Why Does My Sunflower Have Yellow Leaves: Diagnosing And Fixing Flower Issues

A picture of lightly brown-spotted sunflower leaves.

Sunflowers are known for their vivid yellow petals, but why does your sunflower have yellow leaves? Is that normal, or should you be worried? Cultivating sunflowers doesn’t have to be difficult, but it does take a little basic knowledge. Certainly, if you want to grow healthy plants, the leaves need to be large and green. Overwatering or clumpy, clay-filled soil is usually the culprit when your leaves go yellow. You can check the base of the flower stem for signs of yellowing as well. If the stem is also changing, then your plant is getting more water than it needs. Germinating sunflower seeds takes a lot of water, but once they sprout, you should cut back substantially. I will walk you through everything you need to know about sunflower leaves, plus I’ll offer some helpful tips on watering to keep those blooms beautiful. With a little extra care, you can revive those failing blooms and keep your garden gorgeous.

Why does my sunflower have yellow leaves? Your sunflower has yellow leaves because you are overwatering. When the leaves turn pale and shrink, it’s a sign that your plant is drowning due to poor soil drainage. Fortunately, you can take off the dying leaves and cut back on your watering to help the flowers grow healthier.


How Often Should Sunflowers Be Watered

Proper watering will help you avoid having to ask questions like, ‘why does my sunflower have yellow leaves?’ However, sunflowers are tricky. Most plants will start to discolor and dry out when they don’t have enough water. However, sunflowers’ leaves can yellow from overwatering.

When you first germinate the seeds, watering a little bit daily to keep the soil moist is crucial. Yet, once they are growing, your sunflowers do not need much from you. Water sunflowers every week. They only need about an inch of water, so please don’t leave a hose running in a sunflower bed.

If it rained, you would need to modify your watering schedule. Although sunflowers like a good drink, you need to allow the top inch of soil to dry between waterings. Unless you live in the desert, most sunflowers won’t need any additional water.

Ensure that the soil you use drains well, or your flowers will get waterlogged. The yellow leaves are a sign that the plant is sucking up too much liquid. You can repot some flowers and cut back on watering to improve their chances.

Pro-Tip: Stop watering sunflowers once the heads are fully developed and have started to brown. They are ready for harvest, and adding more water isn’t going to give the flowers anything useful. Worse still, it could create a perfect environment for bacteria, mold, mildew, and fungus to develop.

Are you ready to try out sunflower growing but unsure which type you want? I recommend a Sunflower Garden Grow Kit from Amazon. With five stunning varieties of sunflowers, black oil standard, chocolate cherry, lemon queen, red velvet queen, and teddy bear, you can easily learn what grows best in your zone. More importantly, these non-GMO seeds have a ninety percent germination rate. Learn all about this flower kit by clicking here.

How Often Should I Feed Sunflowers

Sunflowers like to eat. You would, too, if you grew as fast as they do. These tall plants need very regular nutrients to stay healthy.

Diluting a liquid feeding solution in a couple of gallons of water weekly may help flagging sunflowers. Remember not to overfeed as it can cause more harm than good for your plants. As they grow, digging a small, eighteen-inch around and four-inch deep moat at the base of each stalk can help you deliver food and water more efficiently.

Additionally, your sunflowers need a lot of light to photosynthesize their own food. Place sunflowers to get no less than six hours of direct sunshine per day. If you grow indoors, set your LED grow lights for six to eight hours.


What Do Overwatered Sunflowers Look Like

An overwatered sunflower will typically have yellow leaves. The color variation doesn’t have to be extreme. It may begin as a slight paling and come on unevenly. There are other signs to watch out for as well.

All sunflower heads droop when they’re fully developed. However, they shouldn’t be ‘looking’ at the ground before they’ve developed fully. Straggly petals are another clue that something is off with your flower.

Always check the stem near the base as well. If the stem of your sunflower is turning brown, there’s way too much moisture in the soil. These conditions are bad for your flowers and great for promoting mold and rot.

Mold, mildew, or the presence of fungus in the soil around your sunflowers are all signs of too much moisture. You can treat it with a fungicide like neem oil, but it’s even more important to ensure the ground dries out.

The Mr. Sprout & Co. Sunflower Seed Starter Kit from Amazon has everything you need to start growing sunflowers. This made in the USA kit comes with an A to Z growers guide to help you avoid sunflower problems. Scientist-recommended pots help prevent mold. Best of all, you get peace of mind with a thirty-day money-back guarantee. Get growing fast when you click right here.

Saving Your Overwatered Sunflowers

So long as you catch it early, you can save your overwatered sunflowers easily. If you are fortunate, you can cut back on excess watering, and the sunflowers will sort themselves out. With proper sunshine and well-aerated soil, your plants can bounce back from roots that were swimming within a few days. Follow the Steps Below for more serious cases of near-drowned flowers.

  1. Stop watering at night. Evaporation is less serious once the sun goes down. People who live in the desert can seriously benefit from night watering to save on water. For everywhere else, cooler evenings mean moist and humid conditions that spawn bacteria and mold in flower beds.
  2. Treat the plant with a fungicide. Getting rid of any unpleasant growths will help the flower survive and thrive.
  3. Get potted sunflowers out of the sun. Take them to a shady area for the day and dispose of dead leaves.
  4. Stop fertilizing until the plant is healthy again. Give your sunflower roots time to heal instead of overwhelming amounts of nutrients.
  5. Finally, check for drainage and let the soil dry out. This last step is critical to plant recovery.


Should I Pull Dead Leaves Off Sunflowers

Do not pull dead leaves off of sunflowers. Firstly, those yellow leaves on your sunflower are not necessarily dead. Secondly, pulling is the wrong method.

Yanking leaves off will traumatize the plant. If you’ve determined that your sunflower leaves are indeed deceased, get a sharp pair of scissors or garden shears. Cut the leaves off cleanly at the stem.

Instead of hitting the plant further, a clean-cut is like doing surgery on your plants. However, removing dead leaves is not necessary. Leaves will mostly fall off on their own. It is best to allow nature to do its job.

I recommend a Nature’s Blossom Sunflowers Garden Kit from Amazon for any aspiring sunflower grower. Not only are these chemical-free seeds non-GMO, but they are cultivated right here in the USA as well. You’ll love the easy-to-follow step-by-step instructions. With more seeds than you need to get started and excellent germination rates, these kits make great gifts for friends and family too. Read the reviews for yourself when you click here. 


Why Are My Sunflower Leaves Curling

Your sunflower leaves are drooping and curling for the same reason they are yellowing. Especially in indoor gardens, overwatering is a big issue. Sunflower leaves may show signs of unhappiness before they change color.

Healthy leaves will naturally follow a slight downward slope. However, a serious droop is likely the result of overwatering. Since your plants have to store water somewhere, they will push too much water into the leaves.

Overwatered leaves droop and curl from the excess water. Additionally, this can interfere with proper photosynthesis. Lack of green pigment means the chlorophyll plants need is absent or running out. When you notice this, immediately cut back on watering and give your plants time to recover.

Final Thoughts

One of the nice things about raising sunflowers is that they are fairly easy to troubleshoot. If your sunflower has yellow leaves, something is almost certainly wrong at the root level. Most of the time, it results from too much water, but excess clay in the soil is also a possibility.

Sunflowers with nitrogen or phosphorous deficiency will also show the problem clearly. When your flowers have yellow leaves with green near the veins, it’s a sign they need more nutrients. In this case, feed them or amend the soil in your beds to get healthy blooms.

Unless you live in a hot and arid region, your sunflowers shouldn’t need more than an inch or so of water each week as they grow. Luckily, you can usually let the roots and stem dry out if you overwater, and these hardy plants will bounce back.

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