function year-round
- Ginger (Zingiber officinale) – highly anti-inflammatory, aids circulation and digestion
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Plants that Repel Pests and Diseases
Interspersing resistant varieties disrupts pest cycles and barriers deter disease spores.
| Pest/Disease | Repellent Plant | Method |
| Japanese beetles | Rosemary (Rosmarinus officinalis) | Powerful scent deters feeding |
| Aphids | Dill (Anethum graveolens), fennel (Foeniculum vulgare) | Encourage lacewings and ladybugs |
| Powdery mildew | Garlic (Allium sativum) | Potent antifungal compounds |
| Verticillium wilt | French marigolds (Tagetes patula) | Excrete fungitoxins from roots |
Plants that repel pests
- Mint family (Lamiaceae) – strong scents deter many insects from feeding/laying eggs
- Nasturtiums (Tropaeolum majus) – colorful flowers attract predatory insects over pests
Plants that prevent disease
- Pineapple sage (Salvia elegans) – protectively coats foliage with antifungal oils
- Lavender (Lavandula spp.) – calming essential oils deter fungal/bacterial pathogens
Plants for Aesthetic Appeal
Ornamentals provide contrasting textures, colors, and forms to create an appeal gardening landscape design.
Plants with contrasting foliage
- Hostas (Hosta spp.) – lush, low growing leaves offer shades of green, variegation
- Ferns – delicate, airy foliage has a natural, soothing quality
Plants with colorful bark
- Paperbark maple (Acer griseum) – exfoliating cinnamon, cream and apricot bark stands out in winter
- Crepe myrtle (Lagerstroemia indica) – sculptural, smooth trunk adds summer blooms too
Plants with unusual structures
- Smoke bush (Cotinus coggygria) – feathery plumes float on airy stems mid-summer
- Weeping cherry (Prunus subhirtella ‘Pendula’) – branches cascade in a gentle wave
Final Thoughts on American Elm Companion Plants
There are countless pleasing combinations to experiment with when planting American Elms. Choosing companions aligned with the tree’s growing preferences helps it thrive with minimal maintenance.
Interspersing pollinator magnets, soil enrichers, and pest deterrents improves the ecological function of the planting as well. With care, an American Elm can become a multigenerational landscape asset once again gracing communities across eastern North America.
References & Citations
https://www.arborday.org/trees/treeguide/TreeDetail.cfm?ItemID=787 https://www.gardeningknowhow.com/ornamental/trees/elm/growing-american-elm-trees.htm
https://www.thespruce.com/growing-american-elm-trees-2132574
Frequently Asked Questions on American Elm Companion Plants
Q. Can you plant under an elm tree?
A. Yes, some suitable plants for under an elm tree include English ivy, periwinkle, wild ginger, hostas, bleeding heart, sweet woodruff, ferns and coarse grasses. They adapt to shade and will not compete heavily with the elm’s extensive roots.
Q. Where is the best place to plant an elm tree?
A. Elms grow well in most temperate zones but prefer full sun to part shade and moist, well-draining soil. They make nice landscape specimens and are suitable as street trees due to their vase shape and tolerance of pruning and urban conditions.
Q. What are common issues with elm trees?
A. Dutch elm disease is a serious fungal issue. Signs include wilting, yellowing leaves and bark beetle damage. Proper pruning also prevents buildup of deadwood that beetles may lay eggs in. Gypsy moths can defoliate.
Q. Do elm and pine trees grow together?
A. Yes, elms and pines are commonly grown together, especially American elm and eastern white pine. Their native ranges overlap and they prefer similar well-drained soil conditions. Plant them at opposite borders for garden interest.
Q. What can I plant near an elm tree?
A. Perennials, shrubs and groundcovers suitable near elms include hostas, ferns, bleeding hearts, peonies, lavender, monarda, lilacs, potentilla, astilbes, euonymus, and creeping phlox. Most thrive in partial shade and benefit from elm’s moisture retention.
Q. Does American elm have invasive roots?
A. Elm roots are very prolific but not considered highly invasive underground. They spread laterally mores than vertically and can compete with other nearby planted trees or shrubs over time. Proper spacing avoids issues during most trees’ lifetimes.