17 Plants That Grow Beautifully Under Oak Trees

Thinking about adding some perennials or blooming shrubs beneath the oak trees in your garden? The good news is, you absolutely can. While oaks cast dense shade and have extensive root systems that compete for water and nutrients, there are still plenty of plants that will thrive under them, and many bring color, texture, and year-round interest to your landscape.

The key is choosing plants that tolerate shade and dry conditions, especially in summer when oak roots pull most of the available moisture from the soil. Deep-rooted species that don’t disturb the shallow feeder roots of oaks are ideal, and native plants are always a safe bet, as they’re adapted to the local conditions.

In the guide below, we explore a variety of perennials, groundcovers, and shrubs for planting under oak trees. Each plant includes its common name, scientific name, and USDA hardiness zones so you can make informed choices for your region. Let’s take a closer look at some of the best companion plants for the space beneath your oaks.

Depending on the variety, azaleas can stay compact or reach up to 10 feet tall. Their blooms appear in a wide range of colors, including red, yellow, white, pink, and purple, and they typically flower from March through July, sometimes even beyond.

Bush Poppy

	botanical name Dendromecon rigida
	plant type Shrub
	sun requirements Full sun
	height 10 feet
	hardiness zones 8-10

The evergreen bush poppy has finely toothed, leathery leaves and can reach six feet tall within two years. Blooming from late winter through mid-spring, it produces bright yellow flowers and typically spreads between two and eight feet wide. The plant has a funnel-like shape and is native to Baja California.

Its thin, elongated leaves display a striking blue-green hue. After flowering, the plant produces fruit containing smooth brown or black seeds. Bush poppies thrive on rocky clay slopes and are excellent for supporting butterflies, bees, and other pollinators. Plant it slightly away from the shaded canopy of your oak tree to get the best blooming, as it requires full sun.

California Fescue

	botanical name Festuca californica
	plant type Grass
	sun requirements Full sun to partial shade
	height 1-4 feet
	hardiness zones 7-11

California fescue is a hardy native grass found in various plant communities across California and Oregon. It features narrow, resilient leaves that can grow quite long, and it reproduces from the base via creeping roots, and with seeds that form in summer and fall.

Often used to revegetate previously cleared grasslands, California fescue grows at a moderate to fast pace. It produces yellow flowers that attract both butterflies and moths. Low-maintenance and drought-tolerant, this grass is a great choice for planting under oak trees.

The evergreen or semi-evergreen leaves are rounded and lobed, coming in a wide range of colors including lime green, gold, rose, and purple. Flower colors vary too: orange, pink, red, and white are all common. For best results, plant under oak trees in late fall or early spring. They are long-lived perennials.

Creeping Sage

	botanical name Salvia sonomensis
	plant type Herbaceous perennial
	sun requirements Full sun to partial shade
	height 1-2 feet
	hardiness zones 7-11

Creeping sage grows naturally in California’s Peninsular Range, Coastal Ranges, and Sierra foothills. This herbaceous perennial shrub, part of the Salvia genus, features hairy stems that reach up to about 15 inches tall. The leaves are also hairy, with the lower ones forming a dense, white-colored base.

Its flowers appear in shades of blue, lilac, purple, and white, attracting hummingbirds, bees, butterflies, and other pollinators. Creeping sage is well adapted to dry conditions and thrives in a variety of soil types with minimal water.

Deergrass

	botanical name Muhlenbergia rigens
	plant type Grass
	sun requirements Full sun
	height 4-5 feet
	hardiness zones 6-11

Deergrass is known for its dense foliage and long, pointed leaves that can grow up to three feet in length. The leaf color varies from silver-green to shades of purple. When in bloom, the plant can reach a height of five feet.

Commonly found in oak woodlands, grasslands, mixed conifer areas, and riparian zones, deergrass produces flowers in soft yellow or cream tones. It thrives in sandy or gravelly soils but can adapt to most well-drained soil types. The plant blooms in spring and needs weekly watering during its initial growth period.

Douglas Iris

	botanical name Iris douglasiana
	plant type Herbaceous perennial
	sun requirements Full sun to partial shade
	height 1-2 feet
	hardiness zones 7-9

The Douglas iris is a common wildflower that thrives at low elevations, typically below 330 feet. It’s often found in grasslands near coastal areas and grows best in rich soils with partial shade, ideal for planting under oak trees.

Its blooms come in a wide range of colors, including white, yellow, purple, blue, and pink. Douglas iris prefers cooler temperatures and needs watering every two to four weeks. The flowers attract butterflies and several moth species.

Flannel Bush

	botanical name Fremontodendron californicum
	plant type Shrub
	sun requirements Full sun
	height 6-20 feet
	hardiness zones 8-10

The flannel bush is a fast-growing evergreen shrub known for its striking yellow flowers and fuzzy, olive to gray-green leaves. Native to the mountains of the Transverse and Peninsular Ranges, as well as the hills around San Francisco, this plant thrives in sunny spots with well-draining sandy or chalky soils.

Flannel bush is drought-tolerant and hardy down to about 20°F (-7°C), making it a resilient choice for gardens in southwestern North America at elevations above 1,300 feet. It also attracts a variety of pollinators, including bees, butterflies, and moths. Though it won’t bloom as much directly under oak trees, planting just outside the canopy range promotes a stunning display.

Grape Hyacinth

	botanical name Muscari armeniacum
	plant type Herbaceous perennial
	sun requirements Full sun to partial shade
	height 6-9 inches
	hardiness zones 4-8

Grape hyacinths are low-maintenance, early-blooming plants that add a splash of color to your garden when planted under oak trees. These small, bell-shaped flowers are typically a rich, dark blue and grow on light-green stalks that reach up to 8 or 9 inches tall. After blooming, the plant produces green seed pods that often persist into late summer.

You can plant grape hyacinths in the fall, and they’ll reliably emerge when the weather warms. They prefer full sun but can tolerate partial shade and thrive in well-draining soil. Their compact size and vibrant color make them ideal for borders, under trees, or naturalized in lawns and meadows.

Holly

	botanical name Ilex aquifolium
	plant type Shrub
	sun requirements Full sun to partial shade
	height 30-50 feet
	hardiness zones 7-9

Holly is a classic evergreen shrub known for its spiny green leaves and vibrant red berries, which provide striking winter interest in the garden. It thrives in moist, well-drained soils and naturally grows in forest edges, woodlands, and near swamps. While holly can tolerate full sun, it benefits from partial shade during hot summer months to prevent leaf scorch.

The leaves are thick, leathery, and edged with small spines, often appearing in glossy green with occasional yellow tones. In late spring (typically from May to June) holly produces small greenish-white flowers. These blooms give way to the bright berries that ripen in autumn and persist through the winter, offering both beauty and a valuable food source for birds.

Plant these under mature oak trees to prevent shading out the oak as it grows.

Hostas

	botanical name Hosta spp.
	plant type Herbaceous perennial
	sun requirements Partial shade
	height 6-36 inches
	hardiness zones 3-9

Hostas are beloved shade perennials, and for good reason. With their lush foliage and wide variety of sizes and colors, they bring texture and elegance to any shady garden bed. Blue hosta varieties, in particular, thrive in deep shade, making them ideal for planting under oak trees that cast heavy canopy cover.

If your oak tree is younger and allows more light through, you can choose lighter-colored hostas, such as yellow or green varieties, that tolerate dappled sunlight better. These hardy plants are not only low-maintenance but also adaptable to a range of climates, including colder regions, where they return reliably year after year.

Mahonia

	botanical name Berberis aquifolium
	plant type Shrub
	sun requirements Partial shade
	height 3-6 feet
	hardiness zones 5-9

Mahonia shrubs are an excellent choice for planting beneath oak trees. Their dense structure and bold, architectural foliage create a striking visual contrast to the tree canopy above. Native to North American woodlands, Mahonias are well-suited to shady environments and thrive in the dappled light beneath mature oaks.

In late winter to early spring, Mahonias produce clusters of golden-yellow, bell-shaped flowers that provide early nectar for pollinators like bees and butterflies. These blooms are followed by dark blue to black berries that attract birds, adding further life to your garden.

Monkey Flowers

	botanical name Mimulus aurantiacus
	plant type Shrub
	sun requirements Full sun to partial shade
	height 3-5 feet
	hardiness zones 7-11

Monkey flowers are vibrant, eye-catching perennials native to the southwestern United States, including Southwestern Oregon, California, and Baja, Mexico. Their blooms come in a range of striking colors (red, white, orange, and yellow) that make them stand out in any garden setting. With rich green foliage and a naturally bushy habit, these plants provide a lush, lively presence throughout the growing season.

Monkey flowers are pollinator magnets, regularly visited by bees, hummingbirds, moths, and other beneficial insects. Though the blooms don’t have a noticeable scent, their bright color and tubular shape are irresistible to wildlife.

These shrubs thrive in tough conditions, growing best on rocky or sandy hillsides, canyon slopes, cliffs, and open woodlands. They prefer well-draining soil and can handle dry conditions once established. Their moderate growth rate and evergreen habit make them a low-maintenance but rewarding addition to native and wildlife-friendly gardens.

Oak Leaf Hydrangea

	botanical name Hydrangea quercifolia
	plant type Shrub
	sun requirements Full sun to partial shade
	height 4-8 feet
	hardiness zones 5-9

The oakleaf hydrangea is a deciduous shrub with fuzzy leaves shaped like oak leaves. By late fall, the leaves turn purple and red. White flowers bloom in late spring and summer. This plant grows best in moist soils with enough mulch to retain moisture.

In winter, it should be sheltered from harsh conditions. The bark on mature plants turns reddish-brown, and the shrub typically blooms in May or June. It can also tolerate sandy soil and dry environments.

Purple Needlegrass

	botanical name Nassella pulchra
	plant type Grass
	sun requirements Full sun to partial shade
	height 2-3 feet
	hardiness zones 7-11

Purple needlegrass grows well in oak woodlands and grasslands, making it a smart choice for planting beneath an oak tree. It thrives in clay and serpentine soils. The long stems can reach up to 3 feet tall, while the roots grow as deep as 20 feet into the ground.

This evergreen plant blooms in spring, with flowers in shades of green, purple, red, and cream. Although it has no fragrance, it attracts butterflies, moths, birds, and other insects.

Shooting Star

	botanical name Primula meadia
	plant type Herbaceous perennial
	sun requirements Partial shade
	height 9-20 inches
	hardiness zones 4-8

The shooting star produces one-inch pink, white, and purple perennial blooms and is commonly found on American prairies. It grows in moist soils in woodlands and on rocky slopes, thriving in spring before going dormant in summer.

In cooler climates, it prefers full sun, while in warmer regions it benefits from partial shade. Well-draining sandy loam soils work best. The plant needs about an inch of water per week. It doesn’t require fertilizer and can survive cold winters without intervention.

Wild Lilac

	botanical name Ceanothus spp.
	plant type Shrub
	sun requirements Full sun to partial shade
	height 2-20 feet
	hardiness zones 7-10

Wild lilac brings a vivid splash of blue when in bloom beneath oak trees. With around 50 species (most evergreen and some deciduous) this shrub can be grown as a freestanding specimen or trained along walls, fences, and doorways.

Plant wild lilac in spring, choosing a spot with full sun and well-drained soil. Blossoms appear in shades of pink, white, and blue. While newly planted shrubs need regular, deep watering, mature plants are drought-tolerant and require little to no water. Protect them from heavy winds and winter frost for the best results.