Why Are Cauliflower Leaves Turning Yellow?

Cauliflowers can take about 50 to 100 days to grow and harvest but there are a few problems that you may encounter sometimes like the yellowing of leaves. When cauliflowers have a lot of yellow leaves they will not grow healthy and cauliflowers might not grow well. What are the causes why this happens?

Cauliflower Leaves Turning Yellow

Watering Problems


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

A watering can or a garden hose can be used to water your cauliflower but just give the tree the right amount of water. Check the soil moisture before watering the cauliflower 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 cauliflower.

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 cauliflower 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 cauliflower. Water is essential for the cauliflower to grow well which helps it to grow healthy and able to produce more fruits. Water the cauliflower regularly and make a watering schedule so that you know when to water your plant.

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

Transplant Shock

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

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

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

Aging Cauliflower 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 cauliflowers because it is part of their growth.

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

If there are only a few yellow leaves on the cauliflower 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 cauliflower to keep its leaves growing and staying green. Nitrogen deficiency causes yellow leaves on the cauliflower 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 cauliflower needs nitrogen because this nutrient helps the production of chlorophyll in the leaves. Chlorophyll helps the cauliflower to convert sunlight into food which makes helps it grow better. Aside from nitrogen, Iron deficiency can also cause leaves to turn yellow on cauliflower.

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

You Overfertilized Cauliflower

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

Avoid overfertilizing cauliflowers especially if you are using chemical fertilizers because they can burn cauliflower 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.

Cauliflower Is Lacking Sunlight

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

Avoid growing the cauliflower near tall trees because it may not get enough sunlight because those tall tress may block the sunlight. When the cauliflower 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 cauliflower which may lead to its leaves turning yellow. Even if the cauliflower 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 cauliflower. You need to monitor your cauliflower and see if there are pests and diseases that attack your cauliflower. In that way, you can protect them and you can use pesticides or fungicides to get rid of them.