Good quality potting soil isn’t cheap and if your home is filled with houseplants or if you like to populate your outdoor space with flower-filled containers, potting soil can be a considerable investment. If this sounds familiar, you’ll be glad to learn that you don’t necessarily need to replace potting soil every year. How do you know when new potting soil is necessary? Here are factors to consider.
When New Soil in Containers is Necessary
When is it time to completely replace potting soil? Sometimes simply refreshing potting mix isn’t enough and you need to replace old potting mix with fresh mix. Consider the following:
- Are your plants healthy? If your plants haven’t been thriving or if the potting soil is compacted and no longer retains moisture, the mix is probably depleted and should be replaced. Healthy potting mix should be loose and fluffy. Start over with fresh mix if you’ve lost plants to root rot or other plant diseases, or if the plants have been infested by slugs or other pests.
- What are you growing? Some plants such as tomatoes, peppers, and cucumbers are heavy feeders that do best with fresh potting soil every year. Also, it’s a good idea to replace potting mix entirely if you’re making a switch from edibles to flowers, or vice-versa.
How to Refresh Potted Plants
If your plants are doing well and your potting mix looks good, there’s no real reason for changing potting soil completely. Instead, refresh potted plants by replacing a portion of the existing potting mix with a combination of fresh, healthy materials.
Remove about a third of the existing potting mix, along with any clumps or remaining plant roots. Sprinkle a few handfuls of perlite over the old potting mix. Perlite is a key ingredient that allows air to move freely through the container. Add a healthy layer of fresh compost.
Sprinkle a little slow-release fertilizer over the mix. Slow-release fertilizer provides consistent nutrients over a period of time. Top off the container with fresh, high-quality potting mix. Mix the fresh materials into the old potting mix with a trowel.
Avoiding Waste After You Replace Potting Soil
Your old potting mix doesn’t have to go to waste. Spread it over the soil in your flower beds or vegetable garden, then work it in lightly with a spade or rake. The old stuff won’t hurt a thing, and it may improve the quality of the soil.
The exception is if the potting soil is infested with pests or the plants in the pot were diseased. Put the potting mix in a plastic bag and discard it in a waste receptacle.
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FAQs
If your plants are doing well and your potting mix looks good, there's no real reason for changing potting soil completely. Instead, refresh potted plants by replacing a portion of the existing potting mix with a combination of fresh, healthy materials.
Should I replace the soil in my potted plants? ›
Plants typically benefit from being repotted every 12 to 18 months, depending on how actively they are growing. Some slow growers, like cacti, can call the same pot home for years, but will just require a soil replenishment.
How do you make old potting soil good again? ›
As old soil might be deficient in plant nutrients, you need to replenish it. Here are some ways you can add nutrients and organic matter to soil: Add a handful of a slow release fertilizer like manure. Mix in one part compost for every three or four parts of the old potting mix.
How often should you replace potting soil? ›
In general, it's recommended to replace potting soil every two to three years. However, if you notice a decline in plant health or growth, refreshing the soil more frequently may be necessary. When you do decide it's time, make sure to replace your soil before the growing season.
Can I put new soil on top of old soil? ›
Top It Off
Ideally, the soil comes to within an inch or so of the rim of the planter or raised bed. Use a fork or hand tool to blend the new soil into the old soil. Blend new soil into the old soil.
Does potting soil go bad in pots? ›
Does potting soil go bad? The quick answer is yes. Old potting soil loses value over time as its ingredients, like peat moss, decompose. But don't worry, you can easily revive your old potting soil back to health.
How do you rejuvenate potted plants? ›
Using an all-purpose slow-release fertilizer should do the trick for most houseplants. Mark your calendar when you fertilize and follow-up as per each plant's recommendation. Fertilizing your plants is a great way to revive them and give them the essential nutrients they need to thrive.
How do you perk up potted plants? ›
“If a plant has been severely underwatered, a quick way to revive it is to let it soak in water for a few hours,” says Vickie Christensen, master gardener and plant doctor at Léon & George. “Many plants go from droopy and sad to beautiful, lush and perky in just one day with this method!”
How to 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.
Is 2 year old potting soil still good? ›
Yes, you can use potting soil that is two years old. However, the nutrients in the soil may have depleted over time, especially if the soil has been used before.
It's generally fine to reuse high-quality potting soil if whatever you were growing in it was healthy.
Can you use the same potting soil two years in a row? ›
Potting soil that looks and smells fine after two years may retain some benefits. But rather than risk it in containers, consider beefing up ordinary garden soil by mixing it into raised beds or in-ground plots. Used potting soil can also add desirable volume and organic matter to a compost pile.
How to change soil in a potted plant? ›
How to Repot Your Plants, Step by Step
- Remove the plant from its old planter. You have to be gentle during this process. ...
- Loosen the plant's roots. ...
- Get rid of old potting mix. ...
- Add new potting mix. ...
- Add your plant.
Soil can become depleted and hard over time, holding less water and nutrients. But how often you change soil in potted plants depends on the plant. Faster growing houseplants may need annual repotting, while slower growers may be able to wait 1.5 to 2 years.
Do I need to replace soil in container garden? ›
It is recommended that potting soil be replaced after each growing season. This is because the organic material in soil breaks down over time, leaving it vulnerable to pests and diseases. Additionally, soil loses nutrients over time, which can cause deficiencies in plants if not replaced.
Can you reuse soil from potted plants? ›
If plants died from bacterial, fungal or viral disease, then you definitely do not want to reuse the soil, as soilborne pathogens can still be present and active. However, if the plants that grew in the soil before were healthy, it is generally OK to reuse the potting soil.
Can you reuse soil that has root rot? ›
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.
How often do you change the soil in a planter box? ›
Most garden soils in outdoor planters should be replaced every 2-3 years. Over time, nutrients get depleted and the soil can become compacted. Replenishing with new soil gives plants fresh nutrients to thrive. For annual plants, we would recommend replacing the soil each year.
