Potting soil plays a central role in backyard gardening during the summer months. That’s when gardeners are installing new beds, refreshing old beds, and planting seeds and starts. Roll around to the end of August and the growing season is coming to an end, sometimes before the bags of potting soil are used up. And then there’s the potting soil used to grow annuals that have germinated, flowered, and died.
So, what to do with old potting soil? If you are wondering what to do with old soil, read on. We have a lot of good ideas for you.
Do You Throw Away Old Potting Soil?
The throw-away culture of yesteryear is now considered wasteful. Our nation has become more conscious of waste. As recycling came into its own, disposable straws disappeared from the coffee shops and one-use bags were banned from grocery stores. That new awareness means that tossing out old potting soil just isn’t an acceptable option.
Yet you have to do something with old potting soil. Do you find yourself asking “Where can I dump old potting soil?” Or, “Can I put old potting soil on my lawn?” You definitely can recycle that potting soil yourself in your very own garden.
What to Do With Old Potting Soil
Potting soil doesn’t “go bad” after one use. That means that you can treat unused half-bags of potting soil in exactly the same manner as potting soil that was to grow pots of annuals or vegetables during spring and/or summer. Just be sure not to reuse soil that was used to grow potted plants that died from bacterial, fungal or viral disease.
Assuming that isn’t the case, you have options! Here are six great ones to consider.
- Landscape hole filler or topper for current beds - Use old potting soil in the landscape to fill any holes on footpaths. It can also be used to top off existing flower and vegetable garden beds. The soil acts as a sort of mulch to protect the old beds from temperature swings. Don’t use soil from potted plants that died from disease, however, without sterilizing it.
- Starter soil for new beds - Are you installing new beds in your garden that will be used in spring for flowers or crops? Old potting soil makes a great base soil. In the spring, you will top it with new soil and add appropriate fertilizer.
- Compost heap - Here is the easiest option of all: Simply toss the old soil or unused half-bags of soil right on the compost bin. A good compost pile should be a balanced mix of green material, brown material and soil. As you blend in green and brown materials, the old potting soil will be incorporated into the compost to be used for future plantings.
- Layered on lawn - Lawns need love in winter too. Why not spread a thin layer of the old potting soil on top of that lawn. Over time it will work its way into the soil, and, in the meanwhile, it will offer some winter protection.
- Reuse in potted plants - Out with the old, in with the new! That attitude was typical for in years gone by when it came to old potting soil, but it isn’t the rule anymore. It is entirely possible to reuse soil recovered from container planting as long as you blend in about ⅓ new potting soil and add fertilizer for nutrients.
- Make a potato bin - What is a potato bin? It’s a home-made container made of box-wire frame and up to 4 feet (1.2 m) tall in which potatoes will be grown. Start this project in the fall by layering newspaper in the bottom of the bin, then add used potting soil, shredded fall leaves, aged horse manure and compost. Let this sit all winter long and toss in seed potatoes in spring.
Frequently Asked Questions
Do I Have to Replace Potting Soil Every Year?
When you use potting soil for container plantings, it’s not a good idea to leave the same soil in the pot for next year’s plants.
That is because the nutrients in the soil have mostly been depleted by that year’s growth. In addition, some used potting soil may contain pathogens.
Can I Put Old Potting Soil in My Garden?
Yes, you can use old potting soil in your garden beds.
It’s possible to use it to start new beds, layer it on the lawn, use it to top the soil in current beds, or even make a potato bin.
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FAQs
Add the used potting soil to your compost pile,” he said. “A good compost pile has a mixture of green material, brown material and soil. The finished compost can be used to fill garden containers later in the season. The used potting soil can also be added to garden beds.”
How to re-use old potting soil? ›
Add the used potting soil to your compost pile,” he said. “A good compost pile has a mixture of green material, brown material and soil. The finished compost can be used to fill garden containers later in the season. The used potting soil can also be added to garden beds.”
Can I put old potting soil on my lawn? ›
Many people simply throw the soil in the garbage, but it can be used in many other ways. First, the soil can simply be used to fill holes in the yard or top off landscape beds and other potted plants. The soil also can be spread thinly over the lawn or added to compost.
How many years is potting soil good for? ›
How Long Can You Store Potting Soil? Opened bags of new potting soil can retain quality for around 6 to 12 months. For unopened and unused potting soil, you can store it for about a year or two before it goes bad. Usually, potting soil lasts longer when stored in a dry and cool container.
How to tell if potting soil is bad? ›
If your potting soil starts to smell sour, foul, or rotten, it's a sign that the soil has likely gone anaerobic due to overwatering or poor drainage. Anaerobic conditions can be harmful to plant roots and hinder plant growth.
Can I bring old soil back to life? ›
Mix in one part of fresh organic matter like homemade compost, worm castings, or mushroom compost for every two parts of your veteran soil. It rejuvenates the soil, bringing back essential nutrients and structure.
How do you sterilize old potting soil? ›
Steaming: Steaming is considered one of the best ways to sterilize potting soil and should be done for at least 30 minutes or until the temperature reaches 180 degrees F (82 C). Steaming can be done with or without a pressure cooker.
Will grass grow in potting soil? ›
Can You Grow Grass in Potting Soil? The simple answer is no, outdoor grass will not grow in potting soil. Potting soil is best for planting indoor grasses or plants in pots or containers. Instead, you should use topsoil to grow grass in your lawn or other outdoor areas.
How many times can you use the same potting soil? ›
As long as used potting soil still looks fairly fluffy and doesn't emit a rotten odor, gardeners should be able to use it again with good results. However, if the plants formerly grown in the potting soil struggled with disease or insect problems, it's probably best to discard the mix and start fresh next season.
Will plants grow in old soil? ›
You do not necessarily have to throw away old potting soil. Instead, you can choose to reuse or refresh it, depending on its condition. If the potting soil has not been heavily contaminated with pests, diseases, or has a lack of nutrients, it can be revitalized and reused for planting.
Unhealthy soil doesn't have the moisture and nutrients needed to thrive, which makes it dry, crumbling, and cracked. When you pick up the dirt, it might crumble quickly in your hands or be difficult to break apart. Proper watering and irrigation will improve the soil's condition in these instances.
Can I put new soil on top of old soil? ›
As far as adding new soil on top, it would leave the roots of your plants in the old soil. The front of the bed looks as if it is at the max height. So you wouldn't have to lift them. Those could just have the soil amended to add nutrients by digging around them and adding a compost.
How do you rehydrate potting soil? ›
Set the pot in a shallow container of water, allowing the soil to absorb the water slowly. It may take an hour or more to thoroughly re-wet the soil. Be careful not to leave pots soaking in standing water for more than a couple of hours.
Can I use old dried out potting soil? ›
Worn out potting soil used over and over again doesn't have many nutrients left for growing plants. Moisten both used and new dried out potting soil by adding water. The soil may be resistant and the water may run off. If that's the case, put the soil into a watertight container such as bucket or tub.
How to prepare old soil for new plants? ›
Here are seven simple things you can do now to prep soil now for next season:
- Take a Test. ...
- Leave the Roots. ...
- Add Compost. ...
- Spread Some Manure. ...
- Sprinkle with Fertilizer. ...
- Pile on the Leaves. ...
- Plant Cover Crops.
Firstly re-using the soil can be a risk since it's probably riddled with harmful bacteria and pathogens. If you want to reuse the soil you need to sterilise it before you repot - this can be very risky and it isn't highly recommended unless you have a thorough method of sterilisation.
