Good soil is the foundation of healthy plants. There are several different soil types, including sandy, loam, clay, or silt. Some soils are better for plants than others, with most native soils needing some sort of amending. It’s crucial to know which kind of soil type you have, and if you need to improve it before adding plants to your yard.
Clay is one of the most challenging soils to deal with. It is characterized by a heavy, sticky consistency when wet, becoming hard and dense when dry. This can restrict the flow and uptake of water and nutrients for plants, impede root growth, and cause water to pool, which can cause root rot and other diseases. Amending clay soil with compost or other rich organic matter improves soil consistency and drainage, while providing crucial nutrients to plants. Also remember, that organic matter does break down over time, so plant slightly high to allow for this.
Some plants are more adaptable to clay soil than others, while there are plants that thrive in clay soil. Here are some of the best clay soil plants.
Zones: 2-9, depending on the variety Exposure: Full sun to partial shade Habit: Pyramidal or mounding habit Height/Spread: 2 to 70 feet tall, 2 to 25 feet wide Bloom time: Flowers insignificant.
Arborvitae is a coniferous tree or shrub with blue-green, gold, or green foliage. This hardy evergreen is commonly used as privacy hedging or in shrub borders. Arborvitae prefers well-drained, loamy soils, but is adaptable to different soils including clay.
Zones: 3-8 Exposure: Full sun to partial shade Habit: Upright spreading habit Height/Spread: 1 to 6 feet tall, 1 to 4 feet wide Bloom time: Summer to fall
This fall-blooming perennial produces daisy-like flowers in shades of white, pink, blue, and purple. Use in mixed borders or native gardens. Asters can grow in clay soil if amended with organic matter. Poor drainage can lead to root rot.
Heavy clay soil can be challenging to garden in. When wet, it becomes sticky and dense. When dry, it hardens into a concrete-like consistency. Poor drainage and compaction are common problems. But don’t despair! With some patience and know-how, you can have a thriving garden, even in stubborn clay soil.
In this article, we’ll explore 10 of the best plants for heavy clay soil. We’ll provide tips on how to prepare the soil, highlight plant features, and explain why these varieties can overcome clay’s tricky texture. With the right plant picks, you can transform your clay-filled garden into a flourishing oasis. Let’s dig in!
Evaluating Your Clay Soil
Before choosing plants, it’s helpful to understand the composition of clay soil. Clay particles are very small, which allows them to pack tightly together. Air and water have difficulty penetrating dense clay. To improve texture, focus on:
-
Aeration – Turn over the soil regularly and add compost to open it up Good drainage and air circulation are key,
-
Organic Matter – Mix in compost, manure, leaf mold and other organic materials. This will lighten heavy clay over time.
-
Mulch – Spread 2-4 inches of organic mulch like bark or wood chips over planting beds. Mulch reduces compaction and retains moisture.
Testing your soil composition and pH can reveal helpful details. Addressing drainage issues, compaction and nutrient deficiencies will give plants their best chance of thriving.
The Top 10 Plants for Heavy Clay Soil
Here are 10 varieties that can overcome clay’s challenges:
1. Black-Eyed Susan
With its large golden-yellow daisy blooms, Black-Eyed Susan (Rudbeckia) brightens gardens from midsummer into fall. This native perennial has deep roots to punch through compacted clay and shallow rhizomes to spread slowly Drought tolerant and pest resistant, it’s tough as nails Black-Eyed Susans thrive with full sun exposure and provide nectar for pollinators.
2. Purple Coneflower
Purple Coneflower (Echinacea purpurea) is a classic native prairie plant that’s adapted to clay’s ups and downs Its long taproot draws moisture and nutrients from deep in the soil profile. Dense clumps of flowers bloom from early summer until fall with minimal fuss Coneflowers thrive with full sun and attract butterflies, bees and birds.
3. Switch Grass
For architectural presence, try Switch Grass (Panicum virgatum). This upright native grass has an expansive, fibrous root system perfect for anchoring in clay. Airy pink flower panicles dance above blue-green foliage that turns golden in fall. Growing 5-6 feet tall, Switch Grass makes a dramatic backdrop for borders. Site it in full sun.
4. Goldenrod
Despite its unfair allergy reputation, Goldenrod (Solidago) is a hardworking native plant suited to clay. It spreads via underground rhizomes to form colonies that choke out weeds. Tiny golden yellow flowers bloom in plumes late summer into fall, attracting beneficial pollinators. Goldenrod does well in sun or part shade and fills large spaces quickly.
5. Astilbe
With its fern-like foliage and feathery blooms, Astilbe thrives in shady sites with moist, fertile soil. Clay’s ability to retain water makes it an ideal environment for Astilbe. This perennial comes in a range of flower colors like pink, red, purple and white. For optimal growth, amend clay soil with compost and mulch to create cool, nutrient-rich conditions.
6. Bee Balm
Also known as Monarda, Bee Balm is a clay-loving perennial. Its minty fragrance and tubular flowers in shades of red, pink, and purple are irresistible to pollinators like bees and hummingbirds. Bee Balm spreads via underground rhizomes, thriving in moist, well-drained areas. Give it full sun to part shade and watch it flourish.
7. Coral Bells
For vibrant foliage, try Coral Bells (Heuchera). This perennial comes in a huge range of leaf colors like deep purple, chartreuse, peach and silver. Dainty flowers appear on tall stalks above the leaves. Coral Bells prefers partial shade and moist, fertile soil which clay can provide. Just amend with compost and mulch for best results.
8. Blazing Star
A classic native wildflower, Blazing Star (Liatris spicata) sends up dense spikes of purple flowers late summer into fall. Its corm-like roots store water and nutrients deep underground where clay doesn’t impede them. For optimum flowering, give Blazing Star full sun and average to dry moisture. Butterflies flock to its nectar-rich blooms.
9. Butterfly Bush
Despite its name, Butterfly Bush (Buddleia davidii) is not native, but this shrub has evolved to thrive in challenging soils. Fast-growing and low-maintenance, its fragrant cone-shaped flowers attract clouds of butterflies and other pollinators. Butterfly Bush tolerates drought, heat, wind and poor drainage – ideal for heavy clay. Give it full sun and ample space to spread its wings.
10. Lenten Rose
Lenten Rose (Helleborus) provides cheery late-winter and early-spring blooms. Its leathery evergreen leaves persist through winter, often with hues of purple, pink and green. Hellebores tolerate heavy, dry clay as well as poor drainage. Part shade and rich organic matter help them truly flourish. Plant them as an understory beneath deciduous trees.
Preparing Clay Soil for Success
With some strategic soil preparation, these plants can put down strong roots in clay:
-
Loosen the soil 12-18 inches deep when installing new plants to allow for root growth. Break up large clumps.
-
Mix in at least a 25% ratio of compost or other organic material to improve drainage and nutrients.
-
Test soil pH and add amendments like lime if needed. Most plants prefer slightly acidic to neutral pH of 6.0-7.0.
-
Improve drainage with French drains or by planting on mounded beds.
-
Mulch heavily with 2-4 inches of organic matter like bark, leaves or wood chips.
-
Water deeply and less frequently to encourage deep rooting. Avoid frequent light watering.
With the right growing conditions, plants can thrive in clay. Proper soil preparation, plant selection and ongoing care will transform your heavy clay into an abundant garden!
BEE BALM (Monarda spp.)
Pardon My Cerise Bee Balm — Buy now from Proven Winners
Zones: 3-9 Exposure: Full sun to partial shade Habit: Upright spreading habit Height/Spread: 1 to 4 feet tall, 1 to 3 feet wide Bloom time: Late spring to fall
This hardy herbaceous perennial produces colorful flowers that resemble fireworks, attracting a range of pollinators. Plant in a wildlife garden or cottage-style border. Bee balm is tolerant of heavy clay, but performs best in rich soil with good drainage. Amend clay soil with organic matter.
Find more on growing bee balm.
Mega Millions® Black-eyed Susan. Photo by: Proven Winners.
RUSSIAN SAGE (Perovskia spp.)
Zones: 4-9 Exposure: Full sun Habit: Upright spreading habit Height/Spread: 2 to 4 feet tall and wide Bloom time: Early summer to fall
This woody perennial produces silvery foliage and lavender-blue flower spikes for a show-stopping effect in the summer landscape. Russian sage prefers hot conditions and lean soil, and is tolerant of clay as long as there is adequate drainage. Waterlogged soil can lead to root rot.
Find more on growing Russian sage.
Rock N Low® Boogie Woogie Stonecrop. Photo by: Proven Winners
Rock N Low® Boogie Woogie — Buy Now from Proven Winners
Zones: 3-9 Exposure: Full sun Habit: Upright, mounding or creeping habit Height/Spread: 3 to 36 inches tall, 12 to 24 inches wide Bloom time: Summer to fall
Sedum is a succulent plant with flowers that add late season color to the landscape. Also known as stonecrop, this carefree perennial tolerates lean and poor soils, including clay, as long as there is good drainage. Use in waterwise borders, or plant along a rock wall.
Find more on growing stonecrop.
Double Play Doozie® Spirea. Photo by: Proven Winners
Double Play Doozie® — Buy Now from Proven Winners
Zones: 4-8 Exposure: Full sun to partial shade Habit: Mounding bushy habit Height/Spread: 2 to 8 feet tall, 2 to 6 feet wide Bloom time: Spring to summer
This versatile shrub is a favorite of home gardeners for its colorful foliage and lacy flower clusters that appear in spring to summer. Spirea is useful in mixed borders or foundation plantings, and adapts well to clay soil as long as there is good drainage. Amend clay soil with organic matter to prevent standing water, which can cause root rot.
Find more on growing spirea.
Prairie Winds® Apache Rose Switchgrass. Photo by: Proven Winners
Prairie Winds® Apache Rose — Buy Now from Proven Winners
Zones: 4-9 Exposure: Full sun to partial shade Habit: Upright, arching or vase-shaped habit Height/Spread: 3 to 8 feet tall, 1-1/2 to 5 feet wide Bloom time: Mid to late summer
Native to North American prairies, switchgrass is a warm-season ornamental grass with steely blue foliage and delicate cloud-like flower plumes that add fine texture to mixed borders and native landscapes. One of the few plants that love clay soil, switchgrass prefers lean soil and moist conditions.
Find more on growing switchgrass.
Blue Muffin® Arrowwood Viburnum. Photo by: Proven Winners
Blue Muffin® — Buy Now from Proven Winners
Zones: 2-11, depending on the variety Exposure: Full sun to partial shade Habit: Upright bushy habit Height/Spread: 3 to 20 feet tall, 3 to 12 feet wide Bloom time: Spring to summer
This deciduous or evergreen shrub is grown for its prolific flower clusters, colorful berries, and brilliant fall foliage that lends multi-seasonal appeal. Use in foundation plantings or native borders. Viburnum is adaptable to a range of soils, including clay, as long as there is adequate drainage.
Find more on growing viburnum.
Red Wall® Virginia creeper. Photo by: Proven Winners
Best Plants For Clay Soils (Top 5)
FAQ
What is the best plant for heavy clay soil?
Roses, Alchemilla and Hydrangeas love clay soil. So do potatoes, beans, peas, fruit trees and anything that would grow happily in large pots (as you can dig a hole and dump a bag of compost and sand in as though it’s a pot).
What should I add to heavy clay soil?
… in autumn can be very effective, especially if it is spread on the soil surface with copious amounts of organic matter such as garden compost or bulky manure
What is the best cover crop for heavy clay soil?
Daikon Driller Radish – Soil Aeration: Daikon radishes have deep taproots that can be up to six feet long, making them the best cover crop for heavy clay soil.
Does anything grow well in clay?
Mid and late season sweet corn are a good choice, too, but some of the best vegetables to grow in clay are squash and pumpkins.Feb 13, 2015