WHY MANY AMERICAN GARDENS ARE FULL OF MULCH?

Posted by Radovan Hajek on Feb 08 2025

It’s always wonderful and useful to visit gardens. To see how plants are combined, how the plant needs are met or not, or how the plants perform. If they are pushed to their limits, still manage and why so. How the growing strategies are knitted together, if the color palette tunes well. There’s always something new to discover and learn, even if you see mistakes or early stages of establishments.

I’ve traveled and visited many gardens in Europe and the Midwest. I saw incredible gems, some average gardens and some bad ones too.You’ll find this mixture of gardens everywhere in the world, so this is not a big deal.

What I have noticed in the eastern part of USA is very loose planting schemes. This pattern is so widespread, I wouldn't hesitate to call it a “cultural feature”. I don't know if there's much to learn from it. Maybe learn how not to garden.

"As you walk down your block, drive through your neighborhood, travel from city to city and state to state, you will notice most perennials are living in the sea of wood-chip mulch, irrigated at least three times a week for twenty minutes - or not at all. Most of these plantings will have large empty areas. The uninhabited areas were planted originally, but the plats eventually died. What caused so much decline?" Roy Diblik, The Known Maintenance Perennial Garden, 2014 ©US Perennials

I find large and heavily mulched areas disturbing. My professional view might be “a bit distorted”, but I will always value higher any planting filled with plants and with many mistakes, wild ones, or gardens with too many colors over the “mulched gardens with a few crouching plants”. Unfortunately these picture are way too common - public spaces, parks, campuses, private gardens,....and most people probably overlook this. There's something rotten in the States. Both pics above - public spaces at the Muncie Hospital. ©US Perennials

Public space with small plants (Veronica spicata - Speedwell and Sedum sp. - Stonecrop) that are drowning and declining in the mulch. Mulch holds too much moisture for these drought tolerant plants, their crowns are rotting. Picture was take a few years ago, and those small plants are gone by now. Shrubs, Calamagrostis x 'Karl Forster' and mulch persist. Mulch persists because it's added in abundant quantity every or every second year. Such a amounts of mulch choke many plants to death, some will survive (Iris, Peony, Hosta), many will struggle. Bloomington, IN. ©US Perennials

Sparse plantings don’t ignite many emotions. What’s more, they are not functional – they don’t persuade the owners to spend more time outside, to live in their gardens and they hardly provide habitat for wildlife. Mulch became more important than the plants themselves. Plants are the minority, spaced about 2’ apart. They will never touch, intermingle, grow together and will never create harmony, contrast or drama. They’ll just live their separated, sad and struggling lives. More plants have to be added here.©US Perennials

Picture from the same garden. To put things right and with all the respect to the homeowners - this garden is actually loved and well maintained, and the owners spend a lot of time in their garden! The trouble is the compact dwarf plants - dense mounded shapes add to the general tidy and neat look. But those plants can't add height, they can't intermingle and if they touch they'll form a uniform mat. Compact and short plants are great sellers, they bloom and look good in gallon pots. Box stores and even garden centers know it, and customers can get easily persuaded to purchase these. Dwarf plants are good for edges, but they can't be the only type of plants in the bed, they can do only so much. Adding a different shape = airy, upright grasses like Schizachyrium (Little Blue Stem), Muhlnebergia capillaris (Pink Muhly Grass), shorter cultivar of Panicum (Switchgrass) or Gaura, Verbena bonariensis, Gompthrena etc. would change the whole look and feel. Pic taken at Garden Walk 2023, Bloomington, IN. ©US Perennials

A few survivors in the flower bed at Muncie Hospital. There are no weeds, but also nearly no plants, the bed is neat and tidy. Accepted norm by the facility and the public.©US Perennials

Empathy with plants

Only a few years back, Covid-19 forced us to change the game. We had to keep social distances everywhere, relatives were not allowed to visit their elderly parents. Those were disastrous times for social creatures like humans. But plants, just just like us, are social beings and have developed in communities for millions of years. So why do we torture them by social distancing? With distant plantings, we don't make them happier or healthier. How do those plant feel?

(Picture copyright : 1 - What we know about social distancing, healthmatters.nyp.org. Pic 2 - Protect yourself from the novel coronavirus ref guide, Internet)

Social distancing of smaller cultivar of Pennisetum (Fountain Grass). Spacing here is 4.5' ( with those vanished ones, the spacing is 9' apart). Whoever planted (and mulched) this bed committed "horticultural" crime. Fast food restaurant, Indianapolis

Geum (Avens) and Heuchera (Coralbell) at the entrance to a daycare facility 2 years ago. Some dark-leaved coralbells are already declining in too thick layer of mulch. Now 2 years later, those are gone and most of the Geums look miserable too (Bloomington, IN). ©US Perennials

Non-organic mulches such as gravel, river rock, haydite, and sand, are alternatives to the classical organic mulches. They also carry the same troubles - huge gaps and large spacing. Crown rot doesn't occur here, but overheating does. Hard surfaces become very hot and cause the surroundings to become warmer and then stresses plants. In the cities we can call it creating a "heat island" or "desertification). Southern Indiana. ©US Perennials

Crushed rocks, just like any organic mulch, are supportive material, and should be eventually covered with plants. Small compact plant in small quantities will never fill in. Bloomington, Indiana. ©US Perennials

Such a distant plant display is not natural and reminds of artifact display in an old museum. And yes, there were times, when plants were grown in somewhat similar way. When revolutionary book of William Robinson – The Wild Garden (1870) introduced naturalistic looking planting. Plants slowly left the prison of formal settings and gained some freedom.

Illustration from 1880 William Robinson's book shows very natural looking and eye-pleasing garden with colonies of Narcissus poeticus, and Broad–leaved Saxifraga, etc.continuously transitioning to a woodland edge with shrubs and trees (English park scenery). Wikipedia

Picture from another William Robinson's book called " The English Flower Garden" (1883). Edge Hall, Malpas, Cheshire. Lawn garden with hardy flowers in beds and groups, engraving from a photograph.

"In The English Flower Garden, Robinson laid down the principles that revolutionized the art of gardening. Robinson's source of inspiration was the simple cottage garden, long neglected by the fashionable landscapists. In The English Flower Garden he rejected the artificial and the formal, specifically statuary, topiary, carpet bedding, and waterworks—comparing the modern garden to "the lifeless formality of wall-paper or carpet."

The straight lines and form in many gardens were seen by Robinson to "carry the dead lines of the builder into the garden." (page 12, The English Flower Garden) He admired nature's diversity, and promoted creepers and ramblers, smaller plantings of roses, herbaceous plants and bulbs, woodland plants, and winter flowers." (Wikipedia)

The picture shows "transitional phase" where plants were still grown as single individuals or in small groups, with mowed lawn around these. This phase lasted from the end of 19th century to about early 20's of 20th century, depending on the location. In central Europe such plantings were called "Kvetnice" (which could be maybe very freely translated as "orchard of flowering plants", or "living catalogue").

SELMA KNEW

Selma in The Garden, around 1915-1920, Theodore Clement Steele. ©TCSTEEL.org

The famous American impressionist painter T. C. Steele (1847–1926) moved with his wife Selma to very rural Brown County, Indiana. Often he painted his wife Selma's garden. Selma was a self-educated gardener, city girl from Indianapolis, who learned everything from scratch and became an avid passionate gardener. Selma gathered and read every gardening book and magazine that was available. She actively exchanged knowledge with Purdue University and collected many flowering plants. As you can tell from this painting, her garden is filled with plants! It's green, it's colorful and beautiful. Back then mulch in the way we know it now, didn't exist. Gardeners would add some organic matter or manure to provide nutrients, to improve the plant growth and health. Selma filled her garden with flowers.

Selma Steele wasn't the only one. Especially German settlers created gardens full of plants, reminding of natural areas (back then there was plethora of wild nature). Those gardens often made the boundary of where the garden ends and nature begins, very blurry (freely translated from my favorite author Vaclav Cilek and his book The trees call me my name - Stromy me znaji jmenem). Eventually those types of gardens disappeared, just like the wilderness.

BACK TO THE 21ST CENTURY

Any reminiscense to the previous texts...? ...the straight lines that W. Robinson commented in 1883 as "carry the dead lines of the builder into the garden." (Wikipedia) 1 - ©Redfin, 2 - ©US Perennials

Yes, far too many American gardeners, landscapers, landscape architects and designers are stuck in the past and follow this over 100 year old transitional phase of flower gardening = regular spacing in lines, separated and distant plants. "Overmulching" is a new invention, but not a good one.

Uniform and sterile new suburban neighborhood in Indianapolis (or anywhere in the Midwest or USA). How many of the new homeowners will turn into gardeners? Will they spend some time outside? Or will it be another wasted luxury of owning a piece of land and do nothing with it? If HOA allows, will they become "gardenowners", or are they destined to be "yardowners" with conventional mow & blow, mulch & shear practises? ©Zillow

Before we move on to the solutions and good examples, lets sum up why we're stuck here:

Poor knowledge of plants and how to put them together. I have a chance to briefly talk to a few graduates from Purdue University (Landscape design program) and they agreed that the students don’t learn much about plants during their studies. But how can the gardener design gardens, if they don't know their plants?
Loose plantings are maintained by not knowledgeable crew of landscaping companies. Distant separated plants can be easily recognized and identified, and any worker can pull weed or apply herbicide and around those planted plants
Lack of good examples of public gardens/botanical gardens that would educate and inspire. Public is not exposed to seeing dense plantings and abundance of loose plantings can’t create higher expectations. Garden owners will be satisfied with very similar gardens that can see in their neighborhood.
Homeowners don’t garden themselves, spend little time outside or don’t care much about their yards. Mowing & blowing might be the only activity they are willing to do or pay for.
Plants have shorter lifespan and only the toughest ones persist. Plants that die and disappear are never replaced. What persist are bare mulched spots or large mulched areas
Tidy and neat areas contrast with the wild = uncontrolled, potentially dangerous and scary. Native plantings seem to be often the only dense plantings, but in many cases lack stronger design (or least structural contrast) and end up looking too wild/messy and therefore refused by the general public. Any neglected areas quickly turn wild with many saplings of trees and shrubs (in Midwest they will eventually turn into woodland, unless they are repeatedly disturbed).
Prevalence of short, compact and dwarf plants on the market. Compact plants are great sellers, they transport easier, flower and look great in pots. And plant breeders know that and focus on introducing more and more compact plants. But these new cultivars often loose some vigor, stay smaller, don’t add height, usually don’t spread much to fill large gaps
Shrub shearing, early clean ups and regular mowing are very common techniques and add up to the demand for “tidy & neat”
Financial reasons – bed with lots of plants can be pricey, but they don’t have to be. You can plant more smaller plants, divide older clumps, share plants with neighbors, or sprinkle some cheap annual seeds into the gaps
Laziness, low expectations and little will to learn and improve

SOLUTION IS SIMPLE = LESS MULCH, MORE PLANTS!

Claudia West, partner at Phyto Studio (with Thomas Rainer) is right. Both are also co-authors of wonderful book "Planting in a post-wild world". The solution is simple, but we need the knowledge and good examples to follow. Both authors say that the much needed shift from current planting paradigma to plant communities paradigma will be the biggest challenge. ©Claudia West

The best is to look at nature, how plants are naturally organized and grouped together. Nature covers the soil surface with plants. The only sparse vegetation will develop on "extreme" sites like on pure sand, on rocky soils (goat prairies), that lack moisture or the moisture quickly disappears. Kankake Sands ©US Perennials

Plants in nature mulch themselves with their own debris and with leaves. Here the wind brings the oak leaves from the surrounding woods. The closer to the trees, the thicker the leaf layer is. That is how nature is mulching plants. The open areas had to be browsed, occasionally burned or mowed for hay (or humans have to step in to block the succession towards the woodland community). Notice the plant density on the right picture - there can be dozens of various sized plants on 1 square ft. In garden conditions, we don't have to plant that densely - usually 0.7-1 plant per 1 square is enough, but if we don't choke plants with mulch and allow the plants to selfseed, we will end with quite a few plants per 1 square ft. Pictures taken in semi-natural prairie in Bloomington, IN in early May. ©US Perennials

The same prairie in the middle of July. Many of us see this as a garden, many of us get inspired. Such a look is achieved by 30 years of consistent suitable management. Plants here compete and support one another, they touch and live together in healthy plant community and in intimate relationships. ©US Perennials

A neglected front yard provides a lot of ecosystem functions, but won't be accepted by the general public. Most people will see this as a weedy yard. Wilderness usually bothers us, especially in the places where we don't expect it. But if we insert our intention and add some coneflowers, rudbeckias and structural plants (Eryngium yuccifolium, Yucca, etc.) we have a wildflower garden. But even wild areas have to be maintained - tree and shrub sapling will swallow this area very soon. Still such a place has a much higher value than mowed turf. Bloomington, IN. ©US Perennials

For many homeowners, the solution could be fairly easy - by adding plants to the current shrubs and stay on the top of it. Just planting more densely and mulching lightly (ideally with partially composted or shredded leaves), so plants don't choke and can spread and thrive. In simple drawing are present from the tallest in the back to the front - Phlox paniculata, Agastache 'Blue Fortune', Rudbeckia 'American Goldrush', Calamintha nepeta, Schizachyrium scoparium, and the shortest Allium 'Summer Beauty' and Sesleria 'Greenlee'. The drawing represents mid summer look, in reality a few spring plants and warm season grasses would be beneficial for all season interest. Bloomington, IN. ©US Perennials

Snapshot from James Hitchmough's Youtube talk - advanced approach of creating dense and multi layered (and long flowering) garden. The public may not be ready for such an approach ©James Hitchmough

Shade garden - this is how much bark naturally peeled off the mature black walnut tree. Sycamore trees will shed a lot more pieces of bark per season, just like dead trees, but it's never several inches thick layer. Bark/woodchips mulch creates conditions that are not natural for herbaceous plants. That's why too thick layer of organic mulch can kill and stunt many perennials. The black dirt on the surface are fully decomposed leaves. ©US Perennials

MULCHING AND DENSITY SUMMARY:

Any mulch is only a supportive material. It suppresses the weeds, holds the moisture, can enrich the soil life. BUT visually should be dominant only in the early years before the plants establish, get bigger and fill in (or in early spring when you top the area with thin layer of mulch).

The goal is to fill the area with plants, not with the mulch:

plant more densely and let your garden be plant driven and not mulch driven
use thinner layer of mulch or even better mulch with leaves (shredded, partially composted or whole leaves)
mulch with the plant debris – cut down your flower bed in pre-spring and then mow over the debris several times
combine all of the above techniques
If you’re not gardening yourself, choose a designer/landscaper that plants densely - check their portfolios and websites. It may take a while, since majority of landscapers still plant very sparsely.
For most of average sized perennials (1-2’ tall x 0.5’-1 wide) plant about 12” apart (from center to center of each plant).
Taller and wider perennials 14-18” apart (from center to center). Very large or suckering plants even more.
General rule in the words of square footage – plant about 0.7-1 average-sized plant per one square foot. That means for a 100 square ft garden you will need 0.7x100 = 70 plants. If you plant 1 plant per 1 square ft = 1x100 = 100 plants. Some people, and nature, plant even more densely - but this approach is reflected in the look and maintenance.
use ground covering plants and fillers
Roy Diblik - how to use plant debris for mulching (no bark or woodchips needed)
Roy Diblik - planting large gravel mulched garden in Argonne National Laboratory, Aurora, IL

Partially decomposed leaves are ideal for mulching herbaceous plantings, where plants are placed densely. Leaves are the natural fertilizer, improve the soil, but don't over fertilize plants (= weak stems, flopping). They can decompose quite quickly, so you have to keep adding them until the plants fill in. ©US Perennials

Transferring the design drawing from paper to the site, marking the groups with white spray and placing the plants ©Andrew Marrs Garden Design

Dense placement at Iowa University. Planting big plants in gallons requires decent budget, but plants mature and fill in a bit faster ©Austin Eischeid Garden Design

Shade garden - transferring the design to the site, using string grid and spray. Here, the designer used only a few slower plants in gallons (fern and hellebore), the majority were plants in 3.5" pots and landscaping plugs. Smaller plants usually bulk up quickly and the cost of the plants is much lower ©Andrew Marrs Garden Design

Naturalistic backyard garden, mostly planted and then mulched with the partially composted leaves ©Andrew Marrs Garden Design

Sand mulched flower bed "Arrowhead" at our US Perennials nursery in mid spring 2022. Area was mulched with about 1.5" of coarse sand. It perfectly suppresses the weeds, because the surface has no nutrients, dries out too fast or gets hotter. The disadvantage of this is that you tend to clean it up more, because debris doesn't look that good on the sand. No organic matter eventually leads to some stunted plants (the soil here is also quite lean). So we ended up leaving debris here and adding nutrients with the leaf mulch - this organic layer does decompose during the season and doesn't really build up. With this compromise, some weeds appear, but still this is a very low maintenance bed and a dramatically changing bed during the year. Now it is more filled with plants that self-seed. ©US Perennials

Densely planted garden in April mainly from landscaping plugs (12" apart) filled in completely by the end of summer of the same season. Plugs or plants in smaller pots are a lot more cost effective. Smaller plants behave like teenagers who are eager to become quickly adults. Mulched with composted leaves after planting. New Hope for Families, Bloomington, IN ©US Perennials

MAY YOUR GARDEN BE PLANT DRIVEN

There is a lot of good examples and it's impossible to show all of them. Here's work of some of my favorite authors or favorite places, and if you look carefully around you'll discover some too. These often have the "meadowy" feel, natural or better naturalistic vibe. This automatically comes with with the dense planting schemes and maintenance. Pics are a blend of smaller homeowner's gardens to bigger scale plantings for public and semi public spaces.

It's harder to find good examples of gardens that homeowners planted themselves. Mostly because you don't know where to find them. Random found garden with marvelous rural feel, Madison, IN ©US Perennials

Random garden find - narrow verge garden planted by homeowner. Not every garden has to have strong design patterns, filling the bed with plants we have available is good enough. How refreshing such an urban place feels! Madison, IN ©US Perennials

Garden Walk events are great opportunity to see private gardens, that you can't easily visit. This front garden wasn't part of the garden walk, but it stole the show. Refreshing look, lots of colors and pollinators, and people noticed it. This garden could easily beat some of the gardens that were shown. Bloomington, IN. ©US Perennials

Plant driven garden on the garden walk. It's simple - just fill your garden with plants you love! Bloomington, IN. ©US Perennials

Playful and partially random colorful planting in semi public space in little touristy place in Nashville, IN. The locals know, that flowering front gardens, flowering beer gardens, flowering verge stripes make the stay of visitors more enjoyable and the positive memories will bring the tourists back. Because in the Midwest we rarely see that, unfortunately ©US Perennials

Dense partially shade/shade planting with a few perennials (Hosta), filled with annuals. Downtown Bloomington, IN.©US Perennials

Dense mixed planting (annuals, biennials, leaf vegetables, herbs and some perennials) at Lily House at Newfields, Indianapolis ©US Perennials

Dense mixed planting (annuals, biennials, veggies, herbs and some perennials) at Lily House at Newfields, Indianapolis ©US Perennials

Edgerton Hospital in Wisconsin, designed and planted by Mark Dwyer and his team of volunteers. Healing gardens and hospital gardens are proven to be very beneficial for faster healing and recovery. In this case the hospital and it's gardens became a vibrant social hub. We need more of these! ©Edgerton Hospital

Edgerton Hospital Gardens have sections that are changed annually, but they are always amazing ©Edgerton Hospital

Irvin Etienne's tropical garden in rural area of Arlington, IN. Bold structures, hot colors and drama in dense, well layered seasonal plantings. Most of the tropicals are dug out and overwintered inside. Some surprisingly survive in zone 6b.©US Perennials

Irvin Etienne's tropical garden in early fall, Arlington, IN ©US Perennials

Janet Draper's Ripley Gardens, Smithsonian Museum, Washington D.C. Janet mastered the all year interesting look, where all the plants are welcome. Janet's goal is to slow down the visitors and make them notice the unusual beauty of plants. It is very hard to catch attention of the teenage visitors, but Janet with her style and personality is very successful ©Janet Draper

Wonderful smaller scale residential naturalistic garden, designed and executed by Andrew Marrs Garden Design. Bloomington, IN ©US Perennials

Narrow verge garden on average street in Bloominton, IN. Simple and very effective assortment and nearly no care with such a dense planting. All year interest, no mowing, pollinator friendly and serving many other functions. More of these in our streets please! ©Andrew Marrs Garden Design

Raynolds Road Garden - large scale naturalistic, well balanced garden in early May. At this time of year plants are growing fast and filling in. But before they will shade the ground, scuffing the weeds with push-pull dutch hoe is recommended. Andrew Marrs Garden Design, Bloomington, IN ©US Perennials

Two pics above - Benjamin Vogt's short grass prairie-inspired front garden. A very refreshing gesture in an otherwise very typical suburbia. The contrast of year round sterile turf yards and this constantly changing garden should be eye-opening for many. The turf gardens look the same all year round - boring and "dead", despite the fact they are green ©Monarch Gardens LLC / Prairie Up

Shade garden designed and planted by Benjamin Vogt. Using contrasting structures and leaf shapes is important for the times when nothing blooms. Native plants only ©Monarch Gardens / Prairie Up

Dense shade gardens in Millenium Park, Chicago with nicely contrasting structures. Designed by ©Austin Eischeid Garden Design

Shade garden with combination of arranged planted pots and plants in the ground. Designed by ©Jeff Epping Design and Consulting

Famous gravel garden in Olbrich Botanical Garden in Wisconsin. You can find pictures of this garden in magazines and books. Jeff Epping is working on new book about Gravel Gardening, that will be published by Timber Press in 2026 ©Jeff Epping Design and Consulting

Jeff Epping's own gravel garden at his house. With gravel or sand mulch, it is a lot harder to fill all the gaps. So those bare spots always shine some through the vegetation ©Jeff Epping Design and Consulting

Dunescape Residential project at Long Beach, NJ, planted in pure sand. Designed by Thomas Rainer and Claudia West and team aka ©Phyto Studio

Phyto Studio's public Bird and Pollinator Garden at Arboretum at Penn State. At this section of the garden is applied nearly restoration approach ©Phyto Studio

Phyto Studio - A Gardener's Garden. The dense and wilder looking parts always look good against clean line and tidy spaces or turf ©Phyto Studio

Brent Horvath's private meadow garden - calm, soothing and natural. Brent runs the renowned Intrinsic Perennial Gardens (wholesale nursery). It's pleasing to enjoy low maintenance garden after hard nursery work. Fontana, WI ©Brent Horvath, Intrinsic Perennials

Two pics above - Adam Woodruff's private garden in Boston, MA. No more words are needed. Designed by © Adam Woodruff Garden LLC

Two pictures above - Blank Performing Art Center at Des Moines, IA designed by Kelly D. Norris. Very dense interwoven matrix planting on steep slopes, with 140% coverage density (1.4 plant per one square foot. Pic from mid/late spring and mid/late summer 1 - ©Kelly D. Norris, 2 - ©Austin Hyler Day

There's no reason, why rather difficult places (like roof garden) shouldn't be planted densely ©Tony Spencer/The New Perennialist

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WHY MANY AMERICAN GARDENS ARE FULL OF MULCH?