Potting soil is crucial for growing potted plants but it can get really expensive. So I did research on how often you need to change the soil. This will help save you time, money, and effort for your potted plants as well.
You should change soil in potted plants every 12 to 18 months. This depends on the condition of the soil and how actively you are growing plants. With some fast-growing plants you may need to change it in a year. For slow-growing plants you may need to change it in 18 months.
The potting soil will last you based on how fast the plants consume the nutrients from it. You need to understand when you can change the soil, what kind of soil to use, and how you should change the soil.
How often should I change soil in my potted plants?
You should check the condition of the potting soil every year. If you water the plants, and the water just runs through the soil, it means you need to change the soil.
If you’re growing plants in pots and the plants are leaves are turning yellow, that could be a sign to change the soil. The nutrients may have exhausted in the soil and the plants cannot get the required amount.
If you can see roots of the plants sticking out from the bottom of the pot, that’s a sign you need to change the soil. The plants might have gotten root-bound where they have outgrown the soil and the pot.
If you find the potting soil has become hard to the touch and is not absorbing the water well, it’s an indication that you need to change the soil.
You may also find that the potted plants have grown larger in size and are toppling over. This is an indication you need to repot the plants in fresh potting soil.
For fast-growing plants like pothos and African violets, these issues can occur after a year. But for slow-growing plants like cactus and sansevieria, you may only need to change the soil after 2-3 years.
The best time to change the soil in the pots is during spring. This is the time when the plants are focused on growing new roots and foliage. So changing the soil will cause less stress to them as they can adapt well during the growth phase.
What kind of soil to use?
The best soil to use for your potted plants is potting mix. This is a sterile soil that may contain a mixture of peat moss, perlite, and vermiculite. You can also add some compost and slow-release fertilizer to the mix.
The texture of this soil is lightweight that absorbs sufficient moisture but drains out the excess. It allows good moisture and air circulation so the roots can get the required nutrients from the soil.
Do not use garden soil for your potted plants. This soil might contain too much clay that will retain excess water and drown the roots. Your plants may suffer from root rot due to this.
Or it may contain too much sand that will drain out the water fast and the plant’s roots will not be able to absorb the required nutrients and moisture from the soil.
The garden soil may also contain harmful pests and diseases that lurk around in such soil. These will infest your potted plants and cause harm to them.
The garden soil might contain chemicals from the pesticides that may have been used on the lawn. These chemicals might be harmful to your potted plants and dangerous if you’re growing edibles in them.
How do you change the soil in a potted plant?
- The first step is to collect the required materials which include fresh or revitalized potting soil, a pot with sufficient size, some flat stones, a watering can, and the existing potted plant.
- Place some stones at the base of the new pot. This will help prevent the potting soil from flowing out of the drainage holes. Make sure the stones don’t block the drainage holes.
- Now place some of the fresh potting soil in the new pot so it comes to a height sufficient to place the existing plant.
- Take the plant out of the pot along with the root ball. If you have a plastic pot this is easy to do. You just need to tap the pot from all sides, till the plant slides out.
- If the plant is in a terracotta pot, you may need to tap it several times. Or you may even need to break the pot if the plant is stuck inside.
- Take a little bit of soil from the bottom of the roots to check if the roots are healthy or you may need to trim some of them. If the plant has become root-bound, you can untangle some of the roots and trim them.
- Place the root ball in the new pot so that the base of the plant is just a couple of inches below the rim of the pot.
- You can add potting soil to the sides of the plant till it becomes stable in the new pot. Then use the watering can to water the plant well.
How do you rejuvenate old potting soil?
After a few years, the plants will have extracted all the nutrients from the potting soil. And the texture would have become firm making it unsuitable for growing a plant.
But you can rejuvenate this old potting soil and make it suitable for using again to grow a plant.
- The first thing you need to ensure is there are no unwanted materials in the soil. Break the soil up and place it on a tarp.
- Take out the roots, leaves, parts of plants, and debris you may find in the soil. Water the soil well so it can regain it’s soft and airy texture. Let the soil dry out on the tarp.
- You need to solarize the soil so it kills the harmful pests and diseases that may be lurking in it. The best way to do this is to cook the soil in an oven.
- Spread the soil in a disposable tray so it forms a layer that is 4 inches thick. Cover the tray with aluminum foil and make a hole in the center of the foil.
- Preheat the oven to 200 degrees Fahrenheit and place the tray with the soil in it.
- Let the soil cook in the oven for at least 30 minutes to ensure it’s sterilized. The soil needs to be heated to a temperature higher than 140 degrees Fahrenheit to kill all the bacteria and viruses.
- If you don’t want to use an oven, you can do the same with a black plastic bag. Place the potting soil in the black plastic bag and tie it shut. Put the plastic bag in a translucent container and leave it in the hot sun for an entire day.
- Once the soil has cooked either in the oven or in the sun, you need to cool it down to room temperature.
- Now that the potting soil is sterilized, you need to improve the nutrients in the soil. The best way to do this is by adding an equal amount of compost.
- The compost will add rich, organic nutrients and microorganisms to the potting soil. You can also add an all-purpose fertilizer to the soil. Mix in one tablespoon slow-release fertilizer for every 1 gallon of the soil.
- You can use the potting soil immediately for your plants or you can store it away in a dry, air-tight container for later use. The stored potting soil can last you for around 6 months.