Soil Series #4: What Weeds Can Tell Us About Soil Health

Soil Series #4: What Weeds Can Tell Us About Soil Health

When most people see weeds in a pasture, the first reaction is usually frustration.

But on a regenerative farm, weeds often tell a much more interesting story.

Instead of seeing them only as a problem, we try to look at weeds as soil indicators — plants that reveal what’s happening beneath the surface.

Over the past few years at Dos Lobos Ranch, we’ve started paying closer attention to the plants that show up in different parts of our pasture.

And those plants have taught us a lot about our soil.

Weeds Are Nature’s Repair System

Many pasture weeds appear when soil conditions need correction.

Some plants grow where soil is compacted.

Others thrive where the ground has been disturbed.

Some appear where fertility is low or where the soil surface is exposed.

In other words, weeds often fill ecological gaps.

They are nature’s way of stabilizing soil until more permanent plants can take over.

Reading the Signals

As we’ve improved our grazing management and soil health, we’ve watched different plants appear and disappear in predictable stages.

For example, in some areas we initially saw plants like ragweed, wooly croton / dove weed, bull nettle, thistle, sandburs (stickers) and horseweed / mare's tail.

These species often appear where soil has been disturbed, is compacted, or where pasture cover is thin, not necessarily nutrient deficient.  

The seeds germinate because the soil is too hot.  Get the grass going in thick and tall, and it will shade these out.  Bale grazing in the winter will help control these come the next growing season as well.

As soil conditions improve and grass cover increases, these plants tend to decline naturally.

Signs of Recovering Soil

As our pasture biology has improved, we’ve also started seeing other plants that indicate soil is moving toward recovery.

Some plants appear when soil structure begins to improve and root systems start rebuilding.

In these cases, weeds are not the enemy — they are part of the transition signal.

They help:

• protect bare soil from erosion
• add organic matter through their roots
• break up compacted soil layers
• create shade that helps soil life recover

Over time, healthier pasture grasses gradually replace them.

Why We Don’t Spray

Many conventional pasture systems respond to weeds by applying herbicides.

While herbicides can remove the visible plant, they don’t address the underlying soil conditions that allowed the plant to grow in the first place.

If the soil problem remains, the weeds often come back.

Instead, we focus on improving the conditions that favor healthy pasture:

• building soil organic matter
• improving grazing management
• maintaining ground cover
• encouraging soil biology

As those conditions improve, many weeds simply lose their advantage.

Control Through Grazing

Letting these species get out of hand can slow the progress of grass coming in as most of these get tall and shade it out before the grass has a chance to get established.  Utilizing rotational grazing and multispecies grazing helps to manage these weeds, too.

Cattle will graze thistle flowers (ours LOVE them), goats will eat the prickly leaves in a heartbeat.

Pigs LOVE wooly croton, goats will graze the flowers before they go to seed in the fall, but leaves will cause diarrhea in goats if they eat too much.

Goats LOVE horseweed / mare's tail and will strip the leaves from it before you can blink.

Bull nettle... well, we get the shovel out for those if they get out of hand.  

Bale grazing during the winter on trouble spots where any of these species pop up will help curb the return the next spring.

Tightening your rotational grazing to a smaller section at a time if you're running just cattle will force trampling and sometimes cattle will learn to prefer certain species.  Many of them are actually very nutritious for livestock, such as ragweed.

Watching the Land Change

One of the most encouraging things about regenerative farming is seeing how plant communities change over time.

As soil improves, the pasture gradually shifts toward stronger grass growth and fewer opportunistic plants.

It doesn’t happen instantly, but the trend becomes visible over several seasons.

Watching that transition unfold is one of the most rewarding parts of working with the land.

A Different Way to Think About Weeds

Weeds aren’t always a sign of failure.

Often they’re a sign that the soil is trying to heal.

By paying attention to what plants appear and where they grow, farmers can learn a lot about what the soil needs.

And when we focus on improving the soil itself, the pasture begins to correct many of those problems naturally.

What’s Next in the Soil Series

In the next post, we’ll talk about one of the most important tools we use to rebuild pasture health:

Rotational grazing.

It’s one of the foundational practices behind regenerative livestock farming, and it plays a major role in helping soil, plants, and animals work together as a system.

— Dos Lobos Ranch