How to prevent calendula from turning yellow and getting infected?

[aruna_k]

My calendula plants are slowly turning yellow.  Also I see its leaves getting eaten up.  Could you please suggest how do I protect it?  I am also growing marigold near it.  I am worried it may also get infected.  How do I protect them both?  

 

 

 

 this is marigold which looks infected as well as the leaves seem to be getting eaten

[EricL]

Hello @aruna_k 

The chewing pattern on the leaves leads me to believe that it's been eaten by caterpillars or a similar insect. It's also possible that the yellow leaves are the result of either over or under watering. One other cause could be lack of nutrients in the soil or a fungal infection.

Have you fertilized the soil lately? Has your neighbour been spraying any insecticide along the area? In order to check for over watering, I suggest pushing your finger into the soil near your plant about 2cm. If the soil underneath is still wet odds are that it has not yet had enough time to drain away. This extra water actually surrounds the roots of the Calendula and is preventing it from breathing.

This will cause the plant to go limp and expire. I suggest holding off on watering if the soil is still wet underneath. Fungal infection will often leave signs and symptoms on the leaves and insect attacks usually leave an eating pattern on the leaf. They hide very well in the morning, but with enough patience you should spot one or two. I suggest checking under the leaves and at the base of the plant itself. 

I propose using Eco-Organic Garden 250ml Eco-Neem Concentrate Botanical Insecticide on your plants to deter the insect attacks.

Here is a handy step-by-step guide:    How to diagnose a sick plant by @Noelle.          

Let me call on our experienced members @Noelle and @mich1972 for their recommendations.

Please make sure to wear personal protection such as gloves, goggles and an appropriate mask when using the insecticide. Please make sure to follow all the safety precautions indicated at the back of the bottle.  

If you need further assistance, please let us know.

Eric

[mich1972]

https://www.bunnings.com.au/charlie-carp-1l-all-purpose-concentrate-fertiliser_p3018567 

Good afternoon @aruna_k than you for sharing your question and photos with everyone.

To me it looks like caterpillars have been chewing away at your Calandulas and Marigolds. 
If it is , Dipel is a good spray to use. Just make sure you wear protective gear when spraying. Also they need a good liquid feeding to boost the growth. I love to use Charlie Carp. 😃🪴

https://www.bunnings.com.au/yates-40g-natures-way-caterpillar-killer-dipel-insecticide_p2961898 

[mich1972]

 Look at the leaf that I circled. Full of caterpillar Poo !!!!! 

[Noelle]

Hi @aruna_k 

Eric and Mich1972 have given you great advice. You might notice the lower (older) leaves on the calendulas yellowing - this is fairly normal. As the plants grow and start producing lush green growth on top, the older leaves become superfluous - no longer needed - so they may yellow and die off. Nothing to be worried about with that but if the newer, fresh growth starts to yellow then there's definitely a nutritional, watering or disease problem afoot.