Managing Sandy Soil

reasons to mulch your trees

Falkenpost / Pixabay

A few years ago, we had a client that moved to an area that is close to a river and the soil is predominantly sand. This can be advantageous in some respects, but when it comes to planting trees, shrubs, or a garden…not so much.

Some benefits of sandy soil are that it is easy to dig in, especially early in the growing season. It also provides excellent drainage.

By amending the soil with some organic matter, it can grow many varieties of flowers and vegetables.  With that said, trees are a little tougher to grow in sandy soil.

Installing Drip Irrigation

One strategy that helps trees to grow in this soil is mentioned in the post below:

The best way to get his trees to survive is the install a direct to root watering system like the aeration tubes, Rootwell Pro318 by Rootwell Inc. After planting the trees, you install aeration tubes around the base of the tree.

A direct to-root-watering system means that you provide your trees with water deep down into the soil, instead of on top. You see, while my neighbor had been watering his trees enough, he was watering them on top of the soil.

See more here…

These customers literally had healthy-appearing trees fall over because of wind and water erosion. Not only is the area sandy, but like other locations along the Front Range of Colorado, there can strong winds.

Maintaining Moisture

Because of this issue, we advised them (among other things) that they needed mulch to help retain moisture and soil. It also keeps the nutrients from leaching out and keeps the soil below ground cooler while preventing evaporation.

In the next video, the narrators discuss the fact that mulch is very advantageous but layering it on too deep can also be harmful to a tree. Watch more on how to mulch your trees:

You want to only have a couple inches depth, but apply the mulch in a wider diameter out to the drip line of the tree. In sandy soil, this wider radius is even more critical for moisture retention.

Purchasing specific plants that don’t mind this finely granular soil is also something to consider. Even though a desert is predominantly sand, there are still quite a few species that thrive in that environment.

Some general options for trees that like sandy soil are mentioned in this article:

Silk Tree

Also known as mimosa, this fast-growing deciduous tree is one of the best for sandy soils. It typically grows to about 30 feet, not quite what is normally considered a shade tree, but it does provide some shade and it doesn’t take decades to do it – five to seven years to maturity is typical.

Black LocustBlack locust seedling

This is a tall, upright hardwood tree that also grows at an unusually fast rate, even in sandy soil. Fragrant white flower clusters emerge from the bare branches in early spring, followed by finely cut foliage and then decorative seed pods in fall. Purple Robe is a popular variety that sports magenta blossoms, instead of the typical white.

Eucalyptus

All species of eucalyptus hail from Australia, a continent with a disproportionate amount of sandy soil. There are numerous varieties, but most are enormous, fast-growing shade trees, some reaching up to 150 feet in height. They are evergreen and emit a pleasing wintergreen-like fragrance from the leaves.

To see more plants that grow well in sand here:  https://garden.lovetoknow.com/landscaping/plants-that-thrive-sandy-soil

Of these three options, the only one that can grow in Colorado’s hardiness zone is the Black Locust. If you have questions about any Denver area landscaping needs, give us a call at (720) 548-2500.