How to read deficiencies in soil just by looking at weeds that grow on your land
If you want to improve your soil health and fertility, one of the easiest ways is to look at the weeds that grow in them. Weeds are not just annoying plants that compete with your crops or flowers, they are also indicators of the soil conditions and problems. By learning how to identify common weeds and what they tell you about your soil, you can take appropriate steps to amend and enhance your soil for better gardening results.
Why Weeds Matter
Weeds are plants that grow where they are not wanted or needed. They can cause economic losses or ecological damages by reducing crop yields, spreading diseases, harboring pests, or invading natural habitats. Some weeds are also noxious or invasive, meaning they are designated by government officials as harmful to public health, agriculture, recreation, wildlife, or property.
However, weeds are also nature’s way of repairing the soil for a more stable and healthy system. They can stabilize the soil, add organic matter, fix nitrogen, attract beneficial insects, or provide food and shelter for wildlife. Some weeds are also edible or medicinal for humans.
Weeds can also reveal a lot about the soil they grow in. They can indicate the soil type, texture, pH, nutrient levels, moisture content, compaction, drainage, or biological activity. By observing the weeds that grow in your soil, you can get a clue of what is going on below the surface and what you need to do to improve it.
How to Identify Common Weeds
The first step to identify symptoms of a soil by identifying weeds that grow in them is to learn how to identify common weeds in your area. You can use books or online guides that are targeted towards these plants, such as from The Old Farmer’s Almanac. You can also use apps or websites that allow you to upload photos of weeds and get identification results, such as ‘Garden Answers’.
Once you know how to identify common weeds, you can look at the soil conditions they prefer or tolerate and what they may indicate about your soil. Here are some examples of common weeds and what they may tell you about your soil:
Dandelion: This weed has a deep taproot that can break up compacted soil and bring up nutrients from deeper layers. It indicates poor drainage, low fertility, acidic pH, or hardpan.
Clover: This weed is a legume that can fix nitrogen from the air and enrich the soil. It indicates low nitrogen levels, acidic pH, or moist soil.
Chickweed: This weed is a succulent that thrives in moist and fertile soil. It indicates high nitrogen levels, neutral pH, or good drainage.
Plantain: This weed has broad leaves that can smother other plants. It indicates compacted soil, low calcium levels, acidic pH, or poor drainage.
Crabgrass: This weed is an annual grass that spreads quickly by seeds and runners. It indicates low fertility, alkaline pH, dry soil, or disturbed areas.
Thistle: This weed has spiny leaves and stems that deter herbivores. It indicates dry soil, low organic matter, alkaline pH, or poor drainage.
How to Improve Your Soil Based on Weed Indicators
Once you have identified the weeds that grow in your soil and what they indicate about your soil conditions, you can take steps to improve your soil health and fertility. Here are some general tips based on weed indicators:
If your soil is compacted or has hardpan (a dense layer of soil that prevents water and root penetration), you can aerate it by using a fork or a core aerator to loosen it up. You can also add organic matter such as compost or manure to improve the soil structure and drainage.
If your soil is acidic (below pH 7), you can raise the pH by adding lime or wood ash to make it more alkaline. You can also add organic matter such as compost or manure to buffer the pH and provide nutrients.
If your soil is alkaline (above pH 7), you can lower the pH by adding sulfur or peat moss to make it more acidic. You can also add organic matter such as compost or manure to buffer the pH and provide nutrients.
If your soil is low in fertility (lacking in nitrogen, phosphorus, potassium, calcium, magnesium, or other micronutrients), you can add organic matter such as compost or manure to enrich it. You can also use organic fertilizers such as blood meal, bone meal, fish emulsion, seaweed extract, or rock phosphate to supplement the soil nutrients.
If your soil is dry or sandy (lacking in water retention and organic matter), you can add organic matter such as compost or manure to improve the water holding capacity and soil structure. You can also mulch the soil surface with straw, leaves, wood chips, or grass clippings to conserve moisture and prevent evaporation.
If your soil is wet or clayey (lacking in drainage and aeration), you can add organic matter such as compost or manure to improve the soil structure and drainage. You can also add coarse materials such as sand, gravel, or perlite to increase the pore space and aeration. Peat moss or coconut coir helps to decompact clay as well if you mix it in.
Daikon Radish
Cover cropping with Daikon Radish to amend your soil can be another way to de-compact your clay-type soil and provide better aeration by adding organic matter once it decomposes. They provide deep tap roots that break through the most stubborn compacted soils. Just make sure not to step or walk through that area again lol.
Weeds are not just nuisances, they are also teachers. By identifying the weeds that grow in your soil and what they tell you about your soil conditions, you can learn how to improve your soil health and fertility for better gardening results. Ill be posting more about different weeds in another post. Remember, healthy soil means healthy plants!