Can You Trim Roots In Hydroponics? (Detailed Guide)

If you grow plants through hydroponics for any length of time, you’ll come across issues with roots getting large and knotted with certain plants. 

Or even worse, you’ll have to deal with root rot. 

Trimming and pruning roots in hydroponics is a valid option I’d heard about, so I researched and asked around to fellow gardeners, and here’s what I found. 

Keep your plants healthy and growing quickly by trimming roots in hydroponics. Use sterile pruning shears to keep the cuts clean. Remove the plant pot from the system, trim any brown or discolored roots, avoid the root crown, trim only the bottom third of the roots, and replace the plant pot. 

Look ahead for more details on how this simple task can make a huge difference in keeping your hydroponic plants growing fast. 

Can You Trim Roots In Hydroponics? 6 Simple Steps

Trimming roots may seem extra, but it’ll help these plants stay healthy and grow faster in a hydroponic system. 

And since hydroponic plants already grow faster, this is pretty impressive! 

It’s easy to do once you know how, so check out these 6 steps and get started. 

Check The Root Growth

Check on your plants’ roots daily, and if this isn’t possible, make sure you inspect them at least every 3 days. 

Hydroponic plants don’t need extensive root systems to compete with soil and draw nutrients farther away from the plant. 

Everything’s in the water, and it’s all delivered right to the roots.

Hydroponic plants don’t need tough and thick roots; they spend all their energy growing the plant itself, which is why they grow so fast compared to soil plants. 

The downside is that if the roots start to have problems, it’ll affect the plant quickly. 

Look for these signs and if you see them, get ready to trim: 

• Tangled root mass
• Off-shoots of the roots where a few are much longer than the rest
• Discolored or dying roots
• Signs of mold, algae, or fungi
• Any roots getting into your water delivery systems

Keep The Right Pruning Tools

Once you’ve decided to trim roots for hydroponics, you need to make sure you have the right tools. 

I’ll be honest: I didn’t always do this. 

Once, I tried to use regular scissors because I couldn’t find my little pruning shears. 

My wife (the real gardener) freaked out on me! It turns out I passed bacteria onto the plant’s roots AND mangled the fibers of the root. 

The plant ended up dying. 

Quickly. 

Keep your tools sanitized. You defeat the purpose of trimming infected roots if you then infect other roots more with unclean tools. 

Washing with dish soap and warm water does the job well with little time. 

Ensure you rinse well to keep soap off the roots and then dry the trimmers well to prevent rust later on. 

Also, stick with real gardening tools. They’re designed to give a clean cut, and the plant recovers quickly from cuts such as this. 

I prefer these microtip pruning shears because they’re small enough for lettuce and herbs, but also strong enough for medium-sized plant roots. 

Trim Target Roots

Remove the plant pot gently to see the roots. 

Look for signs of mold or algae in the root system and wipe it off gently. 

Head to your target roots (infected, tangle, long, or impacting the water system) and visualize your cuts.

Healthy roots are smooth to the touch and look white. 

Browning roots or other discoloration indicates a buildup of bacteria, so these are good places to trim. 

If you’re unsure if it’s an infection or a concentration of nutrition, give the roots a gentle touch. 

Infection feels slimy rather than smooth. 

If you see any dry or shriveled roots compared to the size of the others, these are dead or dying. 

Trim these to help the plant redistribute its energy into growing in the healthy parts of the plant. 

You don’t want to take too much of the roots, so save as much of the roots as possible.

Never trim more than 10% of the root mass at any one time.  

Start trimming, giving as much of a clean cut at a 45-degree angle as possible. 

Don’t cut like crazy though, keep these next two steps in mind. 

Avoid Root Crown

The root crown is the part of the plant where the roots meet the plant body.

Many gardeners consider this the heart of the plant. 

Prune this, and you’ll kill it. 

The crown is the part where all the roots start coming together. 

It almost looks like a root-y crown. 

Prune Bottom Third Only

The roots closer to the plant body are stronger than the bottom of the roots. 

The ones at the top have more receptors for nutrients and oxygen, especially if you’re using mason jar hydroponics, which uses an air gap at the top of the roots to oxygenate the plant. 

Check out our guide for making your own homemade mason jar hydroponics. 

A good rule of thumb is to only trim the bottom third of the roots only. 

The exception to this rule is if the root is dead, though you should still keep your distance from the root crown, even in this instance. 

Put The Plant Back

Once this is all done, it’s time to put the plant back. 

Putting it back is tougher than pulling it out. 

You want to avoid showing the roots through the hole. Use your fingers to gently guide the roots together as you put them back into place. 

Make sure you avoid getting anything into the container as this could bring bacteria to your warm, nutrient-rich water solution. 

Then you’ll have more infections and start the hydroponic root pruning process all over again.

What Is Root Pruning?

Root pruning is when you trim a small portion of the root to encourage healthy growth and remove the chance of spreading infection. 

It works much like pruning or trimming on the tops or foliage of your plants.

As we talked about before, all root trimmings need to keep this in mind: 

• Use clean, garden-specific tools. 
• Avoid the root crown.
• Never trim more than 10% of the root mass. 
• Prune the bottom third of the roots only (where possible). 
• Don’t get debris on the roots. 

Why Should You Prune Roots?

Pruning roots in hydroponics helps out a lot, but it isn’t something you need to do with all of your plants. 

If they have a short growth cycle to harvest, you’ll likely never need to trim it at all. 

Root-bound plants are the biggest issue you’ll see. This is when the roots have filled the entire container. 

When the roots start to spiral, they won’t be able to pull in as many nutrients as before, and the growth will slow or stop. 

In a hydroponic system, roots grow explosively, so be sure to check daily on the roots. A good sign you need to look a little closer is when the top of the plant grows quickly in a short period.

Here’s a quick list of the reasons trimming roots in hydroponics is a big help: 

• Prevents root binding
• Ensures better nutrient and moisture uptake
• Stops roots from clogging drains and pumps
• Encourage the roots to spread out as well as down
• Removes dead or infected tissue