Can You Bury Leggy Sunflower Seedlings?

If you’ve noticed that your sunflowers are wilting and falling over, this is a sign that they’re becoming leggy. Sunflower seedlings that don’t get enough sun can become leggy as they try to stretch for the sunlight. Since this can cause them to struggle to survive, does this mean you can bury them to encourage their healthier growth?

You can bury leggy sunflower seedlings. This is important to do to help the sunflowers to grow stronger. Planting the seedlings in a sunny spot in the garden is essential to give them enough light they require. 

In this article, I’ll explore how to bury sunflower seedlings so that you give your glorious sunflowers the chance to grow and thrive. I’ll also feature extra tips to follow after you’ve planted your sunflower seedlings to set them up for healthy growth. 

How to Bury Leggy Sunflower Seedlings

If you can see that your sunflower seedlings are too tall and thin, to the point where they look like they can’t support themselves, you should plant them in new soil and give them healthier growing conditions. That’s where burying your sunflower seedlings come into play, which basically means that you’ll plant them in fresh soil

However, since sunflower seedlings have specific requirements, such as a lot of daily light, you will need to follow essential tips to bury them correctly:

Plant Sunflower Seedlings When Temperatures Are High

Since sunflowers love the warmth and are highly heat-tolerant, you should plant them when the temperature at night is higher than 60 °F (15 °C), as they don’t want to be planted when it’s cold. If local weather forecasts say that cold weather is imminent, wait until the temperatures increase before you transplant them. 

However, if it’s happened that you planted the sunflowers by mistake when the weather wasn’t warm enough, you can still encourage them to continue to grow healthy by covering them.

You can do this by covering them with a DIY plastic jug:

  1. Cut and remove the bottom of a plastic soda bottle with a sharp utility knife and throw it away so that you’re left with the top two-thirds of the bottle. 
  2. Make the plastic bottle smooth by removing any sharp edges. 
  3. On the stove, warm up a non-stick skillet. 
  4. Push the cut edge of the plastic bottle onto the skillet. You want to hold it firmly and keep it upright as you melt the rim of the plastic. You want the edges to curl to about a quarter-inch (0.635cm). 
  5. Remove the bottle from the heat. 
  6. Place it over the bottom of a glass measuring cup. This will ensure that the plastic can become firm and settle while producing a ring when the plastic cools down. While you might think you can skip the step of curling the edge of the plastic dome, you shouldn’t because when it’s hardened, it’ll be more robust. 
  7. Position the cloche over the sunflower seedling. 
  8. Avoid putting the bottle cap on the bottle during the day as this will prevent the seedlings from becoming too hot. At night, make sure you put the cap on to make the temperature warmer for your plants. This will protect your sunflower seedlings from cold temperatures. 

Check for True Leaves

When you’ve noticed your sunflowers have germinated, they will have the first set of leaves. These are small and weak. Wait for when the seedlings grow true leaves, which are smaller versions of adult leaves. When seedlings grow these leaves, it’s a sign that they’re strong enough to be transplanted into individual containers. 

Dig Holes for Your Seedlings

Pick a spot in your garden where there’s a lot of sunlight to plant your sunflower seedlings. Sunflowers require between six and eight hours of direct sunlight every day. 

Make holes for the sunflower seedlings in the soil, which you can do with a spoon. You can also use the spoon to dig out the sunflower seedlings you want to transplant from their containers. 

When digging a hole that’s large enough for your sunflower seedlings, make sure that the hole is a bit larger than the sunflower’s rootball. It should also be around the same depth. 

Be Gentle With the Seedling Stems

Sunflower seedling stems are fragile, so you need to handle them with care when burying them. If you’re worried that you’re not going to be able to handle them with care, you can use chopsticks instead of your fingers. 

If you’ve picked up multiple seedlings in one lump of soil, try to remove the thinnest ones and plant the healthiest ones instead. You can easily remove the weakest seedlings with the use of pruners. 

When you have one or two seedlings and soil, plant them in one container or tray. 

Amend the Soil 

Sunflowers need loose, well-draining soil. The soil should be filled with nutrients and organic matter. To do this, you can apply fertilizer, which should be worked about eight inches (20.32 cm) into the soil. 

When choosing the best fertilizer to give your sunflower seedlings enough nutrients, I’d recommend Miracle-Gro Shake’ n Feed All Purpose Plant Food, which is available on It contains essential nutrients for a variety of plants and will feed your sunflowers for up to three months. It’s slow-release, so it won’t burn your sensitive seedlings. 

Tamp Down the Soil

Once you’ve planted the sunflower seedlings in the ground, use your fingers to tamp down the soil around them. This will encourage the soil to settle while also ensuring that there’s contact between the soil and the roots of the plant. 

Tips for Ensuring Buried Leggy Sunflower Seedlings Survive

Since sunflowers need lots of light to grow and have other specific requirements that other flowering plants don’t need, there are some extra essential tips to follow when planting sunflower seedlings:

Plant Sunflower Seedlings Outside

Since sunflowers sometimes struggle to grow indoors, and this causes them to become leggy because of a lack of light, you want to transplant them into the garden as soon as possible.

Plant Them After the Frost

Ensure you plant the sunflower seedlings in the ground once the last frost has passed, as sunflowers are quite intolerant of the cold. However, you shouldn’t wait too long to bury them in the ground if they’re leggy, as sunflowers have a 60-day life cycle, so you want to move them from inside your home or greenhouse into the garden quickly.

Plant Leggy Seedlings in Slightly Acidic Soil

You want to ensure that the soil pH is between 6.0 and 7.5 when growing sunflowers. You can test your soil’s pH with a soil pH meter.

Space Them Apart Properly

You’ll want to space your sunflower seedlings six to 36 inches (15.24-91.44cm) apart. The space you need between sunflower seedlings will vary according to the sunflower variety you’re planting. 

Water Them Deeply After Burying Them

Once you’ve planted the sunflower seedlings, you should water them thoroughly. Strive to give them three inches (7.62cm) of water immediately after burying them. Once the plants are established, you can decrease this to approximately one inch (2.54 cm) every week.  

Apply Four Inches (10.16 cm) Of Mulch Around Them

The mulch prevents weeds from growing through the soil and competing with seedlings for nutrients, which promotes leggy seedlings. It also helps the sunflower seedlings to preserve moisture. But don’t let the mulch contact the seedlings’ stalks, as this can promote disease. 

Harden off Your Seedlings

If you’re planting seedlings into a new container indoors, you need to harden them off. This is when you help the seedlings to get used to the temperature changes. Keep the seedlings outside during the day, then bring them indoors at night so that you don’t shock them. You should do this for a week before planting them.  

Thin the Seedlings to Give Them Space to Grow

Since sunflowers have large roots that spread out into the soil, they need enough space to grow. To ensure that your sunflowers grow healthy, you should thin out the seedlings that are clumped together. Remove the thinnest and weakest seedlings.  

Protect Your Sunflowers From the Wind

Tall sunflower varieties will be damaged by strong winds, so ensure you plant them in sheltered areas of your garden. You can also use stakes to support them.

Learning how to grow sunflowers can be tricky. They may have growth requirements that make them different from other flowers. Be sure to read my blog post covering their requirements to grow healthy sunflowers: How to Grow Sunflowers (Outdoor and Indoor Guide)

Final Thoughts 

Sunflower seedlings grow quickly, so you have to ensure that you bury them in the garden as soon as they become leggy. This encourages them to grow healthy.

There are essential tips you should follow when burying sunflower seedlings, such as: 

  • Planting them in a bright, sunny area
  • Giving them slightly acidic soil
  • Digging holes for the seedlings that are as large as their rootballs
  • Placing mulch around them to preserve moisture
  • Adding fertilizer to the soil to give the seedlings nutrients

Alexander Picot

Alexander Picot is the founder of and its lead content writer. He created the website in 2022 as a resource for horticulture lovers and beginners alike, compiling all the gardening tips he discovered over the years. Alex has a passion for caring for plants, turning backyards into feel-good places, and sharing his knowledge with the rest of the world.

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