By Mason Opp

Each intern in the Nature Academy internship program at Matthaei Botanical Gardens & Nichols Arboretum chooses a summer project to research and report on. The project culminates in a poster displayed in Matthaei’s public indoor spaces. Interns also write a blog post about their project concept or the research they’ve conducted.

Brick wall in temperate house

Terraces built in the temperate house of the conservatory at Matthaei Botanical Gardens this summer prevent erosion and improve water retention.

Red wiggler worms in furrow

Red wiggler worms being incorporated into the soil to help reduce compaction and turn organic matter into nutrients that plants can use!

If you frequent the conservatory at Matthaei Botanical Gardens you may have noticed that things are looking a bit different this summer. The plants may look a tad greener and the place seems to omit an energy of life spilling over the brim.

Things in the conservatory have been busy and so has a dedicated team of staff, interns, and volunteers. We’ve been working tirelessly, not only to maintain the conservatory and the plants housed within, but to elevate its overall health as part of an ongoing effort aimed at improving soil quality. While my intern project this summer focuses on creating terraces in the conservatory to improve plant health and soil quality, I also wanted to shine a light on the many benefits of worms and compost on soil health.

The soil improvement project has manifested in many ways, but the big three are walls, worms, and lots and lots of compost. Retaining walls in the temperate house were constructed in the late spring in order to reduce soil erosion and increase moisture retention, the effect of which can already be seen through a flourishing ground cover of purple shamrock (Oxalis) under the cork oak (Quercus suber).

Then came the worms. Many, many worms. An army 10,000 strong set forth in the conservatory to vanquish an enemy of plants across the land—soil compaction! When the soil has been watered, stepped or driven on many times it can become heavily compacted as particles settle into each other, reducing space for air and water. The earthworm soldiers help break up compacted soils by diving into the soil in search of food. In doing so they move soil particles out of the way, increasing space for air and water— crucial elements of plant health—to enter the soil. Additionally, they break down organic matter and return the vital nutrients locked within back to the soil in the form of castings (worm poop).

Red wriggler worms

A handful of red wriggler worms.

Terraces in tropical house

A bird’s-eye view shows the three steps of the terraced bed and a trench where hundreds of worms were just released into the bed.

Prepping beds and oxalis

Images during (left) and after construction (right) of the terraces highlight the improvement in the health of purple shamrock (Oxalis triangularis).

After construction in the conservatory

But the worms aren’t just breaking up the old compacted soil, they help to incorporate the tons of compost added to top off the beds. This added compost has brought with it the many nutrients that plants need to thrive, and can already be seen helping the conservatory collection to grow vigorously this summer. In fact we’ve had to get two new compost bins in order to carry out all of the foliage being pruned out of the conservatory!

Mason Opp, from Pinckney, Michigan, is a recent graduate of the University of Michigan Program in the Environment, where he studied environmental policy, law, and sustainability. This summer he joins Matthaei-Nichols as the conservatory intern. He’s excited to make use of the Matthaei Botanical Gardens bike path, ride his mountain bike, and relax at his lake house. Mason’s internship was made possible by Matthaei-Nichols members and individual donors.

Mason Opp