When Is The Appropriate Time To Cutback?

Finding the right time to cut back grasses and perennials can be a difficult task, especially when considering the impact on local wildlife, plant health and maybe even what your neighbors think of your garden. With nearly endless rules and opinions, we wanted to put together a few important considerations when scheduling your spring cutback.

Leaving the remains of our gardens through the winter is not only great for pollinators and insects but it is beautiful! In Colorado, the skeletons of our summer plants form the texture and color of winter gardens. At Tree of Life, our gardens are designed specifically for winter interest. Colorado affords us the right climate to enjoy the varied colors of winter. Leave your gardens up and provide habitat for nesting wildlife and enjoy the beauty.

When it comes time to cut back your space, consider the following points and see what best fits your unique situation.

Pollinators and Stem-Nesting Bees

Many of us know that leaving the skeletal remains of the summer’s perennials and grasses provides important winter habitats for insects, but stem-nesting bees need habitat through the summer as well. These insects will lay their insects in hollow stems in the spring and the larvae will remain there for the whole summer and emerge the following spring. For this reason, The Xerces Society recommends leaving 24 inches of stems that are suitable for stem-nesting bees and cutting them down every other year. This may look different from a traditional cutback, but the spring growth will soon cover the remaining stalks. If you are trying to prioritize habitat for stem-nesting bees, we recommend this type of cutback, especially for these species: 

• Monarda sp. 

• Rudbeckia sp. 

• Echinacea sp. 

• Solidago sp. 

• Aster sp. 

• Symphyotrichum sp. 

• Asclepias sp. 

• Agastache sp.

• Hydrangea arborescens
  

Gravel Gardens 

For gardens with a gravel mulch, you will want to cut back all grasses and perennials and remove the biomass to avoid adding another layer of soil over the rock mulch. We like to remove this plant matter and compost it separately. You can add the compost back into the soil when adding plants to your garden.

Don’t Forget Ephemerals 

For many of us gardeners, spring ephemerals are the first blooms of the garden and we don’t want the old plant material to obstruct our spring crocuses. Myself, a gallanthophile, I never want to damage my snowdrops by cutting back later in the season. 

Mow and Mulch

If you know that the species in your garden can withstand a spring mow, you may be able to simply mow and mulch the entire garden. Cool season grasses like Helictotrichon and some warm season grasses like Sporobolus heterolepis can suffer if their crown is scalped by a low mow, so it is important to know which species may require additional attention.

Grazing 

We often separate Flora and Fauna into different natural systems, but an ecosystem in equilibrium must include both. Ungulates (grazing animals) that once roamed the plains would graze and trample the prairie, essentially doing our spring cutback over the winter. If you have access to grazing animals like cows, sheep or pigs, allowing them to graze is probably the best option for cutting back our plants. Too bad it is not an option for most of us!

Fresh Baguettes and Healthy Soil

Fresh Baguettes and Healthy Soil

By Johnny Moore

Prairie diversity above and below ground. Image Source: Tall Grass Prairie Center

January 15, 2024

Soil, like a baguette, is little more than a few raw ingredients mixed together: minerals, living and decomposing organisms, water, and air. But a fresh baguette in Paris, though made from simple ingredients, is far from simplistic. The same is true of healthy soil. A baguette is the masterful suspension of flour, water, and salt, shrouded in an idyllic crust, wrought by the living organisms of yeast and the hot air of an oven. The well ordered ingredients produce a work that is nothing shy of beauty and harmony. An authentic, French baguette, eaten fresh, is irresistibly delicious, nourishing to mind, body, and soul. It is magical.

While it’s rather easy to care about a good baguette, who cares about the soil? Just sprinkle on some fertilizer and things should be fine, right? If there is a weed here or there, just apply the right herbicide and you will be set. What more is there to it?

By the same token, we could scrap baguettes and just eat power bars, chocked full of all the essentials. Eat nothing but your favorite power bars and it doesn’t take long to miss the magic that food like baguettes offer. We desire more than the perfect ration of vitamins and nutrients delivered to us in a compact, scant, industrialized bar. We long for real food.

If you’ve ever tried to push a shovel into rock hard clay, or questioned why your tomatoes developed a blight from the soil, or why your grass is turning brown even though you’ve been watering it twice a day, the answers likely lay in the health of your soil.

Like a baguette, healthy soil can be magical–causing plants to grow and thrive, being easy to dig, free of weeds, and absorbing water like a sponge. However, as the raw ingredients of a baguette need a baker to proportion and bake them, the soil needs its many members to order and organize it. Without those processes in action, we are left with the stubborn, raw ingredients, unyielding to our shovels and unhelpful to our tomatoes. Who are the bakers of the soil world? It turns out there are more than we have yet been able to classify. 

In healthy soil, the raw ingredients are orchestrated and processed by innumerable microscopic life forms. These microbes take the raw ingredients of decaying biomass (dead plants, leaves, trees, etc.), minerals, water, and air, and bake the stuff we love and call topsoil. These “bakers” are bacteria, fungi, plant roots, and even animals. They take the raw ingredients in the soil and transform them into life-sustaining, bioavailable nutrients (think baguettes!) for one another and plants. Left to themselves, most minerals and elements are not in a form usable by plant roots and organic matter breaks down incredibly slowly. Plant your tomatoes in rocky or heavy clay soil, and though rich in minerals, your tomato roots may struggle to break down the rock and clay to access and take up the phosphorus, potassium, or nitrogen the plant needs to produce delicious fruit. Plants need the raw ingredients turned into a bioavailable form.

As we know, plants transform sunlight and carbon into organic matter. Plants convert the solar energy and release substances through their roots known as exudates–organic compounds which attract and help foster various bacteria and fungi in the soil. Those bacteria and fungi are the bakers and doctors, feeding the plant the nutrients and medicines it needs to grow and fight off pathogens. This is the beginning of what’s known as the soil food web.

A plant in need of phosphorus secretes root exudates attracting bacteria that can make phosphorus bioavailable to that plant. The bacteria form a relationship with plants which feed them; the plant receives the nutrients it needs from the bacteria while the bacteria feast like kings. As the bacteria thrive, they become the food supply for other soil organisms: bacteria are eaten by protozoa, protozoa are eaten by nematodes, nematodes are eaten by arthropods, arthropods are eaten by birds and small animals. The entire food chain is supported by plants living in the soil.

Vibrant and full of life, healthy soil becomes sponge-like, able to absorb inches upon inches of rainfall, staving off erosion, drought, and flood. Contextualized plant communities are then able to thrive, support themselves and the surrounding ecosystem without supplemental irrigation or fertilizer inputs and with minimal stewardship management. And just as with baguettes, the world of the soil, freshness and abundance, becomes a beautiful and magical place. 

2023 Plants of the Year

By Michael Erickson

December 6, 2023

With plants at the forefront of most of our designs at Tree of Life, a select few always stand out to us at the end of our planting season. We are constantly looking for new species and cultivars to utilize in our designs, and we wanted to share our top five favorites from the past year. 

Eragrostis spectabilis

One of our favorite grasses to use this year, Eragrostis spectabilis or purple lovegrass is a gorgeous warm season grass, with a vibrant purple inflorescence. Tolerant of a variety of conditions including drought and heat, Eragrostis thrives in many native inspired and xeric gardens, offering a native and earlier blooming supplement to Muhlenbergia reverchonii. With such a delicate seedhead, its smoky texture billows when planted in droves and feathers into its surrounding plants. Given its aptitude for the Colorado landscape, it readily self-seeds to fill in empty spaces in the garden without displacing the less competitive plants. Altogether, Eragrostis spectabilis is well-equipped for our climate, it has a dynamic growth pattern, and provides a delicate but colorful texture to the garden. 

Artemisia abrotanum ‘Leprechaun’

Texture is a key piece in our designs and the discovery of the Leprechaun Artemisia has provided us with a great new texture that will thrive in multiple conditions. It is dense and compact, with a lime green color and a feathery, fearn-like texture. With tree growth, garden maturity, or general change in the garden, we want to use plants that will thrive even if their conditions change and the Leprechaun does just that. With its rigid form, we have utilized this artemisia as a structural element in our designs, similar to that of a boxwood without the water requirements. Tolerant of sun and shade, and low moisture, we look forward to seeing it mature in our gardens from this past year, and to using it in designs in the coming years.

Atriplex canescens

Sometimes referred to as Chamiso or Fourwing Saltbush, Atriplex canescens is a true native to the great plains. With an ambiguous form, Atriplex may grow low to the ground and spread, or may remain more compact and take a traditional shrub form. Silvery foliage throughout the growing season produces fruits that have four wing-shaped seeds giving Atriplex its common name. We love its unique seed head and irregular growth pattern and have used it intermingled with shorter grasses. Tolerant of a variety of soil conditions especially high-stress areas and requiring very little water, Atriplex is a staple plant for high stress and low water environments. 

Dalea purpurea

Year after year we continue to be amazed that Dalea purpurea or Purple Prairie Clover is a native plant and not cultivated specimen with its bright purple thimbles and fanciful appearance. Prairie flowers are often considered insignificant or underwhelming, but Dalea purpurea packs a punch in its relatively modest form. Growing in a vase shaped form, exploding into fluffy purple puffs. Beyond floriferous interest, Dalea purpurea’s foliage is needle like, offering textural interest even before its bloom mid summer. Blooming around the same time as Asclepias tuberosa, we love the intense variation of color and form.  As a member of the Linaceae family, a long taproot and mycorrhizal fungi below the surface increase the soil health of the landscape. 

Liatris ligulistylis

Yet another rather flamboyant prairie plant, L. ligulistylis, sometimes called Meadow Blazing Star, maintains all the features of the genus but its flowers are much more conspicuous than its other native cousins like L. spicata. Growing up to five feet tall, bright fuchsia spikes stand out not only to us, but also and especially to butterflies and pollinators. We love utilizing this liatris as a strong vertical accent in our gardens, towering over shorter perennials.  A vibrant and floriferous native plant, this Liatris brings height, dimension, and fun to many of our designs.

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