8 USDA Zone 9 Trees With Non-Invasive Root Systems

Last Updated:
Photo of author
Written By Shannon Campbell

Off-Grid Gardener & Food Forager

This article may contain affiliate links. We may earn a small commission if you purchase via these links. Learn more.
Home » USDA Zone 9 » 8 USDA Zone 9 Trees With Non-Invasive Root Systems

There is so much to consider when choosing trees for your property, and researching the root systems of your chosen species is often the last task on the list.

But it’s an important one, especially if you’re planting trees near important infrastructure.

Many trees have extensive and strong root systems that can disrupt sidewalks and underground cables, while others have water-seeking roots that will seek out pools, water tanks, and septic systems.

If you’re planting trees in an area with important utilities or even near the foundation of your home, you want to choose species with non-invasive root systems that are also compatible with your USDA zone 9 hardiness zone.

Here are eight zone 9 trees with non-invasive root systems for you to choose from.

8 Trees With Non Invasive Roots for Zone 9 Properties

1. Crape Myrtle (Lagerstroemia indica)

Crape Myrtle Tree
Image by vhines200 via Flickr

A genus with over 50 different species, the Crape Myrtle is a beautiful tree that originated in Asia and has since been naturalized in the southern US. Its trees and shrubs are a common sight in the warmer parts of the country, particularly in landscape gardening.

Not only are these trees planted for their handsome, upright forms, lush foliage, and often spectacular colorful flowering displays, but also for their unobtrusive nature.

Though the roots of these trees have a spreading nature, they are generally weak, shallow, and highly unlikely to cause any damage to sidewalks, foundations, or any other nearby infrastructure on your property.

Crape Myrtles are typically planted as specimens, accents, street trees, screens, and hedges.

They require regular pruning to maintain shape, remove suckers, aid in flower production, and more. Growth habits, size, and flower color can change markedly depending on the cultivars you choose.

  • Other Common Names: Common Crape Myrtle, Crepe Myrtle, Crape Flower, Indian Crape Myrtle, Lilac of the South
  • Growing Zones: 6-9
  • Average Size at Maturity: 6-30 feet tall, with a similar spread
  • Flowering Season: Summer

Available at: Fast-Growing-Trees & Nature Hills

2. White Oak (Quercus Alba)

White Oak Tree
Image by Wendy Cutler via Flickr

An enormous, imposing tree, the White Oak won’t be an option for everyone as it needs plenty of space to accommodate it.

But if you’re looking for a large focal point or shade tree that grows well in zone 9 and won’t disrupt your property with its root system, the white oak is worth considering.

The root system of the White Oak is deep and wide-spreading, but as long as the tree is managed properly it is unlikely to be invasive or disrupt nearby infrastructure.

However, if you allow too many white oak seedlings to root and spread, they can become an issue.

Overall the White Oak is a majestic addition to any landscape. It has a large canopy with a wide-spreading crown, along with a lifespan of up to 500 years.

Above all, it is known as one of the US’s most valuable wildlife trees, providing a major source of shelter for local food and wildlife.

  • Growing Zones: 3-9
  • Average Size at Maturity: 60-100 feet tall, with a 50-90 foot spread
  • Flowering Season: Late Spring

Available at: Fast-Growing-Trees & Nature Hills

3. Red Tip Photinia (Photinia x fraseri)

Red Tip Photinia
Image by cultivar413 via Flickr

The most commonly planted type of Photinia is the Red-Tip Photinia, a broadleaf evergreen that can be shaped into both a shrub and a small tree.

It is named for its young leaves, which appear on the tree in a flush of bright red before turning a deep green.

They provide an attention-grabbing colorful display in the first weeks of spring. It also produces clusters of tiny white flowers and pink and red berries.

Aside from root rot occurring in constantly wet soil, the root system of the Red-Tip Photinia is not known to have any issues with invasiveness.

This shrub is most often used to create large formal hedges or informal screens. It can also be used as a specimen or accent tree.

In the southern US, the Red Tip has been somewhat overplanted, leading to the spread of fatal fungal leaf spots for these Photinias according to the Clemson Cooperative Extension.

  • Other Common Names: Fraser’s Photinia, Fraser Photinia, Christmas Berry
  • Growing Zones: 7-9
  • Average Size at Maturity: 12-15 feet tall, with an 8-10 foot spread
  • Flowering Season: Spring

Available at: Nature Hills

4. Trident Maple (Acer buergerianum)

Trident Maple
Image via Nature Hills

A small to medium-sized maple tree, the Trident Maple is a compact, versatile species for zone 9 gardeners. Its root system is not known to have any issues with disruption or invasiveness.

The Trident Maple is a low-branching specimen with a neat, rounded habit, striking exfoliating bark, and beautiful foliage that turns blazing shades of red, orange, and yellow in fall. Each tree consists of three lobes, which is where it gets the name ‘trident’.

Though it lacks some of the elegance and ornamental qualities of more classic maple species it is a very reliable grower – somewhat fast-growing, at a rate of 1-2 feet per year, highly adaptable, and very low maintenance.

Plant the Trident Maple in full sun with moist, well-draining soil. Though it can grow in varying soil types, it should not be planted in alkaline soil, so consider testing the soil first to make sure it is neutral or acidic.

  • Other Common Names: Three-Toothed Maple
  • Growing Zones: 5-9
  • Average Size at Maturity: 25-35 feet tall, with a 15-20 foot spread
  • Flowering Season: Spring

Available at: Nature Hills

5. Chinese Pistache (Pistacia chinensis)

Chinese Pistache
Image by Brian Sterling via Flickr

If you’re willing to put up with a few years of awkwardness for a future beauty, the Chinese Pistache tree is worth considering for your zone 9 landscape. This ‘ugly duckling’ starts off as an unattractive tree in its youth.

Once it matures it becomes a beautifully balanced specimen with a broad, umbrella-like canopy, lovely exfoliating bark, and dense dark green foliage that provides dappled shade.

Its two most attractive features are its fall color, which turns a dramatic flush of orange and red, and its brilliant bright red berries that remain on the tree and turn a deep purple in winter. Consider using it as a specimen, shade tree, or street tree.

The Chinese Pistache has a deep-growing root system that doesn’t spread much and is not going to disrupt sidewalks or cement. It will grow well in varying soil types and pH levels but prefers full sun and rich, moist, well-draining soil.

  • Other Common Names: Chinese Pistachio
  • Growing Zones: 6-9
  • Average Size at Maturity: 30-35 feet tall, with a 20-30 foot spread
  • Fruiting Season: Winter

Available at: Nature Hills

6. American Hornbeam (Carpinus caroliniana)

American Hornbeam (Carpinus caroliniana)
Image by Wendy Cutler via Flickr

This northeastern native is most recognizable for its distinctive blue-gray bark that has a bulging, fluted appearance that resembles muscle tissue, hence the colloquial name ‘musclewood’.

Its bark provides year-round visual appeal, particularly in winter, but its rounded crown, upright, spreading habit, and fine foliage are also attractive.

Perhaps its most ornamental feature is its fall foliage, which lights up the landscape in alternating shades of yellow, orange, and red.

As root systems go, the American Hornbeam’s is wide-spreading but somewhat shallow and ultimately non-invasive. It is best used as an understory specimen, or planted in mixed windbreaks and used to establish small groves and shaded areas.

This native tree is low-maintenance and resistant to serious pest and disease issues.

As an understory tree, it can thrive in partial to full shade, though it prefers to receive at least 4 hours of sun per day. Plant it in fertile, moist, well-draining soil, with a slightly acidic to neutral pH.

  • Other Common Names: Hornbeam, Musclewood, Ironwood, Blue Beech, Water Beech
  • Growing Zones: 3-9
  • Average Size at Maturity: 20-30 feet tall, with a 20-35 foot spread
  • Flowering Season: Mid-Spring

Available at: Nature Hills

7. Downy Serviceberry (Amelanchier arborea)

Downy Serviceberry
Image by Nicholas_T via Flickr

A beautiful understory native, the Downy Serviceberry can be grown as a large shrub or small tree, and it offers plenty of visual interest to your landscape from spring through to winter and back again.

In spring it is smothered in clouds of white blossoms, followed by small purple-blue fruits that look very similar to blueberries and can be enjoyed by both birds and people!

In fall its foliage turns a fiery combination of red, orange, and yellow, and in winter its smooth fissured bark is striking in the bare landscape.

The Downy Serviceberry has an extensive spreading root system that can even be used for erosion control, but they are non-invasive and won’t cause you any issues.

You can use this tree or shrub as a low-maintenance specimen plant, part of a shrub border, or in a native garden.

As an understory tree, it only needs partial shade.

  • Other Common Names: Shadbush, Juneberry, Service-Tree, Sarvis-Tree, Amelanchier Tree
  • Growing Zones: 4-9
  • Average Size at Maturity: 15-25 feet tall, with a similar spread
  • Fruiting Season: Early Summer

Available at: Nature Hills

8. Pincushion Hakea (Hakea laurina)

Pincushion Hakea
Image by Jean and Fred Hort via Flickr

Looking for a standout tree that no one else in your neighborhood will have? Consider the Pincushion Hakea, a native Australian species that is a popular choice of street tree and hedge in its home country.

A large shrub or small tree with an upright growing habit, the Pincushion Hakea is best known for its incredibly unique flowers that look like cherry red pincushions, with long styles that look like pins.

Not only that, but the Pincushion Hakea is an evergreen tree that offers year-round color. It is drought tolerant, grows well in coastal areas, and can be grown as a specimen, accent, and hedge.

The root system of the Pincushion Hakea is certainly not invasive – in fact, you may find it has the opposite problem!

Its roots grow very shallow so the overall system can be quite weak, so you may need to stake your trees to stop them from leaning, and plant in a sheltered location to protect from strong winds.

  • Other Common Names: Sea Urchin, Australian Cushion Flower, Pincushion Tree
  • Growing Zones: 9-11
  • Average Size at Maturity: 10-20 feet tall, with a similar spread
  • Flowering Season: Fall to Late Winter

Protect Your Landscape Infrastructure With These Zone 9 Trees

While invasive roots may seem like a small issue at first, the last thing you want is ruptured cement or a damaged septic system in your yard.

Save yourself time, stress, and money by planting one or more of these trees that have reliable root systems that won’t disrupt any other elements on your property.

Related Articles:

Photo of author

Shannon Campbell

Off-Grid Gardener & Food Forager

Shannon has always loved looking after trees and plants since as long as she can remember. She grew up gardening with her family in their off-grid home and looking after her neighbor's plant nursery. As a child she also participated in native tree replanting, and as an adult has volunteered in reforestation programs in northern Vietnam. Today, she puts her horticultural efforts into tending her vegetable and herb gardens, and learning about homesteading and permaculture. When she’s not reading, writing, and gardening, she’ll be out fishing and foraging for edible flora and fungi in the countryside around her home.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.