How Garden Weeds Can Help You Create Healthy Soil

Garden weeds are the bane of a gardener’s existence. Nobody really likes going out to the garden to weed, unless they are looking for a garden chore where they can go on auto-pilot. But did you know that the weeds in your garden tell a story? It’s true — these pesky plants give you great information about what’s going on in your soil, giving you a great opportunity to customize your soil amending strategy.

Of course, you’ll need to be able to identify the weeds first (try taking examples into your favorite local garden center or make an appointment with a Master Gardener at your County Extension Office), but once you’ve done that, you can thank them for helping you to create healthier soil for your plants.

Types of Garden Weeds

Thistle & Dandelions

If you’ve got hard, compacted soil, you’ll likely find an abundance of these weeds. The deep taproots of these plants are able to break through hardened soils to access minerals deep below. Ways to address compacted soil include avoiding heavy foot traffic, aerating your lawn, keeping tilling to a minimum (no more than once a year, or better yet, never), and adding soil amendments to break the soil up.

Nutgrass, Dock, Bindweed, & Sheep Sorrel

These weeds are attracted to wet or poorly drained soils, so your plants can get bogged down and rot. Add soil amendments that have a strong sand base to allow water to drain more freely, or consider building raised beds that have deep, well-draining soil.

Sandburs, Clover, Mullein, Ox-eye & Daisies

Soil that is deficient in nitrogen attracts these weeds. Nitrogen is critical for healthy leaf growth, so these weeds are telling you that your soil is lacking nutrients. Look for soil amendments that contain alfalfa meal, blood meal, or fish emulsion to add nitrogen back in.

Purslane, Henbit, Pigweed, Chickweed, Lamb’s Quarter

Here’s the silver lining in the weed saga. If you have these weeds, your soil is typically well-balanced and healthy. Congratulations! Now, you still don’t want them there, so simply remove them and continue on with your soil amendment program, because it’s working.

Weeds as a Cover Crop

Throughout the growing season edible plants deplete the soil of nutrients as they grow and produce crops, it is important to replenish the soil with those nutrients after each growing season. Cover crops are plants that add nutrients back into the soil and are one way to replenish extracted nutrients. Instead of being harvested at the end of their growing season, cover crops can be turned back into the soil to decompose, adding additional organic matter and nutrients. Weeds are often known as ‘nature’s cover crop’ because they serve a similar purpose and even though our first instinct is to pull them, leaving your weeds can grant you a myriad of benefits.

Weeds Help to Break Up the Soil

Weeds have what is known as a taproot that can break up soil and reduce compaction. Many plants grow better in loose well-draining soil, reducing soil compaction between growing seasons can be a key element to vegetable gardening success.

Weeds Protect the Soil

In the winter, many gardeners cannot grow edible crops, and depending on where you are your garden may be subject to harsh conditions like wind, rain, and snow. One simple and easy way to protect your soil and help ensure it doesn’t erode or wash away is to allow your weeds to flourish. Grass weeds have thick root masses that will help hold the soil in place despite the elements. Weeds can also act as a mulch for your garden, protecting it all winter long.

Weeds Bring Nutrients to the Surface

Even though weeds use up some of the soil’s nutrients, if they are allowed to complete their life cycle those nutrients will make their way back into the soil. Weed roots absorb nutrients and bring them up towards the surface of the soil where they are more easily accessible to other plants. Some weeds also produce carbon which can help with water retention and further increase nutrient levels and organic matter in the soil. Once the weed dies, those nutrients continue to be released back into the soil as it decomposes.

Weeds Attract Beneficial Insects

Managing pests in the garden is always a challenge but one great way to keep them at bay is by planting crops that will attract beneficial insects that ward off destructive pests like, aphids, leaf miners, and cabbage worms. Weeds provide food and shelter to insects such as ladybugs, lacewings, and praying mantises, by allowing weeds to grow in and around your garden you can increase the good bug population.

Weeds Attract Beneficial Pollinators

A garden’s best friend is a pollinator, fruits, vegetables, and flowers all benefit from pollinators and though weeds are often seen as unsightly intruders they can help attract and keep pollinators in your outdoor spaces all year long. Not all but many weeds produce flowers that attract bees, butterflies, and wasps. The pollen produced by weed flowers can keep pollinators fed until your edible and flower gardens return in the spring. By keeping pollinators around, when it comes time to pollinate your fruits and vegetables they will be there to help.

Composting Weeds

Hot Composting Weeds

Compost is one of the best things you can use to amend your garden soil. It is nutrient-rich and packed full of organic matter that will continue to break down over time. Composting weeds is a great way to add more nutrients into your compost, but if done incorrectly can leave you with a compost pile full of weeds. To ensure that the roots and seeds are unable to grow or germinate once they reenter your garden utilize hot composting. Ideally, hot compost piles frequently reach an average internal temperature of 145 degrees Fahrenheit which is hot enough to kill the weeds completely.

Weed Tea

Weed tea, similar to compost or fertilizer tea, is created by fermenting weeds in a bucket of water and is a great way to utilize a plant that often goes to waste. Weed tea is a type of liquid fertilizer that can deliver nutrients to your garden quickly and effectively. You use any weed when brewing up a batch of weed tea.

How to Make Weed Tea:

1. Fill a plastic bucket 2/3 of the way with tightly packed weeds
2. Fill your bucket with water
3. Cover with mesh or other material that will allow airflow
4. Place in a warm location for 1 to 2 weeks.
5. Stir every couple of days
6. Strain your tea through a cheesecloth to remove any large chunks or seeds.
7. Dilute with water until it’s the color of black or herbal tea, about 1:10 ratio
8. Pour at the base of plants or use as a foliar spray and reap the benefits of this nutrient-rich fertilizer