Blue oat grass (Helictotrichon sempervirens) is popular in ornamental gardens because this species forms fountain-like clumps with blue-tinted leaf blades that can add lots of color and texture to your garden spaces.
If you are using blue oat grass as an ornamental plant then it is best to compare it with complimentary companion plant species like dwarf blue spruce, juniper, butterfly bush, turtleheads, or sedum flowers.
These flowers, small trees, or shrubs are sure to make your garden look even more attractive and will complement the vivid colors of the ornamental grasses.
In this guide, we are going to take a closer look at these companion plants for Blue Oat Grass and we discuss different ways to use them in your garden spaces.
What to Grow with Blue Oat Grass
Blue oat grass will only grow well if it is planted in full sun in well-drained soil. The plant prefers moist soil and can tolerate a wide range of soil types from sandy to heavy clay.
In warmer regions, these grasses can act like evergreens but in colder areas, they will be semi-evergreens that can discolor and die back for the winter.
Proper drainage is, however, very important or these perennial grasses can die out completely during the colder winter months.
If you want these charming grasses to stay healthy and vibrant throughout the year then it is best to grow them with plant species that have similar growing requirements.
Let’s take a look at other sun-loving plant species that grow well in moist soil that drains well.
Dwarf Blue Spruce
Dwarf blue spruce (Piceas pungens ‘Globosa’), also known as Colorado spruce, silver spruce, or pino real, is an excellent blue oat grass companion if you want to create a blue-toned garden space. These blue-tinged companions are perfect background plants to fill out your garden or to use in a mixed border.
The evergreen perennial grows slowly and will keep your garden nice and full when the ornamental grasses start to die back during winter.
These specimen plants will grow well in well-drained to dry soil types and should be watered regularly. The foliage of this small tree will stay brightly colored if it is grown in full sun and will create a dramatic effect if you grow clumps of blue oat grass in front of it.
Juniper plants (Juniperus) have similar needle-like leaves as blue spruce but the foliage of these conifers is more green-toned. They do, however, grow blueish seed pods that will complement the ornamental grasses very well.
Juniper bushes will flourish if you plant them in a sunny spot with well-drained soil but some varieties can even take well to full shade positions. These small trees will look striking if you grow them among a garden bed filled with wavy ornamental grasses.
Butterfly bush (Buddleja) or summer lilac is an ideal companion plant for blue oat grass if you want to add lots of color and life to your garden. These shrubs produce vivid clusters of flowers on tall spikes and they come in many different colors including some mixed-color varieties.
The deciduous shrubs will grow vigorously if you place them in full sun in free-draining soil and it requires regular watering. For a striking effect, you can mix blue oat grass and butterfly bushes all over your garden to fill out your spaces or to create showy mixed borders.
Turtleheads (Chelone) or shellflower are good plants to consider if you want to create mixed borders, or hedges, or need to fill out your garden spaces. These plants form dense shrubs with white or pink flowers that can make your garden look vibrant and lush.
The perennial flowers are ideal for gardens around water masses or ponds because they flourish in moist, wet, or murky soil. You can grow them close to the pond edge with blue oat grass clumps a little bit further from the water mass. This combination of florals and texture-rich grasses will create a whimsical waterfront.
Sedum Autumn Joy
Sedums (Hylotelephium spectabile) or stonecrop is an ideal blue oat grass companion for some of the dryer parts of your garden. This flowering species is known to attract lots of butterflies and bees to your garden and they will add lots of charm with their vivid flower clusters.
Autumn joy flowers should be planted in full sun and they only need light watering; they should be planted in well-drained soil or they can develop root rot.
What NOT to Grow with Blue Oat Grass
Since blue oat grass prefers plenty of direct sunlight and free-draining soil, it is usually best not to grow them with shade-loving species that grow well in clay soils.
Gardeners usually avoid planting these grasses with species like ferns, hostas, coral bells, and begonias and you should avoid planting them underneath tall trees or thick shrubs.
Landscaping Ideas for Blue Oat Grass and Companions
There are lots of great ways to use blue oat grass and its companions to create showy spaces in your garden.
Let’s take a look at some of the most popular ways that gardeners often combine and use these plant species to achieve different effects.
Around Water Features
Blue oat grass can handle a lot of moisture which makes it an ideal plant for water masses like fish ponds, lakes, fountains, and other water features.
You can mix these plants with other moisture-loving species like turtleheads, butterfly bushes, and conifers to create a showy display of color and charm in your garden.
Blue-Tinted Garden Beds
Because blue oat grass has blue leaves from summer to fall, lots of gardeners love to use it to create garden spaces with a blueish color palette.
You can mix these beautiful grasses with other blue-tinted species like dwarf blue spruce or juniper trees and blue flowering species for a very interesting garden effect.
Blue oat grass creates a fountain effect if it is grown in bunches. Combine this plant with boulders, rocks, and other ornamentals like sedum autumn joy or butterfly bush and you will be able to create whimsical rocky gardens.
There are lots of creative ways to use and combine blue oat grass and companion plants like dwarf blue spruce, juniper, butterfly bush, turtleheads, or sedum flowers in your garden. We hope that our guide made it a little bit easier to select companion species so you can grow and develop a mesmerizing garden space.
*image by Sergiosk/depositphotos