Soil: We Need to Stop Treating it Like Dirt

Gardeners can improve their soil.

Why is soil important for gardeners?

We’ve all heard about growing the right plants in the right places so they’ll survive, but without healthy soil, your plants (even the right plants) will suffer or even die. So let’s look at what’s under our feet.

 (This article is an updated version of one I wrote for a garden blog several years ago, which is no longer available online.)

Healthy soil ecosystems are a complex interaction
 between bacteria, fungi, insects, & more.

Soil: the ecosystem beneath our feet

Soil found in native habitats is a complex ecosystem of bacteria, fungi, nematodes, earthworms, ants, salamanders, toads, insect larvae, moles, and more, all living in a substrate of minerals and humus. The minerals are a mixture of rocks, sand, silt, and/or clay. The humus or organic matter consists of fully or partially digested plant and animal parts. As humus is broken down into simple compounds, it provides a living for the decomposers, and eventually yields nutrients for plants. 

One gram (about 1/5 teaspoon) of healthy, non-poisoned soil could contain one hundred million bacteria, one million actinomycetes (a filamentous bacteria), and one hundred thousand fungi; if strung together, their filaments or hyphae would measure about 16 feet (5 meters) in length. This same gram of soil could also contain hundreds of nematodes living on the damp surfaces of the soil particles and maybe a few insect eggs or larvae and some earthworm cocoons. The exact proportions of each of these organisms will depend on soil conditions such as moisture, acidity, aeration, amount of humus, and the local plant community growing in the soil. 

A Quest for a Perfect Lawn: a Case Study

This graphic makes the point about how
out-of-step people are for trying to
maintain unnatural&unsustainable lawns.

To celebrate Earth Day, this post is about rethinking the "perfect" lawns, which are maintained with applications of fungicides, insecticides, herbicides, synthetic fertilizers, and never allowed to go into seasonal dormancy. In Florida winter-dormant grasses are over-seeded with cool-weather grasses, irrigated through the dry season, & fertilized. 

Today's lawn expectations go way back to how European formal gardens & lawns around castles and manor houses were kept to show others how wealthy the owners were.

Today, lawn-"care" organizations can make lots of money by encouraging homeowners to have "perfect" lawns, but does it make sense or cents? As a botanist, naturalist, and a sustainable gardener, I would say, "NO!" 

There are so many reasons for replacing most of your lawn acreage with unpoisoned native habitat & pollinator gardens and then freeing the remainder of your lawn from all pesticides & synthetic fertilizers, mowing it less often at the highest setting, letting it go dormant in the winter & allow a variety of plants that tolerate mowing to grow there.

It's Time to Think Globally, but Act Locally.

www.climatewiselandscaping.com 

Climate change is real!

We are seeing its effects on the weather with more frequent, stronger and slower-moving hurricanes, more severe droughts, more fires, and rising sea levels. But Sue Reed and I did not debate the reality of climate change or what has caused these rapid changes when we wrote our award-winning book, "Climate-Wise Landscaping: Practical Actions for a Sustainable Future." Instead we said, "Let's roll up our sleeves and get to work."

The same thing has happened in the writing of my 7th book with the working title "Living Shorelines for Florida: A Practical Guide for Building Resilience," which will be published in 2025. I and my three coauthors did not debate sea level rise or discuss what the causes might be, but plans for dealing with rising sea levels are included in our various actions and designs for more resilient shorelines.

So what actions can we take and will it make any difference?

While actions we take in our yards and in our communities may seem insignificant, there are many millions of homeowners and communities, and together, we are a powerful force. What follows are some ideas and links to resources for some of the most significant actions. 

Two weeds: one native and one nonnative

While the sharp, hard spikes
 on the seeds hurt our feet and
embed themselves in the
lawnmower tires, this is their
method of dispersal. 

Sand spurs

Six species of sand spurs or sandburs (Cenchrus spp.) are native to Florida. They are true grasses in the grass family, Poaceae.  While native plants are highly recommended for sustainable, climate-wise landscapes, these are not desirable because of the hard and very sharp prickles that cover their seeds. 

They have volunteered in our yard only out by the road where the other plants in our freedom lawn are a bit more sparse and where the neighborhood dog walkers visit on a regular basis. So even though I have cleared out this population of annual plants before, new ones can get a start out there when dogs bring more seeds from elsewhere.

Winged sumac, a useful understory shrub

A small winged sumac in bloom, which
attracts a wide variety of pollinators.

Winged Sumac (Rhus copallinum) is a deciduous, compact, densely growing, colonizing shrub that is native to all of Florida and the eastern half of North America. It can grow to 10 to 25 feet tall and nearly as wide, although the ones in our yard are much smaller than that. They will grow in a wide variety of situations, but they do best in full sun or partial shade and require good drainage. 

This plant could be used in a hedge row with a variety of other shrubs and is a good choice for naturalizing at the edge between wooded and open areas. Keep in mind that it will be bare for a few months in the winter. It can spread quite some distance via rhizomes or underground roots, so keep that in mind when choosing planting sites.

Ohio Spiderwort: a pollinator-friendly native wildflower

A small fly-like bee was pollinating this flower.

Bluejacket or Ohio spiderwort (Tradescantia ohiensis) is native to most of Eastern North America and to most of Florida. It attracts pollinators, especially bees. Each day, one or two flowers bloom in each flower head. They open early in the morning and then wilt in the afternoon. Each flower head contains twenty or more flowers and new flower heads are formed throughout the long season from early spring to late fall. There is a long blooming season.

There are three other species of spiderworts native to Florida: hairy spiderwort (T. hirsutiflora), longleaf spiderwort (T. roseolens), and zigzag spiderwort (T. subaspera). But the bluejacket has the largest native range and is the one that's most readily available from the native trade.

Spiderworts are monocots and are in the Commelina family (Commelinaceae), which includes 36 genera world wide, but only five occur in Florida. "Spiderwort" refers to the sap which dries into web-like threads when a stem is cut.

Why talking about native plant landscapes is so important

Consumers are presented with this array of mostly
nonnative plants in full bloom to plant so their yards can
decorated with plants at peak bloom all the time.

Where are the native plants?

New homeowners and beginning gardeners find displays similar to this photo that I took at a big box store a few years ago. It's filled with mostly nonnative annuals in full bloom. Each tray is not too expensive, but after they fade in a couple of months, people are expected to come back to replace them with the next set. 

Examples in garden magazines and gardening TV shows with their instant landscapes imply that garden installations are events, and not ongoing projects that develop over the years.

The hand of the gardener in native landscapes

Plant more natives!

In 2013, a volunteer beautyberry shrub near the edge of the
lawn is surrounded by several water oaks.

Ecologists and environmental organizations have been urging people to plant more native plants, to build bird-friendly and pollinator-friendly habitat, and to do this by removing at least some of their lawn.

One prime example is Doug Tallamy's HomeGrown National Park where you can register your yard to be part of of this park by replacing at least half of the lawn with native plants.

This is great and I hope that millions of homeowners and other property managers take this step to build native habitat, but there are some important steps to take, especially in urban and suburban areas, to increase the acceptability of these native landscapes. Our yards and our community landscapes, even if they have a good portion of native plants are not wild spaces and will need some regular care. (Actually, I wrote a book on this topic. See below.)

Habitat gardening

In natural areas, the soil ecosystem supports the plants,
which support the insects, which in turn support
the birds and other wildlife.

Florida's default landscapes

Most yards in Florida consist of highly maintained monoculture lawns, a few stand-alone trees, and a fringe of foundation plants around the buildings. This is the opposite of habitat gardening because typical Florida lawn care includes regular landscape-wide applications of insecticides, herbicides, fungicides and other poisons. Then since these pesticides are not good for the turfgrass, synthetic fertilizer is applied to keep it green.

This treatment damages the soil ecosystem (shown in the poster here), which plays an important role in keeping the plants healthy, which then support the insects and the birds. In addition, much of the lawn chemicals have rinsed through the soil or have been carried away with erosion to pollute our waterways causing too much algae growth and toxic dead zones.

Tall elephantsfoot, an easy-to-grow Florida wildflower

A Great Purple Hairstreak sipping nectar from tall
elephantsfoot flowers. The larval host for this beautiful
butterfly is mistletoe (Phoradendron leucarpum).

Tall elephantsfoot (Elephantopus elatus) is a perennial Florida native wildflower with leathery leaves that form a rosette around its central growing point at ground level (basal leaves) and it's this leaf arrangement that inspired both its common name and genus name, elephantsfoot and Elephantopus, because they form a dense circle shaped like an elephant's footprint. The plant produces one or more tall, hairy flowering stalks with hardly any leaves. 

It's a member of the daisy family (Asteraceae), but it's unlike many of the family members that have flower heads composed of both disk and ray florets like a sunflower (with the ray florets looking and acting like petals and the smaller disk florets arrayed in the center). The flower head for this species has only disk florets that are subtended by three hairy bracts, which define the shape of the flower head as a triangular. The florets are light lavender to whitish and last only a day. They don't bloom until late morning just when the pollinators are first becoming active. So if you're out early in the morning, all you'll see are the old flowers from the day before.

Our freedom lawn

We let our lawn go wild!

When we first moved into our house, the lawn-care guys who had worked for the former owner stopped by to offer to continue their services. When I refused, they said that without their poisons (fungicides, insecticides, and herbicides) and their specially-formulated fertilizer and weed & feed applications that our lawn would die. Well, as it turns out, a few months later some brown spots did develop, but they were soon taken over by other plants, which those lawn guys would probably have condemned as "weeds."