Can You Still Use Soil With Old Roots in It?


If you’ve started digging in your garden again and preparing for your new crop this Spring, you may have been surprised to find a plethora of old, lifeless roots within your soil. These roots can be thin, stringy, yet still firm. Brushing through them and removing them can be a difficult task, so you may be wondering if it’s worth it.

You can still use soil with old roots in it, though you may consider taking them out if you’ve noticed your plants seem nutrient deficient. There are tons of benefits to using old soil, but there are also some downfalls, greedy roots being one of them. 

Yes, you can use soil with old roots in it. But should you? Below, we tackle the pros and cons of keeping old roots in your soil and give some tips on getting the most out of your old soil. 

Can You Reuse Soil With Dead Roots?

You can reuse soil with dead roots in it. You can still grow a practical garden with old roots, but removing them also has its benefits. You’ll likely want to remove the bigger roots that may be sucking up nutrients.

Whether you should reuse soil with dead roots will depend on your unique circumstance. Every gardener is different and has a different picture of what their garden should look like. For this reason, there’s no simple “yes” or “no” answer to this question.

Gardens’ Individual Needs Vary

The question about whether you can reuse soil with dead roots has sparked debate amongst gardening blogs, and even experts won’t tell you one way or another. Gardens are as unique as the people that grow them–the composition of the soil, types of plants you’re growing, microorganisms living within the dirt, and even your climate can have a significant effect on how you should be gardening. 

That’s why gardening, though there are books and classes and almanacs on best practices, will always come down to what works best for your garden.

We can guide your best garden by presenting you with all the information–good, bad, and ugly–about keeping old roots in your garden. 

Pros of Leaving Old Roots in Soil 

Some gardeners swear by leaving old roots in their soil. It makes sense that this would be a go-to methodology for natural gardeners. In nature, nobody takes the old plant roots out of the ground, and plants still grow accordingly. Those who believe in keeping old roots believe in it, and they might give you any of the following explanations. 

Dead Roots Feed Microorganisms 

In a basic sense, dead roots may be feeding the microorganisms that’ll eventually feed your thriving plants. By this logic, dead roots are helpful to growing your plants.

This principle makes sense because of the nutrient cycling process. In the life cycle of plants, all dead and decomposed organisms are a bonus for soil, in a sense. Soil feeds off discarded leaves, flowers, fruits, and other organic materials that fall to the surface. This concept explains why mulches and decomposing practices are so prevalent in gardening. Such additions create another layer of microorganisms that can then feed your plant. 

This video helps to explain the nutrient cycle a little more thoroughly:

Put simply, any dead plant material will be decomposed by microorganisms in our soil, and then the nutrients from this process will feed our plants. Dead roots, in essence, are another decomposable organic material that will give our plants nutrients. In this sense, your dead roots may be a help to your garden.

Still, there are other ways to get nutrients to your plants. 

  • Mulches and compost are helpful, in addition to worm farming. 
  • Nutrient-rich soil bags from organic supplies will also help you get more microorganisms within your soil. 

While the dead roots may help, they shouldn’t be your only method of feeding your plants.

Some of Your Plants May Not Be Dead After All

This is a pro and a con, depending on how thoroughly you plan your gardening each Spring. You may find that more plants than you thought are still living by not picking out the “dead” roots. Roots that may have appeared to be dead may sprout up as new life in your garden, which could be a plus if you liked what you grew last season. 

Dead Roots Can Function As Compost

As mentioned above, dead roots can be used as compost for your plants and other soil. However, you need to be sure these roots are fully dead. Living roots can make a comeback by absorbing the nutrients meant to go to your new crop, which can be detrimental to your garden. We’ll talk about this circumstance more below. 

Cons of Leaving Old Roots in Soil 

Many gardeners will discourage you from using old roots in your soil, for good reason. Old roots may be hogging nutrients from your new roots, can spring up if they aren’t actually dead right in the middle of your gardening plan, and can take up room where nutrient-rich soil or new roots should go. Below, we detail each of these caveats to old roots in your soil.

Old Roots May Be Hogging Nutrients 

Sometimes roots can look dead…but they’re not actually dead. One of the pros of dead roots is that these roots will decompose and feed your plant. If they haven’t wholly decomposed or even begun the decomposing process, these roots could be taking nutrients away from your new, growing plants. When this happens, the old roots drain the soil’s nutrients and make it harder for your plant to grow. 

Leaving Old Roots May Change Your Garden Plans

Again, this is a pro for some and a con for others, but leaving old roots may throw a wrench in your gardening plans. If you had planted tomatoes in your old cucumber patch or put perennials in your old annual garden, you may notice plants from the past coming back to haunt you. This would be incredibly frustrating if you were planning a rainbow garden, salsa garden, or any other garden bed with a specific layout.

Old Roots Take Up Room in Your Soil

It can be challenging for your new plants to grow roots if they get tangled up in old root systems. Old roots take up room in your soil that could be dedicated to nutrient-rich, plant-growing soil. Getting tangled up or navigating might make it harder for your new roots to settle themselves in the ground and dig deeper. 

The Bottom Line on Old Roots 

Old roots won’t make your soil barren or ruin your garden. You can still use the soil you’ve been using all season long, as long as it’s free of pests, diseases, and other undesirables. Whether or not an old root is undesirable is totally up to your gardening preferences. As gardeners, we know how stringy and messy those roots can get, and it may simply not be worth it to you to dig them all out of your soil. 

Can You Reuse Soil?

Whether you take or leave the old roots in your soil, you might want to consider whether or not old soil is even for you in the first place. You could grab new bags of soil at the hardware store, dig up all your old soil, and wheel it off somewhere. You may be wondering: is that a process you need to partake in?

You can reuse old soil as long as you’re sure it’s pest and infection-free. Sometimes, soil can hold onto unwanted creatures rot from old infections. At the same time, using old soil can provide already nutrient-heavy and microorganism-rich soil to your new plants.

If you’re going to reuse soil, you can take steps to ensure it keeps your plants healthy and thriving. Some methods include removing tough-to-pull roots from old plants (if you decide you don’t want to leave old roots in your soil). 

How To Reuse Soil Effectively

Reusing your soil can be as easy as putting your plants directly into the garden bed. However, reusing soil could also require sterilization, reapplying compost, and getting rid of old roots. 

This video explains how you can rejuvenate your old soil:

Below, we discuss some additional strategies for soil rejuvenation:

Sterilize Your Soil

Sterilizing your soil may prepare it for a new batch of plants if you faced pest problems, infections, or diseases in your last crop. Sterilizing essentially means removing the soil of any microorganisms or organisms otherwise living within the system. Methods for sterilizing include the following:

  • Boiling water and pouring on small sections of your garden (away from any plants you want to keep living).
  • Steaming soil in batches.
  • Placing batches of soil in the oven, microwave, or freezer.

The caveat to sterilizing soil is that it kills every organism within the soil, good or bad. So, if you use old soil to help your plants indulge in ancestral microorganisms that the plants before use, sterilizing it will completely reset the microbiome. 

Check Your Garden for Light, Moisture, and pH

Using a moisture meter can help you see how much light, moisture, and acidity is already within your garden bed before planting. If you find that your garden bed isn’t getting a lot of light, and you don’t expect this to change with the seasons, you might consider choosing plants that need the least amount of light. If you find your soil’s pH is off, you can often adjust the pH with compost or fertilizer. 

Get Rid of Old Roots

Jeff Choate, an OSU Extension horticulturist, isn’t opposed to leaving old roots in the garden’s soil. He believes that as long as plants get the right amount of water and fertilizer, old roots decomposing in the soil shouldn’t significantly affect new growth. However, old root systems aren’t all about hogging nutrients. They can also make it difficult to grow new root systems. 

Choate suggests digging out the specific area in which you’ll add a new root system and removing the old roots from there. This way, you don’t have to cover the entire garden area, just where you want your new plants to grow.

Conclusion

Using old soil has its benefits, convenience being one of them. Whether or not you want to commit to removing old roots from your garden is totally up to your preferences. Before you make your decision, weigh out the pros and cons of root removal. If you do decide to go the no-root route, there are ways you can make this process a little simpler, giving you more time to plant your beautiful new crop.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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