Why Are Zucchini Leaves Turning Brown?

Seeing zucchini plants growing well is great, but not until some of the leaves are browning. It is a bit concerning when you see your healthy zucchini plants have those brown leaves.

But what are some possible reasons green leaves on zucchini turn brown, and what can you do to prevent it from happening?

Why Are Zucchini Leaves Turning Brown?

1. Fertilization Problem

Applying fertilizer, especially chemical fertilizers, can cause brown leaves on the zucchini plant. Chemical fertilizers are not organic, and when too much chemicals are added to the soil, they can affect zucchini plant growth.

Chemicals can burn the plant’s roots, and when the roots are damaged, the plants cannot get enough water and nutrients from the soil.

When plant roots are damaged, they are not functioning well, leading green leaves to turn brown.

So being careful in fertilizing the zucchini plant is the key to preventing giving too much fertilizer to the plant. If you are practicing organic gardening, it is better to use organic fertilizers like compost.

Organic fertilizers are more eco-friendly and are a little bit safer to use, especially for your plants.

2. Pesticide Damage

Pesticides help control pests on zucchini plants, but too much can affect their growth.

Pesticides can cause burns on the leaves of zucchini which makes them brown. The chemicals affect the leaves, and aside from color, sometimes they also change in form.

Pest infestation sometimes happens, and pesticides are used to eliminate those pests. There are chemical pesticides, and it is not great when applied too much.

Also, when the weather is too hot, it is not good to apply pesticides because there is a high chance of getting leaf burn during this time. Apply pesticides early in the morning or late in the afternoon to prevent pesticide damage.

3. Herbicide Damage

When there are many kinds of grass in the garden, some gardeners use herbicides to control them. But herbicide damage can also happen when applied the wrong way.

Herbicide can burn the zucchini leaves, but when you lessen the application, it can prevent brown leaves to your plant. Or Instead of using herbicide, why not just try to remove those grasses using your hand.

You can also use some gardening tools to help you remove those grasses.

4. Extreme heat

Usually, the hottest time of the year is during summer. The weather is hot and extreme heat can cause zucchini leaves to turn brown.

Depending on the location, some places are experiencing hot weather that affects plant leaves. The zucchini plants grow long and wide, and you cannot move them in a shaded area, especially when planted in the ground.

The zucchini vines are growing wide, and one way to keep the zucchini plants hydrated is to give them enough water.

5. Lacking Water

Zucchini plants need at least 1 inch of water per week, and brown leaves may appear on the plant when they lack water. Give the plant enough water to stay hydrated because it will make them keep thriving.

You can check the soil by pressing your finger two to three inches, and when it’s dry, you need to water your zucchini plants. The plants will need more water when the weather is hot.

But when rain is available, you don’t need to water your zucchini because giving additional water to the plant can cause overwatering.

6. Overwatering

Overwatering can cause some problems on the plant, like yellowing leaves, drooping leaves, and brown leaves. It can also affect the overall growth of the zucchini plant.

Overwatering can happen when too much water is given to the plant or when it rains for consecutive days. The water can cause root rot on zucchini plants, making leaves turn brown.

Just give the right amount of water and try to make waterways to prevent your plants from getting flooded, especially when a heavy rain comes.

7. Transplant Shock

Transplant shock can also happen when the zucchini plant is moved to a new soil or pot. When the zucchini plant is already established and big enough, it can suffer transplant shock.

Usually, zucchini plants are not being transferred when they are already growing. But in case they are moved, shock can happen.

The best time to transplant zucchinis is when they are in the form of seedlings. Seedlings are not prone to transplant shock since they are still small and can be transplanted well.

8. Pests

Pests like thrips, aphids, and squash bugs can cause some damage to the plant. You need to control these pests so that the zucchini will stay healthy.

Just make sure not to apply too much pesticides because they can cause burns to the plant.

9. Aging leaves

Those young leaves of the zucchini plant will soon become old. The green leaves will turn yellow and brown and drop to the ground. It is a cycle that is normal for this plant and other plants.

If there are only a few brown leaves on zucchini, they are probably just aged leaves. By monitoring your plants regularly, you can tell if they are aging leaves or not.