How to Grow Great Sunflowers In Your Garden

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yellow sunflowers with text overlay

Whether you are a beginner gardener or an experienced gardener, sunflowers are a wonderful addition to any garden. Since they are pest-resistant heat-tolerant, and sunflowers are a favorite of gardeners everywhere. These plants are fast-growing, and these cheery flowers are a top choice for almost anyone looking to add a new flower to their garden. Here you will learn how to grow them in your garden and everything you need to know, from choosing the right variety to protecting them from pests. It’s surprisingly easy and fun to watch sunflowers blossom and bring beauty to your garden. Let’s take a look at the best methods for growing sunflowers!

Key Characteristics of Sunflowers?

Sunflowers are one flower that has some key characteristics to understand before planting in your garden. Here are things to know before you get started:

  • Sunflowers are Allelopathic:
    This means they align in a group of plants that release specific toxins in the soil through their seeds, roots, or stems that can potentially hinder other plants’ growth. Pairing with other plants that are allelopathic will mean they both hinder each other and lead to power growth on account of both. 
  • They are Tall!
    Sunflowers can grow anywhere from 3 feet to over 10 feet tall, depending on the variety. They are the best place somewhere that you want to create a wind barrier. 
  • Growth Habits:
    These towering plants grow extremely quickly! In just a few months, they can grow dramatically fast and do all this growth in one year since they are annuals. 
  • They follow the sun:
    Sunflowers are one of many plants that are heliotropic, which means they follow the sun. It is a magical thing to watch them find the sun throughout the day. This increases their ability to grow quickly. 
  • They grow in a variety of Growing Zones:
    They can grow in zones 2 to 11. It all depends on the timing of planting to grow them in these various places. 
  • Pollinators:
    This plant feeds pollinators of all kinds, from birds to butterflies to bees. They also will bring beneficial bugs to your garden. Leaving the heads will create a natural bird feeder to enjoy at the end of the season. 
  • Sunflowers are native to North America:
    Over 4,500 years ago, Native Americans cultivated them to grow in our gardens the way we grow them now. They used the wildly growing variety to create the sunflowers we know now. 

white light sunflowers growing together

What Sunflower Variety to Choose?

There are two main varieties of sunflowers to choose from. Just like tomatoes, the plant can be divided into two groups. For sunflowers, the two areas the plants land relate to the number of times they bloom:

  • Branching:
    This means the plants will create multiple flower heads in their growing season. They won’t be as large in many cases, but you will get continual blooms. These are my personal favorite!
  • Single-stem:
    This variety will only create one blossom. Though many gorgeous varieties land in this category, it does mean they will only bloom once before their heads begin to sink. Typically, the bloom lasts 2-3 weeks before it begins to fade. 

Beyond this, it is about looking at aesthetically beautiful ones for you. I personally love White Light, Teddy Bear, and Autumn Beauty.

woman in yellow standing in garden with sunflowers

How Long Do Sunflowers Take to Grow?

In most cases, it takes about 80-120 days for full maturity of your sunflowers. It is important to understand the length so you can estimate with your first and last frost when to seed your sunflowers directly in the soil. 

How to Plant Sunflowers

Growing sunflowers is very easy, but there are key things you need to know so you can choose the right spot for them. Below you will find everything you need to know to plant and grow sunflowers this year:

  • Choose the right location:
    Your sunflowers should be in a sunny spot where they get 6-10 hours of sunlight a day. The soil will need to be loose and well-draining, and fertile. 
  • Soil Preparation: 
    Clear the garden area of any weeds. Add 2-3 inches of rich compost to ensure well-balanced and fertile soil. Sunflowers like a slightly acidic to neutral pH in their soil, which most gardens lean towards. 
  • Plant Seeds:
    Seeds for your sunflowers can be planted right at or after your last frost date. See your growing zone chart to get that exact info. Push the seeds 1 inch (double the size of the seed is my secret) deep into the soil and place them every 6-12 inches, depending on the variety and seed packet recommendation. 
  • Water the seeds:
    To encourage germination, water them consistently to keep the soil moist for 7-10 days till they germinate. The sunflowers will sprout in less than 2 weeks if they are watered and planted at the right time. 
  • Protect the seedlings:
    Once they sprout, they are wonderful yummy food for mice, birds, rabbits, and squirrels. So make sure you protect them with a row cover till they are about 1 foot tall if you have these pests in your garden. Once their tough stems appear, they are less likely to get eaten. 
  • Fertilize: 
    Since sunflowers are heavy feeders, you will want to fertilize them with an all-purpose fertilizer like Neptune’s Organic Fish and Seaweed fertilizer every 3-4 weeks. 
  • Continued Care: 
    Once they grow above a foot, it is about making sure, like the rest of your garden, it gets 1-1.5 inches of water a week. Other than that, you will wait for them to bloom for you. 

With these simple things, you will have gorgeous and abundant sunflowers your entire summer and fall in your garden!

A variety of sunflowers growing together in a row

Pest and Disease Protection for Sunflowers

Treating the common pest and disease issues isn’t hard, but here is what to look for and how to treat them:

  • Choose Disease-Resistant Varieties:
    Not all varieties are created equal in terms of being resistant to disease. If you have issues with downy mildew and more, then considering a more resistant variety may be a great choice. 
  • Choose Companion Planting:
    We offer an entire course on how to use companion planting in your garden, but you can place nasturtium and marigolds around your sunflowers to keep out mice, squirrels, and more. Strong-smelling plants and herbs will keep away bunnies and mice. 
  • Practice rotation:
    If you had a disease before, such as downy or powdery mildew, you will want to shift the location of your sunflowers for a year. 
  • Water at the roots:
    Watering at the roots of the plant will lower disease. Though Downy Mildew exists in the air, having damp leaves creates more potential for it to grab the broad leaves of the sunflower. 
  • Spraying for Mildew: 
    I don’t suggest doing any spraying in your garden at all. But there are places you can find more natural ways of preventing it. If the mildew is present, I will observe and remove the leaves as I see them develop issues. I then dispose of them by burning them in a bon fire. The sooner they are removed, the better. Both because the plant can generate new, more productive leaves, you aren’t hurting the ecosystem or soil, and it is less likely to spread. 

By following these tips, you can help prevent pests and diseases in your sunflowers and keep them healthy and beautiful all season long.

bouquet of white light sunflowers with purple flowers at sunset held by a woman in a chambray shirt

What Should I Do with Sunflowers?

  • Save Seeds:
    Keeping seeds whether for you to snack on or for your garden next year, is very simple. The sunflower has a cover over the seeds that will dry. Pull a few heads before they fully dry out; once the seeds are present, the birds will want them. You can cover the heads with mesh bags to present the birds, but it is just as easy to pull them to dry naturally in your greenhouse or home. Once the pollen cover parts will easily push off, the seed is underneath. You can then remove the seed and roast it or save it for growing sunflowers the next year. 
  • Leave them for Birds:
    I usually save a few seeds for us to grow sunflowers the next year. Since they are open-pollinated, it is fun to see what varieties mix together and are created, but I leave the others for the birds. The reason is sunflowers are native and feed the birds well before they migrate to warmer places or prep for winter. Feeding our birds is really important. Instead of buying processed sunflower seeds for them, I let them enjoy our sunflowers that grew without pesticides or anything harmful to them. They typically spread seeds on the ground that sprouts into new plants the next year, meaning less work for me. 
  • Cut Bouquets:
    It is so fun to cut our branching variety to add to our bouquets every summer. They don’t make very good dried flowers and can be heavy on pollen deposits, but they sure are beautiful!

dried sunflower heads with seeds coming out on a white table

Growing sunflowers is a rewarding experience; with the right know-how, your garden can burst with color! Follow these methods to get the best sunflowers and watch your garden transform.

Learn more about how to grow a garden this year through our Beginner Gardener Course and become part of an avid group of gardeners. 

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