Construction Soil

When your house was built, the soil was significantly altered. Construction soil can be severely compacted and rocky. This problem persists for many years, long after the bulldozers have moved on.

What can you do to transform construction soil into friable garden soil?

Construction compactor (Public Domain)

What is construction soil?

When a house is built, no one wants it to fall down. Around 500 B.C., a man named Pythagoras figured out the correct angle for walls to be built to reduce the likelihood of collapse. Well, the soil under those walls is equally important for building stability.


Building sites are scraped flat, removing much of the nutrient-rich topsoil, and then mechanically compacted. This is great for your house and terrible for the soil. And if the local soil isn’t stable enough for building, nutrient-poor fill dirt is brought in, mixed in and compacted, until builders have the surface they need. [You can learn more about different types of construction soil at Barclay Earth Depot.] After construction is complete, sod is installed, a few trees and shrubs popped into place, and a cosmetic planting of annual flowers makes everything look lovely. But that appearance can be misleading.

New construction (Steffen Coonan) Pexels

Landscaped new home (Pixabay)

The soil under new construction is reeling in shock. Heavy equipment, trucks, materials, and foot traffic have been crushing the soil, plant roots, microorganisms, insects, and worms for weeks or months of building. Simply adding an attractive top dressing of plants does not correct the problems.

What can you do about construction soil?

Of course, over time, most plants and lawns manage to push roots into the soil and grow. But they could be far healthier and easier to care for if the construction soil they are trying to grow in was transformed into something loose, nutrient-rich, and populated with helpful microorganisms.

Decomposed wood chips and succulents (Kate Russell)

You can make that happen with these tips:

1. Top dress the soil with aged compost. This feeds the microorganisms, worms, and other critters that will help aerate the soil, feed your plants, and improve soil health overall. It also reduces the amount of compostable material that ends up in landfills.
2. Mulch as much of the area as possible with wood chips. You can use mulch to cover the compost, if you want a more attractive appearance, or mulch alone. Wood chips can be acquired for free from local tree trimmers or purchased from garden centers. Wood chips reduce erosion and weeds, stabilize soil temperature and moisture levels, and protect the flora and fauna that help make soil healthy. As the chips break down over the next 3-5 years, they add nutrients to the soil.
3. Plant deep-rooted cover crops and green manures. Cover crops are generally left to grow while green manures are grown to be cut down before going to seed and left in place to decompose. Deep-rooted cereals, such as buckwheat, oats, and rye can help break up compacted soil, while legumes, such as alfalfa and fava beans can improve soil structure and add nitrogen.
4. Instead of bagging grass clippings, leave them where they fall. If you still have a lawn, this grass-cycling is an easy way to feed the soil and life forms that care for the soil and your plants. It’s easier on your back, too.

Compost pile (Kate Russell)

If you do not currently compost kitchen and yard waste, you can easily start a compost pile wherever your least healthy soil is. Simply drop equal parts brown and green materials into a pile, water it and flip it every few days, and within a few weeks (depending on the season) you will have a nice batch of aged compost and that spot will be super-charged with nutrients, microorganisms, worms, and other soil beneficials. If you have a few chickens, adding their bedding and manure to the pile makes it even better!

Finally, get your soil tested by a local lab. Over-the-counter kits are not accurate enough to be useful. Inexpensive lab-based soil tests tell you which nutrients are needed, which are present in excess, and if you have lead-contaminated soil.

Even if you have lived in your home for decades, the effects of construction soil may still be present. Creating healthy soil means that your plants will be better able to defend themselves against pests and disease, along with frost and drought damage. In other words, healthy soil gives you more time to relax!