When is compost ready?

QUESTION: When is compost ready? I have been adding kitchen scraps and some leaves to the large bin in my back yard for almost a year. How do I know when I’m done and can use it? – Erwin B

GARDENING CHANNEL REPLIES: Compost can be ready anywhere between month one of decomposing and month twelve. When it’s ready depends more upon its purpose than anything.

You should first consider what you’ll be using the compost for. If you’re planting with it, you may need the compost to be broken down into a finer product.

However, if it’s more of a mulch, you may be able to get away with it not being as decomposed.

The next thing you must consider is the size of the ingredients at the time of adding them to your compost pile.

Are the items which make up your compost larger or did you break them up prior to adding them to the pile? This will make a difference in how long it takes your compost to be ready for use.

There are a few signs you can look for when determining if your compost is ready. The first thing to look at is the size of your pile. When it has shrunken by approximately 50%, it’s probably ready for use.

The next thing to consider is the materials. Can you recognize the original ingredients that went into your compost pile? If so, the compost isn’t ready. If the ingredients are broken down and blended together, this could mean you’re ready to utilize your compost.

Next, is there heat coming from the pile? When compost is still producing heat, it means it’s still breaking down and therefore, isn’t ready for use.

You may also look at the texture and smell your compost. When it has an earthy smell and looks rich and textured and almost like soil, it’s probably ready.

The last method for testing your compost is to plant in it. It’s recommended to plant a handful of radish seeds in the compost as they have a quick germination time.

If 75% of the seeds germinate, your compost is ready. If not, wait a little while and try again.

What should you do if your compost has finished producing heat but still isn’t broken down enough for your taste? Let it sit.

You should add some moisture to the pile from time to time and turn it to aerate your compost. This is called the curing process.

Once the compost has cured, and meets your textural goals, you may use it. If you want confirmation that the compost is ready, use the seed test.

Compost is a wonderful way to add nutrients to your plants and for use as a growing medium. It’s also cost-effective when you create your own.

However, knowing when homemade compost is ready sometimes feels tricky. Hopefully, these tips have shed some light on how you can know when your DIY compost is ready for use.

Learn More About Compost

https://extension.missouri.edu/publications/g6956

https://extension.umn.edu/managing-soil-and-nutrients/composting-home-gardens

https://extension.psu.edu/home-composting-a-guide-for-home-gardeners