Store-bought compost is handy for when you have a large garden, or you’ve just started composting and have a few weeks or months of waiting before you can use your own. While compost doesn’t necessarily go bad in the way other organic matter does, it still needs to be stored properly for it to remain effective.
Here are a few tips to properly store shop-bought compost:
- Keep the compost in contact with the ground.
- Make sure your compost stays covered.
- Check the moisture levels regularly.
- Aerate your compost.
- Use breathable bags or bins with ventilation.
- Keep a tray underneath.
- Match the shelter to the weather.
In this article, I’ll explain these tips in more detail, explain what happens when compost is stored improperly, and how long your shop-bought compost will last, so read on!
1. Keep the Compost in Contact With the Ground
Compost of all kinds, whether store-bought or homemade, does well when it’s in contact with the ground. Ground contact introduces bacteria and other organisms like fungi and worms into your pile, which helps the compost stay alive and mature further as you store it.
Even when you’re composting at home, if you have the space, keeping your compost in contact with the ground is a good idea whether you’re composting with or without a bin.
Make sure that you place your compost a little way away from any water sources, as you don’t want any water leaching the nutrients from your compost onto the ground. You also want to be sure that any additional fertilizer in your shop-bought compost doesn’t burn your plants, so keep the compost pile a little away from your garden bed.
2. Make Sure Your Compost Stays Covered
If you’re piling your shop-bought compost outside, using a cover like a tarp is a good idea to keep the moisture in and excess water out.
It’s important that you don’t cover the pile to the point that it’s airtight because that’ll cause all the beneficial bacteria to die off. All the aerobic bacteria that help with the composting process need oxygen to survive.
Keeping your compost covered is also a good idea for windy spaces to ensure that your compost doesn’t blow over.
3. Check the Moisture Levels Regularly
Completed compost can stand to be a little drier than a working compost pile that needs to be watered regularly.
In partially decomposed compost, the lignin and cellulose compounds are still being broken down by bacteria. So they need the additional moisture to speed up their decomposition activities. Compounds like lignin are plant-based organic matter that needs extra moisture to break down.
However, completed compost doesn’t need to decompose organic material any further. It still needs to be kept moist to ensure that the helpful bacteria survive and continue to benefit the soil, but the compost doesn’t need to be as damp as a wrung-out sponge.
A good rule of thumb is to keep moisture levels on the lower end of the recommended 40 – 60 percent. Ensure that the texture of the compost is fluffy and crumbly as opposed to dusty and powdery, and your compost will be fine.
4. Aerate Your Compost
Air is vital to your compost, more so after the organic matter has finished decomposing. Air ensures that the compost matures well and prevents anaerobic decomposition from setting in.
When you’re storing your store-bought compost, you want to ensure that the compost doesn’t get compacted or too wet to maintain the health of the compost and keep it usable. The best way to help your shop-bought compost stay healthy is to turn and aerate it, especially if you have to store it for a long time.
You won’t need to turn the compost as often as you would when it’s heating up in the first two stages of composting. You can check on it every week or once every two weeks and turn it in then.
5. Use Breathable Bags or Bins With Ventilation
Suppose you don’t have the space to store your compost in breathable bags or bins. You can use cloth grocery bags, metal or plastic bins, or garbage cans with a lid. If you must use plastic to store your shop-bought compost, use hard, good-quality plastics.
Hard plastic containers are sturdy, cheap, and convenient and won’t leach toxins into your compost like thinner plastics like garbage bags. Garbage bags are likely to break down with microbial activity into microplastics that can later affect the health of your plants. Avoid using these bags unless you only need to store your shop-bought compost for a day or so.
Hard plastic or metal bins are great to use for storing and composting at home. You can leave the lid off smaller bins to aerate the compost, or drill ventilation holes into your bins with a soldering iron.
6. Keep a Tray Underneath
An important thing to remember is that compost, even completed compost, can release leachate that’ll stain whatever flooring that your bin or pile is on.
For the safety of your flooring, avoid placing the storage bin on wood or concrete flooring.
If you really don’t have a choice about where you put your storage bin, you can avoid staining issues by placing a tray underneath your bin.
Adding a tray under your compost storage bin is also a good idea for when you’re storing the compost outside. In case your bin gets rained on, you can collect the compost tea and use it instead of the leachate polluting any nearby water sources.
7. Match the Shelter to the Weather
Compost at any stage should be placed in a sheltered location and in a shaded area to prevent it from drying out too quickly. The shelter will also prevent your compost bin from being blown over and protect it from getting waterlogged in case it starts raining.
In the winter, there are greater chances of your compost getting too wet, which will kill the aerobic bacteria. If you’re storing your remaining compost to use in the spring, you should bring it indoors into a well-ventilated barn or basement to keep it warm, not too wet, and healthy.
Problems With Improperly Stored Compost
Improperly stored compost can cause a few problems for your plants and for your own health. Here are two of the main issues with improperly stored compost.
It Loses Nutrition As the Nitrogen Degrades
All the nutrition in compost is susceptible to degradation over time, but the released nitrogen is usually the first affected. A lot of nitrogen is lost during the composting process, and if stored improperly, the compost can heat up again, resulting in further nitrogen loss.
Keeping your shop-bought compost moist and aerating it regularly is important to maintaining its nutrition for as long as possible. It’s also just as important to protect your compost from rain or water that could run through and drain it of nutrients.
It Can Make You Sick
Mushrooms and other fungi are useful for breaking down complex plant compounds. They’re usually present as a white powder on top of your compost and responsible for breaking down woodier matter like twigs and sticks.
As these fungi usually emerge in the last cooling and maturation phase of composting, it’s very likely that your shop-bought compost will still have spores in them.
If you store your compost improperly and additional moisture gets into the bin or the bag, these spores can multiply and spread across the pile. While they aren’t necessarily harmful to the compost, they can make you sick if you accidentally inhale them.
Turning and aerating your compost, protecting it from rain and additional water, and wearing protective gear when working with it’ll keep you safe from falling sick.
How Long Does an Unopened Bag of Compost Last?
Healthy compost can last a long time. Natural compost frequently lasts forever, as naturally decomposed organic materials don’t have an expiry date.
Unopened bags of compost are effective for up to a year or a few years. Compost with Controlled Release Fertilizers will last about a year, after which the fertilizers might burn your plants. Completely organic fertilizer will last longer but will become less effective after a few years.
As I mentioned earlier, the nutrition in compost, like nitrogen and carbon, does dissipate with time, with the nitrogen breaking down first. However, compost can’t go bad or cause any problems with your plants if it’s old. It’ll simply be less effective. The only way compost can go bad is if it’s stored improperly.
Shop-bought compost needs to be stored in a sheltered space that protects it from the elements. Keeping it in contact with the ground is beneficial to keep it active and alive.
If you don’t have the space, you can always store the compost in bins with ventilation or breathable bags. Adding a tray to the bottom will prevent any stains and allow you to collect leachate that you can use as liquid fertilizer.