The Dangers of Overwatering and Overfertilizing Your Plants

By Kyle Ladenburger
Published: December 1, 2015 | Last updated: April 21, 2021 04:26:38
Key Takeaways

Have you ever been told by your doctor to slow down and take it easy? It’s common advice that should also be carried over into the plant world. In fact, The Plant Doctor, a.k.a. Kyle Ladenburger, wants everyone to stop overdoing it in their gardens. This means applying less water and less fertilizer to your plants. Follow his proven methods for plant success and you’ll soon see your struggling plants come back to life before your eyes.

Over the years I have earned recognition amongst family and friends for being a plant doctor. When their plants, particularly houseplants, experience trying times and suffer from some type of ailment or attack by pests, I put them into my personal care and bring them back to good health. I have an excellent track record and have brought numerous plants back from the brink of loss. Once the “patient” is in my care I carefully diagnose the problem at its cause, perform the needed procedures and begin the process of rehabilitation. More often than not, especially when it comes to typical houseplants, the plants are subject to one of two different problems: overwatering or overfertilizing.


The Danger of Overwatering Your Plants

The most common issue that lands a plant within the confines of my plant hospital is overwatering. Overwatering is quite possibly the leading cause of houseplant death. It is an easy mistake to make and for novice growers it can go unnoticed until the problem has progressed too far. Since they are often located indoors, most houseplants have low water requirements and the fact that we see them throughout our day makes it easier for us to give them more than they need. The Catch-22 is the fact that an overwatered plant looks just like a plant that is neglected and under-watered.

When most people see a droopy plant their first reaction is to water it, only causing more harm in the end. When the growing medium is allowed to stay oversaturated the water will become stagnant and the dissolved oxygen that is part of the water molecule will dissipate. Roots need oxygen to survive. When the oxygen is depleted they will die and begin to rot, giving way to diseases like pythium that thrive in such an environment. Without healthy, active roots the remaining moisture will not be taken up by the plant or evaporate quickly enough and the plant will most likely die.


When dealing with an overwatered houseplant the first step is to diagnose how severe the problem is. For less severe cases where overwatering only took place for a short time and the plant is still relatively healthy the fix may be as simple as poking some aeration holes into the medium to allow the moisture to evaporate out. In this case, once the medium is dry resume watering but only in small amounts. Severe cases of overwatering will require more drastic measures.

The best way to deal with drastic overwatering is to repot the plant with fresh potting mix. When doing so I remove any part of the root system that is visually discolored and affected. Roots that are dead or dying will be brown in color and perhaps even a bit slimy to the touch. These roots will not grow back and by leaving them you run the risk of developing disease that can overtake the stressed plant. I also remove any top growth or foliage that is dead or dying. This step may include the removal of quite a lot of the top growth. The key is to focus all of the plant’s energy on the production of new growth.

Removing the dead and decaying components of the root mass will encourage the plant to begin creating healthy new roots. At the time of transplanting I also apply a dose of beneficial microorganisms and liquid kelp extract directly to the root zone. These two products, when combined, will help create a healthy environment for new root growth to become established more quickly. After the procedure is complete the patient will need to be closely monitored for at least a month and watered lightly but frequently to avoid damaging the fresh roots. I also teach whomever it was that sought my assistance the keys to proper watering—the most important of which is to keep the soil moist but not soaking.


The Danger of Overfertilizing Your Plants

Another common issue I come across is in regards to soil fertility and plant nutritional status. Since I work for a fertilizer company I tend to give fertilizer to friends and family in an effort to help them grow more beautiful plants. Sometimes this backfires and the fertilizer is misused much to the detriment of the helpless plant. Plants that end up in my care have often been overfertilized. Houseplants usually have low fertilizer requirements and on average could use a feeding every month or so. When fertilizer is readily available and the plants are always there it is easy to accidently apply excessive amounts. Telltale signs of an overfertilized plant will include discolored leaves that are usually losing their green pigmentation and misshapen leaf or stem growth.

Like any good doctor does, the trick in this situation is to ask as many questions as possible to get a better idea of how to address the problem. Ask about the type of fertilizer applied. Ask how often it was used. Ask how often and how thoroughly the plant is given water. By asking lots of questions you can gain a broader understanding of what condition the plant is in. The more details you have the better job you can do at bringing the plant back to good health.


The first step to take for any plant that is suspected of being overfertilized is to try and flush out any remaining fertilizer from the soil medium with water. Overfertilizing most often results in a buildup of fertilizer around the root zone, resulting in fertilizer lockout, imbalances and a disruption of water uptake. By removing any residual fertilizer remnants, you can create a clean slate to start over from.

I recommend flushing the medium with purified or filtered water such as RO (reverse osmosis). RO water is void of dissolved solids and will not register on an EC (electric conductivity) or ppm (parts per million) meter. So when flushing, I take an initial water EC/ppm reading, which is zero, and then I flush one gallon of RO water through the growing medium at a time. I then collect the last parts of the runoff through the bottom of the pot and measure the EC/ppm again. With severe overfertilization the runoff reading will be rather high. I continue to flush and check the run off solution until the EC readings are below 0.4 or 200 ppm.

After flushing out the residual fertilizer buildup I allow the medium to become almost completely dry before watering again. At that point I water with RO water, allowing a slight bit of runoff to once again help clear the medium. By this time the plants are usually beginning to look healthy again and are regaining their natural green color.

When it is time for the third watering after the initial flush I apply a general-purpose, high-nitrogen fertilizer designed for vegetative growth at half or quarter the label strength. This helps supply the medium with a small dose of nutrients that by this point the plant is ready to use. For the entirety of this process I keep a close, watchful eye on how the plant is progressing and after about the fourth watering the plant is usually ready to be returned to the owner.

Upon return of the plant I always have a conversation with its owner about how much fertilizer should be applied and how often. This is in an effort to help them avoid a similar situation and to make a teachable moment out of the whole ordeal.

It brings me a special type of joy to know that I saved someone’s houseplant from almost certain demise. From time to time the plants put in my care have a particular meaning to the owner. They may have been gifts from a good friend or perhaps inherited from a loved one who has passed on, which several of my houseplants are.

Though they do not boldly interact with us such as an animal would, a houseplant can be as much a member of the family as any pet might be. And when a member of the family grows ill it is our duty to seek proper help and care to get them back to a healthy state. Knowing that I was able to save a plant that is of significance to its owner is why I love being called a plant doctor.


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Written by Kyle Ladenburger | Director of Regulatory Affairs for Age Old Organics & ENP Turf, Freelance Garden Writer

Profile Picture of Kyle Ladenburger
Kyle L. Ladenburger is a freelance garden writer who has worked in the gardening/hydroponics industry for over 15 years. As an avid indoor and outdoor gardener he is well versed in nearly all types of growing methods with an overall focus on sustainability and maintaining healthy soils. He holds a strong conviction that growing one’s own food is a powerful way to change our lives and our world for the better.

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