Parsley leaves can turn yellow because of root rot or crown rot caused by saturated soil, or as a sign of stress due to a lack of water, however, parsley leaves can also turn yellow as a result of aphid or spider mite infestation.
In the case of parsley leaves turning yellow due to root rot or crown rot, prevention and best practices of care, are better than cure but saving parsley from turning yellow due to aphids, spider mites, and dehydration is relatively easy to resolve.
Keep reading to learn how to implement the solution for each cause of parsley leaves turning and save your herbs!
Parsley Turning Yellow: Root Rot and Fungal Disease
- Symptoms. Parsley leaves turn yellow or brown with drooping or wilting stems.
- Causes. Overwatering, slow draining soils or pots without good drainage, and under watering.
The most common reason for parsley turning yellow is because the soil is too damp as a result of boggy ground, overwatering, or the parsley being planted in a pot without drainage holes in the base.
Parsley prefers moist soil with plenty of organic matter that allows for good drainage.
In soil that is saturated or boggy (as opposed to just moist) there is more risk of fungal diseases such as root rot and crown rot both of which result in the leaves of parsley turning yellow and the stems tend to droop downwards.
How to Save Yellow Parsley In Saturated Soil
- Scale back the watering.
- Improve the drainage by transplanting to a pot or container.
- Ensure parsley is in a pot with drainage holes in the base (avoid using a saucer or drip tray underneath the pot).
The first thing to do if your parsley is yellow is to scale back the watering.
Parsley requires evenly moist soil but the roots do not like to be sat in stagnant water.
However, the underlying cause of yellow leaves is more likely slow-draining soils or pots without good drainage rather than just simply overwatering.
When planting parsley it is imperative to use good compost when preparing the soil or potting mix.
Compost helps to retain moisture yet it still has a porous structure that allows excess water to drain away from the roots, which provides the optimal moisture balance for parsley and helps to avoid fungal disease.
Parsley that is planted in slow-draining soils (such as clay) or in boggy areas, ideally requires moving to pots, containers, or raised beds to help improve drainage.
Pots are better for growing parsley and help to yellow leaves because:
- Pots have naturally more favorable drainage conditions compared to garden soil.
- It is far easier to prepare a potting mix to grow parsley than it is to amend garden soil so that it is better suited for parsley.
Prune back any yellow foliage as low to the ground as you can with a sterile pair of pruners to avoid spreading any fungal pathogens and discard the yellow leaves in a bin or burn them rather than placing them on a compost heap.
By planting parsley in pots and containers with a few drainage holes in the base and ensuring your compost is well draining the parsley can recover although it may be easier to buy some more parsley plugs or seeds and grow it again with better drainage conditions..
Drought Causes Parsley to turn yellow
Whilst overwatering and saturated soil is one of the most common reasons for parsley turning yellow, underwatering and persistently dry soil can also cause yellow leaves.
Under watering is the cause of yellow parsley if :
- The leaves are turning yellow from the bottom.
- Stems are drooping with a general wilted appearance.
- The soil feels somewhat dry to a finger’s depth.
Parsley thrives in compost or soil, rich in organic material that retains moisture, yet has a porous structure to allow excess water to drain away.
If the soil is too sandy or stony without any significant organic matter then the soil can dry out too quickly for the roots to draw up the water the plant requires and the leaves turn yellow as a sign of stress.
Another, perhaps more common problem than underwatering and sandy soils is planting parsley in pots or containers that are too small.
Smaller pots and containers heat up and dry out quickly when in full sun which of course results in dry soil and parsley that is lacking water.
How to Save Yellow Parsley Due to Drought
The key to reviving yellow parsley in dry soil is to ensure that the soil is consistently moist.
Watering: In most circumstances watering parsley once every three days is sufficient to ensure a healthy plant.
However, you should adjust the frequency of your watering to maintain the optimal balance of moisture in your climate to prevent the parsley from drying out.
In the height of Summer during a drought, parsley in a pot may require watering every day to stay healthy.
Compost: In conjunction with a consistent watering schedule, plant parsley in rich compost (multipurpose compost from the garden center is suitable) to ensure the soil does not dry out too quickly.
If you are planting parsley in the ground or in raised beds a water-retaining mulch (such as compost, leaf mold, or well-rotted manure) around the plant can help to preserve moisture.
Pots and containers: The larger the pot the more capacity for soil and the longer it can retain moisture.
Parsley planted in pots that are too small often wilt and turn yellow as a sign of stress.
I plant my parsley in a pot of at least 12 inches across so that they are less susceptible to drought in the heat of Summer and to ensure that the parsley has enough soil to access the nutrients it requires.
Be careful with plastic or metal pots and containers as they conduct heat more readily than ceramic or clay pots.
If the pots heat up too much in the sun this increases evaporation from the soil and can cause parsley to turn yellow.
Plant parsley in a good size pot or container with lots of compost and water regularly and your yellow parsley can start to recover from dehydration over the next few days.
Aphids and Spider Mites
Aphids cause drooping leaves and stems:
Aphids are small green insects that affect a wide variety of plants that are present in most gardens and are usually kept under control by predatory insects.
If your parsley has an infestation of aphids, it can result in leaves that turn yellow and distorted growth.
Aphids are rarely a serious problem, do not do significant damage if addressed, and can be easily removed by hand.
If I have abundant parsley growing then I usually prune away the stems and leaves which are affected by aphids and monitor the plant to ensure that it is free from infestation.
Spider mites cause yellow spots:
If there are small yellow spots on the leaves of your parsley, this is due to an infestation of spider mites.
Spider mites are incredibly small and are barely visible, yet the yellow spots or stipples caused by feeding can be a problem for your parsley leaves.
With a serious infestation of spider mites that is left untreated, the parsley may wilt or have stunted growth.
Spider mites tend to attack plants that are unhealthy due to lack of water, low-nutrient soil, too much fertilizer, or not enough sunlight.
Plant parsley in partial shade to full sun with rich compost to keep the parsley healthy so that it is more resistant to spider mites and diseases.
Prune off any affected foliage and only if necessary use an organic insecticidal soap to spray the leaves in the morning.
Lack of Sun and Poor Soil
Another potential (and easily solved) problem that can lead to yellow parsley is too much shade or poor soil with a deficit of nutrients.
Sunlight: Parsley thrives in partial shade to full sun.
Partial shade is ideal in hotter climates so the parsley can have some respite from intense heat and shade can slow down evaporation from the soil, whereas in cooler temperate climates parsley can grow best in full sun (6 hours of sun per day).
If the parsley is too shaded growth will be slow with drooping stems and some leaves could turn yellow.
Planting parsley in pots is advantageous as you can adjust the location of your parsley until you find the right balance of sun and shade for growing parsley in your climate and avoid the plant turning yellow.
If your parsley is in too much shade, transfer it to a sunnier location a trim back any severely affected yellow foliage and the parsley should bounce back.
Poor Soil: Parsley prefers rich soil with lots of organic matter or compost.
If the parsley is growing in nutrient-poor and perhaps sandy soil, then the plant may not necessarily grow as well as it should and some leaves of the parsley can turn yellow due to a lack of nitrogen.
This problem is easily avoided by preparing the soil well before planting.
Amend the planting area with lots of compost for nutrients and to provide the optimal balance of moisture whilst retaining a well-draining porous structure.
Alternatively, if the growth is relatively slow and the leaves are turning yellow then parsley can benefit from a half-strength application of all-purpose fertilizer.
Generally, additional fertilizer is not necessary for growing parsley if you use good compost however it can help if your soil is naturally sand or stony.
Only use a half-strength application as too much nitrogen can cause parsley to droop and plants suffering from too much nitrogen increases the risk of aphid infestation.
Soil preparation with lots of compost and perhaps a half-strength application of fertilizer can provide all the nutrients that parsley requires and there should be more healthy green parsley leaves as opposed to parsley with yellow leaves.
Is Yellow Parsley Safe to Eat?
Yellow parsley is regarded as safe to eat, however, I would recommend that you trim away any yellow parsley leaves and discard them, as by the time they have turned yellow, the leaves have generally lost all taste and culinary value.
Parsley is easy to grow and relatively inexpensive so always use healthy green leaves for cooking.
- Parsley leaves can turn yellow because of root rot due to soil that is boggy and slow draining, a lack of water, and due to an infestation of aphids or spider mites.
- Boggy soils encourage the conditions for fungal diseases which affect parsley such as root rot or crown rot. Ensure your soil or potting mix is friable and porous so it remains consistently moist but allows excess water to escape to avoid root rot. Plant parsley in pots with drainage holes in the base rather than slow-draining garden soil.
- Parsley requires evenly moist soil, so if the soil dries out then the leaves turn yellow as a sign of stress. Water parsley once every three days, plant it in larger pots and prepare the soil with compost to help retain moisture.
- Aphid and spider mite infestations can cause parsley to turn yellow and droop. Remove aphids by hand and trim back any affected growth.