Parsley is a reasonably easy-to-grow annual herb. The simplicity of growth comes with a few hurdles, though. One of the biggest maintenance issues is when the parsley leaves turn yellow.
This herb can fade from lush green to pale yellow due to a few fixable stressors. Today we are going to talk about the reasons (with quick fixes) for Parsley leaves turning yellow.
The reasons include nutrient imbalance, fungal infection, bad soil composition, and an infestation caused by insects and/or pests. Luckily, the majority of these problems aren’t too difficult to correct.
That is, of course, if you spot them early. Let’s look at the warning signs you should be aware of and how to prevent or treat these types of concerns.
Table of Contents
Parsley Leaves Turning Yellow: Reasons and Solutions
If you find that the leaves of your parsley are starting to turn yellow, don’t fret; they can be corrected as long as you know what to look out for and see the warning signs sooner rather than later.
It’s worth noting that the outer leaves generally start to discolor first.
You can use the spread of discoloration from the outermost parts to in as a guide to know how badly stressed your parsley plant is.
Let’s look at some of the most common reasons that your parsley leaves may turn yellow. Once we have established the cause, we can treat it with the appropriate solution. The main causes are as follows:
Nutrient Imbalance
When using nutrients to nourish your plants, it’s quite easy to accidentally give them too much. The results don’t show straight away, so you may add a little more than usual, and the leaves start to burn.
The scolded leaves start yellow, then turn more brown as they slowly dry out and die.
In contrast, adding too few nutrients can cause the leaves to turn yellow via a lack of nitrogen. Nitrogen is one of the key ingredients in most fertilizers, alongside potassium and phosphorus.
It helps allocate energy when a plant needs to optimize its yield. Some other signs of an imbalance include leggy stems, abnormal or stunted growth, and no fruits (in this case, poor herb formation)
How to Solve Nutrients Imbalance?
There are a couple of ways to correct this issue. Firstly, it’s worth noting that the root system of the parsley herb is quite long, so any fertilizer you apply will eventually be gobbled up by the plant somewhere inside the pot.
Knowing this fact, the first thing you should do is flush the soil periodically.
You can dilute the fertilizer and make it less potent by doing so. Otherwise, when it does come time to fertilize, dilute the solution before applying it. It will do more damage by having too much fertilizer than too little.
Fungal Infection
Fungal infections can occur due to a range of different contaminants landing on the plant and can induce some severe damage if not discovered early.
Here are some more common fungal issues that can cause parsley leaves to turn yellow.
- Septoria leaf spot – Can be distinguished by yellowing and even yellow/tan/brown spots as well as a yellow edging on the parsley leaves. Infested seeds usually bring it about. Overwatered plants and cross-breeding can also kick this infection into full gear. Wet conditions, including wind-driven rain, dew drops, and overhead irrigation,, are the main culprits.
- Stemphylium fungus – This fungal disease has been known to affect garlic, leek, onion, and asparagus. Only recently, though, has it been discovered amongst parsley leaves. In its early stages, it will produce yellow spots. If untreated, those spots will begin to turn gray, and the whole leaf will start to pale and yellow. The main cause is not removing excess water around the stems and the water splashing up onto the leaves. Especially in humid conditions where the moisture can settle all over the plant.
How to Treat Parsley Fungal Infection?
- Septoria leaf spot – The best course of action is to use a general fungicide. Great results have been achieved by using some kind of copper diammonia diacetate complex. You can also use a copper octanoate/copper soap if the infection is only mild. If all else fails, you should completely remove the plant and dispose of it far away from any other plant. This will ensure the infestation doesn’t affect anything else.
- Stemphylium fungus – It’s best to treat this disease in cool, dry weather. Using a solution that includes the active ingredients azoxystrobin + difenoconazole, boscalid + pyraclostrobin, chlorothalonil, iprodione, mancozeb, and prochloraz is the most effective. A combination of these will ensure that the disease is wiped out and cannot respawn unless infected from another outside source.
Poor or Slow Draining Soil
Having the right soil is essential for any plant. If the soil in which your parsley is growing contains a high overall volume of clay, weeds, or even some chemicals, it will struggle to grow.
Not only will the growth become stunted, but the available nutrients won’t be able to move around freely.
As this occurs, a lack of nitrogen will ensure that the parsley leaves turn yellow. The same applies to any other soil that doesn’t allow adequate drainage and/or aeration.
The roots will suffocate from not only a lack of food but also a lack of available moisture. Unfortunately, your parsley will suffer a slow death if untreated.
How to Solve This Problem
The beauty of this problem (if there is such a thing) is that it is pretty simple to adjust. The best way to deal with poor or slow draining soil is to report or rehome (if grown in the garden).
Remove your parsley from the growing container, and gently rinse the roots to clean away the soil/clay.
Then add some new, better-draining materials such as compost, rotted chicken, or cow manure. If you are replanting in the ground, turn the top 30cm of soil over to air it out and remove any rocks or debris.
Then add 1 part compost/manure for every 2 parts potting soil used. Give it some fertilization and water on arrival, and tend to it as normal again.
Insects and Pest
There are 2 main pest culprits when it comes to the leaves of parsley turning yellow. They are spider mites and aphids.
- Spider mites – Feed on the parsley leaves. They create yellow marks or “stipples” as they suck the moisture out of the parsley plant. They are extremely small and almost impossible to spot. If left unattended, the parsley will have its growth stunted and wilt. Spider mites tend to latch onto plants that are unhealthy. This can be due to an insufficient water supply, lack of obtainable nutrients in the soil, and over-fertilization.
- Aphids – Aphids cause the same amount of carnage as spider mites. They suck on the leaves, leaving bite marks that start yellow and slowly eating away at the affected area. Aphids also leave a sticky honeydew which attracts ants. They are slightly easier to find as they are a little bigger and green in color.
Solution
Spider Mites
One of, if not the best, solution is to mitigate the problem before it arises. Keep your plant healthy by planting in full sun but allowing partial shade as respite.
Additionally, plants with organic-rich soil mixed with compost or manure ensure that the parsley has no problems staying alive and well.
This will make your plant more resistant to the mites and their diseases. Alternatively, if the infestation hasn’t been discovered early enough, trim any foliage that has been affected and apply an organic insecticidal soap or neem oil via a spray bottle.
Aphids can be controlled by inviting predatory insects to help ward them off. Bugs such as Ladybugs, Green lacewings, Aphidius colemani, and Aphidius ervi love munching on aphids for breakfast, lunch, and dinner.
Planting other attractor plants such as dill, fennel, or even lavender close by will attract these predators, which will help keep the aphids in check.
Alternatively, they can be removed by dabbing cotton buds with rubbing alcohol and prodding at them. It’s also a good idea to rub around the affected area to ensure they don’t return.
Other General Maintenance Problems
Overwatering or Underwatering and How to Solve
- Overwatering – Overwatering your parsley will cause the leaves to turn yellow by rotting out the roots. Due to the elongation of the parsley’s root system, the very bottom tip can grow and eventually reach down to the bottom of the pot. If an excess of the water lays down there, they will pretty much be bathing in the water and rot out as a result. Overwatering can be made even worse by poor soil, which doesn’t allow drainage or aeration.
- Quick Fix – If the plant is already showing strong signs of root right via yellowing the leaves, it’s best to report. Carefully remove the parsley from its pot and investigate the condition of the root system. Black and brown roots cannot be saved, but if they are still white, then there is hope. Clip off any dead smaller roots and rinse away all of the soil. Then create a new soil mixture before replanting again. It’s always a good idea to water sparingly. Check the top inch of soil has no moisture before adding any extra water.
- Underwatering – Under Watering can also discolor the leaves by making them dry out due to the deficiency. The difference is more the texture. Overwatering causes more moist yellow leaves and underwatering causes more dry yellow leaves. Yellowing is the early stages of wilt and death, if left unattended, they will then turn brown then dry out completely and die.
- Quick Fix – Always check the condition of the soil while watering. If necessary, use a chopstick or something a little longer to poke down the soil. Try to gauge how wet or dry it is. If it’s bone dry, give it some water. Additionally, check the overall condition of the soil; it may be that the water is draining away too fast for the parsley to soak it up. If this is the case, add some organic matter to act as a sponge. This will ensure that the water can be held for longer periods.
Lack of or too much sunlight and How to Solve?
Too much sunlight
Too much sunlight can see your party plants to become burnt and turn the leaves yellow, especially if they are placed in direct sunlight. Having them out in the harsh sun’s UV rays (even if it doesn’t seem that way) can not only burn the leaves but also dry them out, causing them to turn yellow.
Quick Fix – Add a shade cloth or covered area so your parsley plants aren’t subject to too much direct sunlight. Parsley is better grown in pots as they can be moved around to mitigate the risk of any issues caused by climate, weather, etc.
Lack of sunlight
Plants need sunlight, among other ‘ingredients’ for photosynthesis. Photosynthesis creates a plant’s energy. Parsley requires at least 6-8 of indirect sunlight per day to gain energy to grow.
So a lack of sunlight will slow their growth rate and not allow them to produce lush green leaves. Instead, they can form yellowish leaves as a result of the deficiency.
Quick Fix – Simply move the parsley plant somewhere that it can bathe in at least 6-8 hours of indirect sunlight per day. E.g., a window sill, covered porch, etc. If this is impossible to do where you live, consider some grow lights that can simulate the sun.
Why Blight May Cause Parsley Leaves Turn Yellow?
Blight is also known as gray mold. It is brought on by a pesky type of fungus called Botrytis. The leaves can turn yellow and form dark spots. This fungus is similar to a leaf spot in appearance.
Once the disease establishes itself, the yellow leaves can change to other colors. These include brown and, in worse cases, black spots on the leaves.
If left unattended, the leaves can form whiteish/gray fungal growth all over the affected leaves. Hence the name. The leaves simply cannot heal if the issue is not resolved early.
They will wilt and die. As the disease takes over the whole plant, it will also suffer at its hands of it.
Quick Fix–
Firstly, isolate the plant well away from other plants so the disease can’t spread. Clip away any areas that have been heavily affected. Use a treatment such as neem oil or a copper-based fungicide on the affected area. Avoid getting water onto the leaves as it recovers. Keep an eye on the plant over the next week to see if the disease has started to clear out. Repeat the process if necessary.
Why Transplant Shock May Cause Parsley Leaves Turn Yellow?
When transplanting a parsley plant, there is a risk that it will go into shock. This can cause the leaves to turn yellow as a result. The root system of a parsley plant is elongated, which can be problematic due to its delicate nature. A long, twine, delicate root system needs to be cared for and treated gently. The roots are also extremely sensitive.
Quick Fix –
When transplanting a parsley plant, it’s best to have a longer (higher) pot. Gently pull up the plant and rinse off the old soil. Try to keep the whole plant steady as it can easily tear apart due to its sensitivity.
Make sure you have good quality, well-draining soil ready to be planted. Gently lower the root system first and slowly pack the soil around the plant as you work your way from the bottom of the pot to the top.
Parsley Plant Growing and Maintenance Tips
We hope that the abundance of well-researched information presented in this article has been so far helpful for you.
There are, however, a few more growing and maintenance tips that can be implemented to help yield some all-around good quality parsley. They are as follows:
- Choose an area that is sunny earlier in the day but has shade in the afternoon for optimal growth. Parsley loves the sun, 6-8 hours of it. But they do, however, prefer indirect sunlight, so shading is essential. Especially in warmer climates.
- Choose a nutrient-rich, well-draining soil with a pH of around 5.5 to 6.7. It’s easy for a parsley’s root system to get stuck bathing in pooled water at the bottom of a pot. Using several inches of aged organic compost or manure mixed in with your potting mix is optimal for long-term sustainability.
- Offer enough water so that the soil is moist but not flooded. This will only cause issues with rotting roots.
- When it comes to harvest, trim the outside stems and/or leaves first and work your way in. Never remove more than ⅓ of the plant at once and let it completely regenerate before cutting from the same spot again.
Frequently Asked Questions (fAQs)
Should I cut off yellow parsley leaves?
Parsley grows extremely fast, as long as it is harvested correctly. So, it’s quite ok to remove any yellow leaves. They are edible but don’t taste the best. It’s better to let the green ones regenerate and use them instead.
Can I eat yellow parsley leaves?
Yellow leaves are safe to eat, but they don’t taste as green or fresh. It’s better to remove them and go for the green ones instead.
What is the best fertilizer for parsley?
The best fertilizers for parsley are organic varieties such as fish and kelp, blood meal, bone meal, coffee grounds, epsom salt, fish emulsions, compost, and manure. You need to ensure you know the soil’s pH first, so you aren’t adding the wrong kind of fertilizer. Parsley thrives best with a pH of between 5.5 and 6.7. Alternatively, a 5-10-5 commercial fertilizer works best when growing parsley.
Conclusion
So as we have discovered, the leaves of the parsley plant can turn yellow for a number of reasons. Whatever the case, it is when the plant is under some kind of stress within its growing environment.
Luckily, the problems can be corrected as long as they are identified sooner rather than later.
We hope this lengthy article has been packed full of information and helped answer any questions you may have had. Thanks for tuning in, and we’ll see you on the next one! Happy growing!
