Can You Compost Weeds - The Challenge Of Successfully Composting Them

Can You Compost Weeds? The Challenge Of Successfully Composting Them

Have you been warned of the risks of composting weeds and you don’t know if you can compost them? Weeding is a dreaded garden activity because it might be hard to get rid of these longlasting and resistant plants. Weeds are plants hard to pull, they give plenty of seeds and multiply everywhere. Sometimes weeds climb on other plants, and in some cases, they can even smother others to death by weight or in a parasitic relation. 

We find ourselves weeding through the garden every other day, but weeds keep popping up. We then find ourselves facing a new problem: what to do with the weeds we just pulled? Can you compost weeds?  

Can You Compost Weeds?

Weeds never die is a common saying, but what are weeds and why do they “never die”? 

Can You Compost Weeds

Many say weeds shouldn’t be thrown into the compost bin. Weeds have very resistant seeds, that can remain alive even above 65°C (or 149°F). Most composts get to only 45-50°C (°F), because of many factors, such as:

  • Small size, warm composts need to be at least 1m3 (27 ft³). 
  • Not enough green organic matter was mixed in, in relation to the brown organic matter added. You can fix this lack of Nitrogen in the mix by adding more of the greens or even add some urine (with a concentrated and readily available nitrogen). 
  • Not turning it over often enough. How often do you turn it over? Once a week or once a month?
  • The climate where you keep the compost is too dry, too wet, or too cold. This can set back the decomposing process in your compost 

Composting of Weeds, how to succeed?

In order to succeed in composting weeds, the best thing to do is to observe the most common weeds in the location and learn how they look like in different life stages. Weed out as soon as you spot a weed in your garden, the sooner the better. 

Once it flowers, the plant will start producing seeds very quickly, and decomposing the weeds in the compost may not be enough to inactivate the seeds. When you fertilize your soil with the uncomposted weed’s seeds, they will eventually find the conditions to germinate, making it a never-ending process of weeding. 

Compost usually warms up, but in order to break the weeds seeds cycle, we must guarantee the heat to persist (above 65°C/ 149°F) during at least fifteen days in a row. 

The Quick Guide To Composting Weeds Successfully

  • Make sure you build a big compost pile to ensure its proper warming process. The size of the compost container should be double the volume of the final compost you want to obtain. You may find very detailed instructions on how to build six different types of compost bins or containers and their optimum sizes in this article
  • Cut organic matter into small pieces when possible.
  • Add enough brown organic matter to balance recently trimmed weeds (green matter). One bucket of green organic matter and one bucket of brown organic matter -or a bit more- is a good volume relation (1:1).
  • Keep the moisture content between 40 to 60%. The compost mix should feel moist to the touch.
  • Add chopped up weeds that have not yet flowered.
  • Turn the compost over frequently (at least twice a month).
  • Most importantly: compost weeds before they get to flower

Why Are Weeds Good For The Garden? 

The weeds of your garden have functions in the ecosystems.

1. Weeds are plants designed by Nature to regenerate soils. They like to grow especially in borders, eroded or poor soils, and besides trails and roads. 

2. Weeds are very resilient plants that prepare the soils for other more nutrient demanding plants in ecological succession. 

3. When soil is left bare or is turned around during tilling, seeds of weeds germinate easily and start their life mission: to hold the soil and nurture it. 

4. Weeds tend to be highly medicinal, nutritious, or can be extremely toxic. 

5. Many weeds have superpowers to absorb high quantities of certain minerals from the soil. Some of them are even used to regenerate heavily polluted soils (from contaminants such as oil, gasoline, and heavy metals).

6. Many animals develop a special relation to these kinds of plants and seek them for specific therapeutic results, including us humans.

7. They have accompanied humans during the ages and have a history of being related to witches, wizards, healers, and shamans all around the world. 

Why Are Weeds Good For The Garden

If you have more tips, leave in the comments what has worked for you when you compost weeds from your garden.

Go often to the house of thy friend,  for weeds soon choke up the unused path.

– Scandinavian proverb