When Do You Need to Add Organic Matter to Your Soil?

Have you struggled for years to get anything to grow in your garden? If so, the problem may be the quality of your soil. Whether you’re trying to grow larger plants or just trying to get anything to grow at all, you should be adding organic matter to soil annually. Here’s what you need to know about when, specifically, you should be adding organic matter.

When You Should Be Adding Organic Matter to Soil

You should be adding organic matter to soil at least a month before you intend to plant anything for the season if you are adding raw, or unfinished, organic matter to your soil. Examples of raw organic matter include manure that hasn’t decomposed, and leaves.

Giving your raw matter at least 30 days to decompose ensures your plants won’t break down before your raw organic matter. Add finished organic matter right before you plant.

Why You Should Add Organic Matter to Your Soil

You should add organic matter to your soil to improve its health and quality. Although you can’t change the type of soil you have, you can make it more conducive to growing larger vegetables, flowering plants, and fruit trees by improving its quality by adding organic matter. The great thing about adding organic matter to your soil is it benefits your soil regardless of the type of soil you have.

For example, if you have clay soil, adding organic matter will loosen and aerate it. If you have sandy soil, it will be able to hold more water and nutrients if you add organic matter. Finally, even healthy soil can benefit from the addition of organic material. Organic material attracts microorganisms, worms, nutritious fungi, and other living things that are beneficial to your vegetables’ health.

Why You Need to Loosen and Aerate Clay Soil

If you have clay soil and you’re trying to grow produce, it is extremely important to add organic matter. You need to aerate your clay soil by adding organic matter to it because aerated clay becomes loamy and allows water, nutrients, and air into the soil. This leads to your vegetables getting more water and nutrients so they can grow larger and more nutritious, providing you with more nutrients.

You need to loosen clay soil because compact clay soil leads to poor water drainage. While it is important for your plants to get water, you don’t want flooding to occur when it rains too hard. Loose soil, whether it is loamy soil that has been used for years or clay that you added a couple of inches of organic matter to, it will be great for your garden, your vegetables, and you.

What Kind of Organic Matter You Should Add to Your Soil?

Compost is the best organic matter to add to your soil. Compost is great because it is easy to use, readily available, and usually clean. You can buy bags of compost or have truckloads delivered if you’re adding organic matter to an acre of farmland. If you’re just trying to add organic matter to your vegetable garden, you can make your own compost by leaving eggshells, newspapers, vegetable scraps, and fruit peels in a pile.

After a year, your pile will turn into humus, a crumbly substance that resembles soil. Letting your scraps turn into humus naturally is known as cold composting. You can also try the technique known as hot composting; hot composting allows you to get results in three to four months rather than 12 months. To hot compost, mix carbon- and nitrogen-rich ingredients in a ratio of 25:1. Chop your raw material up as finely as possible and leave it in a large bin.

Pro Tip

Do your due diligence if you’re buying compost rather than making it yourself. Ask the company you want to buy from if the compost contains lead or any other heavy metals. If it does, keep calling compost sellers. You want the compost you buy to be free from heavy metals if possible. If you can’t find anyone selling compost without any heavy metals, make sure that the compost being sold is safe for vegetable gardens.

Other Kinds of Organic Matter You Can Add to Your Soil

Although compost is the best organic matter to add to your soil, there are other options. The two most notable alternatives to compost are sawdust and livestock manure. Each has its own advantages and disadvantages that only you can weigh against the convenience and affordability of compost.


You can add sawdust to your soil instead of compost. Over time, the sawdust decomposes and turns into humus, the crumbly material that compost is. However, you must consider very carefully whether adding sawdust to your soil is right for you. As sawdust decomposes, slowly turning into the same humus you could have purchased, it lowers the nitrogen levels in your soil.

There are several ways you can test the nitrogen levels in your soil. For instance, you can collect soil samples and send them off to a soil nitrate testing lab to be tested. However, the easiest way to tell if there is enough nitrogen in your soil during the growing season is to look for these symptoms of nitrogen deficiency in your plants:

  • Yellow or pale green leaves
  • Lower-than-expected crop yield
  • Stunted growth of vegetables

Livestock Manure

You can also add livestock manure to your soil instead of compost. The advantage of adding livestock manure is that it increases the levels of nitrogen in your soil so you don’t have to add as much fertilizer. However, you must be very careful if you want to use horse manure. Horse manure, as well as the manure of other livestock that sleep on dried hay or similar bedding, may contain things like dried hay that rob the soil of nitrogen.

How to Add Organic Matter to Your Soil

To add organic matter to your soil, start by deciding where you are going to plant your vegetables. Once you know where you’re going to plant your vegetables, add a layer of an inch or two of organic matter to that spot. You should put a 2″ layer down in you have a new garden or your soil is extremely sandy or made up of heavy clay. You can get away with only an inch of organic matter if you’ve been planting in the same spot for years.

For reference, you need a cubic yard of compost to spread a 1″ layer over 334 square feet. Once you’ve put your organic matter down, work it six inches into the ground. It is strongly advisable to use a shovel to get the manure or other organic matter six inches beneath the ground. You don’t want to dig holes with a spade and pack the matter into the holes by hand. Even if you’re wearing gardening gloves, using a shovel will save you time and be more sanitary.

Adding organic matter to soil is the key to improving garden soil that is less than perfect. It should be done a month before you intend to plant if you’re adding raw organic matter. If you’re adding finished organic matter, you can add it right before planting your seeds. Contact us at Amaral Farm to learn more.

Posted by Amaral Farms

HI and thanks for visiting my blog. I guess I would say I have always been a gardener at heart. My parents gardened and I helped them from a young age. As an adult I took to the organic movement and began gardening using almost exclusively organic methods. My focus has shifted the last decade to add heirloom gardening to the mix. By no means an expert, I do enjoy it and spend at least a few hours a week dedicated to it. I hope you enjoy and gain some value from my blog. Check out my tips for growing tomatoes in pots.