Can I Reuse Soil from a Dead Plant?


Quality soil is essential to growing beautiful, healthy plants. Soil contains the vital nutrients that allow all plants to thrive. So, if you are considering reusing soil from a dead plant, there are steps you should take to make sure the soil is suitable for new growth.

Can you reuse soil from a dead plant? Yes, you can reuse soil from a dead plant. However, the old plant has used up most of the beneficial nutrients in the soil, so they need to be replenished with compost or other soil enhancers before planting new seeds in it.

There are quite a few different options to make sure your old soil is revived before you plant something new. From tilling the soil and sanitizing it to composting and worms, there are many options out there for those willing to put in a few minutes of work for excellent quality soil. Read on to learn how to diagnose, treat, and replenish your soil through a few simple methods.

Diagnosing the Issue: Why Did the Plant Die?

Before we dive into how to reuse soil, make sure you know why your first plant died. This could have a significant effect on whether you can reuse the soil successfully or not.

Common causes of plant death include:

  • Lack of water
  • Freezing temperatures
  • Lack of sunshine
  • Insect infestation
  • Fungi
  • Bacteria
  • Nutrient deficiency
  • Overwatering

While there are many ways for a plant to die, it is crucial to identify which one may have killed the plant. If it was fungus, insects, or mold, the soil might be contaminated.

To figure out the plant’s cause of death, follow these steps:

  • Grab some gardening gloves and a trowel.
  • After removing the old plant, shake off excess dirt to keep it in the planter.
  • Next, inspect the plant and the soil around it.
  • Use the trowel to turn the soil over.
  • Look for any bug infestations, such as small eggs or larvae.
  • Look at the stem and leaves of the dead plant for discoloration or anything else out of the ordinary.

This inspection will alert you to potential contaminations. If you suspect your plant was the victim of a fungus or infection upon inspection, you will need to sanitize your used soil first before repotting a plant.

Reusing Old Soil: The First Steps

The first step to reusing old soil is to remove organic matter. This includes dead roots, leaves, or pieces of bark. It is a great thing to do while you are inspecting your soil and turning it with a trowel.

While sticks, leaves, and dead roots eventually break down in nature, they will not breakdown or provide any valuable nutrients in a potted plant. Instead, they take up valuable space where hearty soil and minerals that are more nutrient-dense could be. Feel free to toss the old leaves, roots, and other items outside so they can decompose naturally.

As you turn the soil over with your trowel and dispose of the organic matter, you will bring air into the soil, rejuvenating it. Also, this loosens the soil back up for new roots from a new plant to grow quickly.

Sanitizing Soil before Reuse

If you determined that your soil may have bacteria or bug infestations in it, it is essential to sanitize it thoroughly. If you are doing this during a hot summer, you can put your soil in a few dark containers and set it in the sun for a few days. The heat and sunshine will kill anything harmful in the soil.

However, gardeners are often unpotting plants once they have died in the fall and winter, and a different sanitation method is necessary.

To sanitize soil in the fall and winter, follow these steps:

  • Lay the soil out on a few roasting pans, three to four inches thick.
  • Spray it heavily with water, so it is damp but not muddy.
  • Cover the pans with another tray or aluminum foil, leaving a small space ventilation.
  • Then, place the pans in a 200-degree oven for two hours.
  • Remove the pans from the oven and let cool for a few hours.

This method allows the soil to reach a minimum of 150 degrees for at least 30 minutes, which sanitizes it efficiently.

In addition to sanitizing your soil, you may need to clean your pots if you suspect fungi or bacteria are growing on them. You can use any household sterilizer to wipe them down and kill bacteria if you follow the directions supplied with the cleaner. A common one is wiping them down with bleach water to kill any harmful bacteria. This is best done at the end of the planting season.

Replenishing the Nutrients in Your Soil

Next, you need to spruce up the old soil and give it a new life. If you compost or know someone who does, this is the perfect way to use it. Composting does take time, so only use it if it has turned to fertile, dark soil. If it still has remnants of food scraps in it, do not use it. It is not yet ready to give life to something else.

We recommend a 1:1 ratio of old soil to compost or other soil enhancers. This lets you reuse old soil without depriving a new plant of essential minerals. If you do not have compost available, there is plenty of potting soil rich in nutrients ready to get mixed in. Look for bags that provide extra nutrients, which often look like small white balls mixed in with the dark, rich soil.

While Miracle Grow is one common way to add nourishment back to the soil, consider all your options. There are fantastic plant food options that are specifically designed for vegetables or flowers.

Another more natural way to add nutrients back to the soil is through worm castings. Worms are the soil’s natural aerators and provide great plant food through their sheddings. Mixing some worm castings into the soil will give your new plants a great place to thrive.

Other things to pay attention to when picking a soil additive is what is best for your region and area. Your soil and water retention needs will differ based on sunlight, inside vs. outside, and what plant you are growing. Succulents, for instance, have specific soil that will help them become much better than a standard potting soil.

Choosing a New Plant for Old Soil

Plants all vary significantly in what they need to thrive. Broccoli, for instance, pulls different nutrients from the soil than daisies. Broccoli needs lots of calcium and magnesium, while flowers and root vegetables need lots of potassium. Because of this, you want to make sure you are rotating the plants you have in each container each year if you are able.

This will allow each plant to use different nutrients from the soil, without completely draining it of any specific mineral or nutrient. If you plant the same thing two years in a row in the same planter, the second-year crop will probably be quite underwhelming compared to your first year.

Reusing Old Soil

In nature, plants often grow their roots deeper and longer to seek out their necessary nutrients to live. However, in a pot, plants are limited in their resources they can pull from. So, having healthy and robust soil is mandatory if you want a plant to thrive. These few simple steps will help you reuse your old soil to grow a new, healthy plant.

Eyerly Family

The Eyerly Family is a family of 8 that loves gardening. Over the past several years we have been applying what we learn about gardening to our own 16x16 raised back yard garden. Our garden is very prolific and we grow a wide variety of vegetables which we love to eat! Click here to learn more about the Eyerly Family.

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