Does Potting Soil Go Bad? Can You Fix It?

Have you ever bought extra bags of potting soil that were left in the store for future use? Well, most people have done so, and they never thought the soil would go bad once they used the bags. 

But does potting soil go bad? In simple terms, YES! Potting soil comprises compost materials such as peat moss that start to compost over time. The time it takes before it begins to go bad depends on how you store it and whether it was opened or unopened. 

Potting soil is different from normal farm soil. That’s why it is important to find out if it can go bad, how to know it has gone bad, and the possible ways to rejuvenate it for future use. Read on to find out. 

Can your potting soil go bad?

When we talk about potting soil going bad, you have to understand that it’s just a matter of time before it goes bad. The only question you are supposed to ask is how long before it goes bad. 

The bag has an expiry date to show you when the potting soil goes bad. When the potting soil goes bad, it loses its aeration, drainage, and pH properties. Once this happens, the soil is unusable for growing plants.

You have to look at two scenarios: opened and unopened bags. 

How long does open bags of potting soil last?

Leaving bags of potting soil half full happens all the time, especially when you are adding extra soil to pots after planting. This extra soil has to remain in store until the next season when you’ll need it for planting. 

Since the soil has already been exposed to air, the fungi inside the soil will start to grow, causing the soil to degrade. 

When this happens, the open potting soil will have at most 6 months before it starts to go bad. It happens even if you place it in ideal room conditions. But, if you place it in humid conditions, it will degrade faster because the soil gets contaminated with fungal spores that build mold in the soil. 

How long does unopened bags of potting soil last?

For unopened bags, it’s a different case because the soil hasn’t been exposed to air. Also, the soil is sealed from humidity and fungus spores. 

If you place the bags in ideal conditions, that is, a well-ventilated and dry room, the potting soil will last for 2 to 3 years before it starts to go bad. Ensure the packaging remains intact and not damaged during the storage period. 

How long does potting soil last when in use?

Potting soil is like any other soil; it relies on nutrients and organic matter to stay relevant to your plants. Once these are replenished from the soil, it can no longer grow plants. 

Proper maintenance of the soil can increase its shelf life. You can incorporate new organic matter, such as garden worms, fallen leaves, and organic compost. 

So, does potting soil go bad when in use? After some time, yes! The soil can last for one to two years when a plant grows, depending on your variety. Also, some plants use more nutrients than others, reducing the soil’s shelf life. 

How to tell if potting soil is bad. 

If you suspect your potting soil is bad, here are signs you can spot to determine if it’s bad. 

It is dense and compacted.

Compact soil is a problem that can cause plants to stop growing. That’s because plants need oxygen, microorganisms, and water moving through the soil for plants to grow. But compact soil doesn’t allow this process to happen. 

The soil will become harder and denser if you continue adding water to the soil. You can test compact soil by pushing your finger without force into the topsoil. If it doesn’t happen effortlessly, then the soil is compact. 

How to fix compact soil

To fix compact soil, you need to break down the soil into small particles so that air and organisms can penetrate easily. To do so, poke the soil using a bamboo skewer or pour it out of the container and break it into small particles. 

Mix it with coconut coir or other ingredients that improve soil aeration to improve its structure and texture. You can also add rocks at the bottom of the pot to improve aeration and humidity. 

Soil has a bad smell. 

The soil will produce a rotten egg odor that results from the growth of bacteria in the soil. Bacteria start to grow when you overwater the soil, leaving standing water for longer periods. When the rotting smell happens, it means the roots are rotten. 

How to fix smelly potting soil

The best thing to do is to empty the soil from the pot and change it with fresh soil. Or you can place the soil in direct sunlight and let it dry to remove excess moisture. Then you can add some aeration and proper drainage to the dried soil. 

Add nutrients such as fertilizer, manure, or compost before using the soil. 

Poor plant growth

For a plant to grow in soil, it will require nutrients that are mixed in the soil. However, your plants will grow poorly if the soil doesn’t have these necessary nutrients. For instance, a plant will have stunted growth due to a lack of nutrients. 

How to fix poor plant growth

If this happens, you must add nutrients every few months to feed the soil. It can be a top dressing of nutrient-rich worm castings, compost, or artificial fertilizers for a quick boost. 

If the soil is beyond rejuvenation, pour it out of the container and add fresh soil. 

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Does potting soil go bad if it freezes?

No. Freezing potting soil can be a good way of sterilizing the soil. Hat’s because contaminants such as pathogens, fungus spores, and pests cannot survive in freezing temperatures for a few days. 

So, if you freeze potting soil, it won’t go bad. However, you must give it time to thaw before you mix it with organic materials. 

Is it okay to use old potting soil?

You could use old potting soil if the previous plant were healthy. You can also rejuvenate it by adding drainage, aeration, and texture to the soil. Also, add fertilizer or compost to feed the soil with nutrients. 

How can you rejuvenate old potting soil?

To revive old soil, you must add additives to improve its structure, aeration, and nutrients. The additives include; coconut coir, pet moss, sand, bark chips, perlite, and vermiculite. 

Then add slow-release fertilizer granules or organic fertilizer like worm castings and mix it with the old potting soil. Worm castings have a high concentration of organic matter that can mix easily with old soil. 

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