Nasturtium turns yellow if it doesn’t get adequate sunlight. Nasturtium also turns yellow if it’s watered improperly. Nasturtium foliage turns yellow if there’s a severe infestation of Aphids/Whiteflies. Nasturtium also turns yellow due to Herbicidal damage. Often, the yellowing of the foliage is because of aging.
Tropaeolum is a genus of various species which are annuals and perennials. Tropaeolum is commonly referred to as Nasturtium.
Nasturtium is grown in the garden for its colorful blossoms. All parts of this plant are edible and are commonly used in salad.
Nasturtium runs into some problems if proper conditions are not present. Let’s see why the leaves turn yellow.
Why are my Nasturtium leaves turning yellow?
Nasturtium leaves turn yellow if the plant doesn’t get adequate, direct sunlight. Nasturtium also turns yellow if the plant gets more water than needed. Nasturtium also turns yellow due to underwatering.
Overwatered your Nasturtium?
Nasturtium leaves turn yellow if the plant sits in waterlogged conditions for too long. Overwatering and heavy soil lead to waterlogged conditions.
Are you growing your Nasturtium in a pot? If yes, does the pot have drain holes? Does the potting mix drain excess water efficiently?
Nasturtium loves water but it doesn’t like to sit in waterlogged conditions. Increase soil drainage by adding Perlite to the regular potting mix.
If it is growing in the ground, see why it’s getting a lot of water. Does the rainwater collect near your Nasturtium?
Is the soil too heavy? If the soil is heavy, adding Perlite to it helps.
Water your Nasturtium only when the top inch of the ground/pot is dry. Check it with bare fingers if necessary.
Stop watering your Nasturtium immediately if you diagnose the issue to be overwatering.
Tip: Get a soil moisture meter if you are unable to water your plants properly.
Nasturtium also turns yellow if the plant doesn’t get enough water. Nasturtium thrives only when it’s watered abundantly.
Check the soil with your bare fingers and water when it goes dry up to an inch. Don’t let the soil go bone dry between the watering sessions.
Nasturtium leaves wilt and turns yellow if the plant’s underwatered. The leaf tips dry out and turn brown. The growth is stunted.
Nasturtium fails to produce blossoms if it’s underwatered. This is why check the soil often and water when needed.
Nasturtium: lack of sunlight
Nasturtium leaves turn yellow if the plant doesn’t get enough sunlight. Nasturtium thrives in bright sunlight.
Nasturtium doesn’t survive in shade or even partial shade. They need a lot of sunlight to thrive in the garden.
Improper sunlight causes foliage yellowing in Nasturtium.
How many hours of sunlight does Nasturtium need?
Nasturtium needs at least 6 hours of direct sunlight per day. The leaves only turn yellow if the plant gets shade throughout the day.
If it gets partial shade, the blooming will be hindered to an extent.
Here’s how to fix this
- Move the plant to a brighter spot if the plant is still young.
- See why your Nasturtium’s getting shade. Is some tree blocking the sunlight? Prune off such tree accordingly.
- The west-side of your house may recieve bright sunlight. Such plants need to be in the west-side of your house.
Herbicidal damage on Nasturtium
Nasturtium leaves also turn yellow if Herbicide gets onto the Nasturtium foliage accidentally. The damage also shows on the shoots, fruits, and flowers.
The leaves turn yellow and decline in this situation. Accidental downwind contact from broad-leaf herbicides can be very damaging.
Your Nasturtium will recover from this damage if it’s just a minor exposure.
If your Nasturtium is not recovering even after a while, then know that it has been exposed to excess Herbicide.
This is why it’s crucial to abstain from spraying herbicide when it’s windy outside.
Natural yellowing of the foliage
The older leaves of Nasturtium turn yellow naturally, so you need not panic if you see some old leaves turning yellow.
If there aren’t any other symptoms other than yellowing foliage, you need not worry at all. Your plant is merely aging.
Should I remove yellow Nasturtium leaves?
Yes, do remove yellow Nasturtium leaves. By doing this, you’ll prevent disease spread if there is indeed an infection.
Removing yellow leaves also encourages new growth in your Nasturtium. However you see it, it’s only beneficial to the plant.
But be careful when you prune your plant. Disinfect the tools before and after working on plants with yellow leaves.
Related: Why is Nasturtium not flowering?
Nasturtium leaves yellow spots
Yellow spots are seen on Nasturtium due to Aphid infestations. Whiteflies also cause foliage yellowing in Nasturtium.
Aphids and Whiteflies feed on the undersides of the plant’s leaves. They live by sucking the plant sap from the victim plant.
Their feeding habits cause yellow spots on the Nasturtium foliage. Leaves get distorted thanks to these pests.
Tip: Inspect the Nasturtium foliage often to identify pest infestations early on.
Aphids and Whiteflies secrete a sticky substance called honeydew. Honeydew paves way for fungal infections, leading to ‘Sooty mold’.
Ideally, you need to identify these pests early on, before they become severe infestations. Hang yellow, sticky cards around your Nasturtium to identify these pests early on.
Nasturtium attracts aphids, so much so that, the plant is recommended as a trap for aphids.
Ways to control Aphids/Whiteflies on Nasturtium
- Dislodge aphids/whiteflies by spraying water forcefully on affected parts of Nasturtium.
- You can also wipe these pests off your plant usind a cotton swab/cotton ball that’s dipped in rubbing alcohol.
- Spray Neem oil on the affected parts of Nasturtium to eliminate these pests organically.
- If the infestation is severe, spray Insecticidal soap solution on the affected parts. Spray the soap solution once more after a fortnight to get rid of them for good.
Happy Gardening 🙂