Why Are My Dahlia Leaves Turning Yellow?

Have you ever seen a dahlia plant that is full of beautiful, deep red flowers but has yellow leaves? If so, then this blog post will answer your question.

Dahlias are one of the most popular garden plants in North America and there are many reasons why they turn yellow.

This article goes over some common causes for yellowing leaves on dahlias to help you get them back to their original color!

Why Are My Dahlia Leaves Turning Yellow?

Dahlia leaves turn yellow because of overwatering or a lack of nutrients in the soil. You see, dahlia plants need soil that contains lots of nitrogen, iron, and magnesium. The plant also needs to receive the correct amount of water, as too much will result in root rot or fungal issues.

Dahlia Leaves Turning Yellow from Overwatering

The correct amount of water is needed for a dahlia plant to thrive. If the soil is too wet or damp, it can cause root rot and increase your chances of losing your beloved garden plants!

If you notice that the leaves on your dahlia begin to turn yellow from over-watering, then you need to take action immediately by not giving any more water and creating a watering schedule.

Dahlias usually need about one inch of water per week, but make sure to check the soil by dipping your finger into the ground. If it is dry, then you can water them; if the soil is wet or damp, do not give any more water!

Using a moisture meter will allow you to get even more accurate with your dahlia watering schedule.

Dahlia Leaves Turning Yellow from Low Nutrients in the Soil

If your dahlia leaves are turning yellow, but you know that it is getting enough water and there isn’t any root rot or fungus damage, then this may be caused by low nutrients in the soil.

Your plants most likely need more nitrogen to get their beautiful color back! You can do this by adding fertilizer into your garden every two weeks during the growing season of summertime. If you have tried fertilizing them with no luck at all, then try mixing some composted manure into the soil as well for best results!

I use MiracleGro, which is a leading brand of both outdoor and indoor plant fertilizers. It nourishes plants with everything they need to grow strong and healthy, including macro-nutrients like phosphorus, potassium, nitrogen, and chelated micro-nutrients that nourish the roots.


Should I cut yellow leaves off dahlia plant?

Yes, you should cut off yellow dahlia leaves. Otherwise, the leaf will turn brown and fall off on its own!

Will slugs cause yellow dahlia leaves?

No, slugs will not cause yellow dahlia leaves. They tend to just chew holes in the leaves!

Is too much sun why my dahlia’s leaves are turning yellow?

Yes, if your dahlia is getting too much sunlight or direct light each day without any shade at all, it will cause the leaves on top to scorch. Nearly all plants are at risk of getting sunburn.

Are yellow dahlia leaves poisonous?

No, they are not poisonous to humans or pets. They do contain a sap that can irritate skin though, so you may want to take precautions when handling them.

Does a lack of nitrogen cause yellow dahlia leaves?

Yes, a lack of nitrogen in the soil can cause yellow dahlia leaves. The plant needs lots of nitrogen to thrive, but if it doesn’t receive the correct amount then its leaves will turn yellow!

Will too much water cause my dahlia’s leaves to turn yellow?

Yes! Dahlias are very sensitive when it comes to receiving enough or too much water. You should always check the soil before watering your dahlia to make sure it is not too wet or damp. If this is the case, then do not water them!

Are my dahlia leaves turning yellow from being frozen?

Possibly! If you live in a colder climate and have had several harsh touches of frost, then the leaves on your dahlia may have been frozen. When this happens, it can cause the leaves to change color!

Where can I buy dahlia plants?

You can find them anywhere from your local garden center or home improvement store! You can also order them online at places like Home Depot and Lowes.

Will yellow dahlia leaves turn green again?

No, it is unlikely that yellow dahlia leaves will turn green again. However, taking action will stop the other leaves from turning yellow.


In conclusion, dahlias are beautiful flowers that many gardeners want to grow. If your dahlia leaves turn yellow, it could be due to overwatering or a lack of nutrients in the soil.

You can fix the issue by adding more nutrients, like organic compost or fertilizer. Also, make sure you are watering the plant correctly by using a deep but infrequent irrigation method (such as drip).

If these solutions don’t work after some time, then your dahlia leaves turning yellow may be caused by root rot or fungal issues. If this is the case, it’s best to contact an expert for help on how to get rid of them!

Thank you for reading my blog post on why are my dahlia leaves are turning yellow. You should not that dahlia leaves sometimes curl, so check out my blog post if you are experiencing this.? I hope that with this information your beautiful flowers will return back to their original color soon!

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