Why Are Arugula Leaves Turning Yellow?

Arugula is a green leafy vegetable and it will be frustrating when the leaves become yellow. Arugula is delicious to consume when they are fresh and green but when the leaves are yellowing it’s not good to eat. What are some causes why arugula leaves turn yellow?

Arugula Leaves Turning Yellow

Watering Problems


Overwatering can cause yellow leaves on the arugula. The arugula cannot handle too much water and it causes stress. Overwatering can happen when too much water is given to the arugula or it can happen when heavy rains come.

A watering can or a garden hose can be used to water your arugula but just give the right amount of water. Check the soil moisture before watering the arugula if the soil is dry you can water it but if the soil is moist you don’t need to.

There are ways to check the soil moisture like pressing your finger a few centimeters in the soil, pressing a screwdriver, or using a soil moisture meter. Any of those ways can be used to know the soil moisture and gives you an idea of when to water the arugula.

A well-draining soil is also helpful to avoid waterlogging. Sometimes heavy rainfall comes to your location and you must make good waterways to prevent your arugula from getting flooded. Too much water can cause root rot which makes leaves yellow but when it’s prevented the leaves are safe.

Lacking Water

Lacking water can also cause yellow leaves on the arugula. Water is essential for the arugula to grow well which helps it to grow healthy and able to produce more fruits. Water the arugula regularly and make a watering schedule so that you know when to water your plant.

The arugula needs more water when the weather becomes hot. With the right amount of water, it can make the plant cool and hydrated. The arugula needs at least 1 inch of water per week. 

Aging Arugula Leaves

It is normal to see yellow leaves on any plant or tree. Commonly these yellow leaves are aging leaves. It is normal to see these kinds of leaves even on arugula because it is part of their growth.

It is a cycle for the arugula leaves to grow and then get old. The young leaves will grow and after a few weeks or months, they turn yellow, and eventually, arugula leaves turn brown.

If there are only a few yellow leaves on the arugula then probably they are just aging leaves but if there are too many yellow leaves you need to analyze and observe if there are other reasons causing the problem.

Nutrient Deficiencies

Nitrogen is an important nutrient needed by the arugula to keep its leaves growing and staying green. Nitrogen deficiency causes yellow leaves on the arugula and to prevent it from happening you need to make the soil rich in nitrogen. You can use a soil tester to check the soil and then apply the right amount of nitrogen.

The arugula needs nitrogen because this nutrient helps the production of chlorophyll in the leaves. Chlorophyll helps the arugula convert sunlight into food which makes helps it grow better. Aside from nitrogen, Iron deficiency can also cause leaves to turn yellow on arugula.

There are many kinds of fertilizer and some of them have nitrogen and iron along with other nutrients which are helpful for the arugula to grow well if applied.

Transplant Shock

Moving your arugula to a new location can cause transplant shock. Transplant shock causes stress which can lead the leaves to turn yellow. Shock commonly affects mature arugula and not those young arugula.

You need to be careful in transferring mature arugula because transplant shock may happen. Water the arugula immediately just after transplanting. You will need to wait for a few days or weeks and monitor how the arugula goes especially when they suffer transplant shock.

Usually, those young arugula don’t get transplant shock. They just need to be watered after transplanting and they will grow just fine. 

You Overfertilized Arugula

You also need to be careful not to overfertilize arugula. Too much fertilizer can burn roots and when roots get damaged it can cause yellow leaves. When roots are damaged the arugula cannot get enough water and nutrients because the roots are not functioning well.

Avoid overfertilizing arugula especially if you are using chemical fertilizers because they can burn arugula roots.

If you are practicing organic gardening then you can use compost and other organic fertilizers. You can also add mulch to keep soil moisture.

Arugula Is Lacking Sunlight

The arugula needs sunlight to grow healthy and be able to produce more food. Grow the arugula in a place where it can get a lot of sunlight so that the yellowing of leaves can be prevented. The arugula needs at least 6 hours of sunlight per day.

Avoid growing the arugula near tall trees because it may not get enough sunlight because those tall trees may block the sunlight. When the arugula is getting consistent sunlight per day it will grow healthy and can give you a lot of fruits.

Weather Changes

Weather changes can also affect the arugula which may lead to its leaves turning yellow. Even if the arugula needs more sunlight, extreme heat is not good. Too much sunlight can affect the leaves which can make them yellow. Keep the plants hydrated when the weather becomes hot.

Pests And Diseases

There are pests and diseases that may also cause yellow leaves on your arugula. You need to monitor your arugula and see if there are pests and diseases that attack your arugula. In that way, you can protect them and you can use pesticides or fungicides to get rid of them.