How to Grow Sunflowers from Seed This Season

Are you thinking of growing sunflowers from seed in your garden this season? Sunflowers are one of the easiest flowers to grow from seed, no matter your hardiness zone. In this article, gardening expert Jill Drago shares all the very simple steps you'll need to follow when growing sunflowers from seed this season!

Written by Jill Drago Last updated: October 19, 2023 | 5 min read

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Growing sunflower plants from seed is quite easy and assuredly leads to the popularity of these beauties among home gardeners. These low-maintenance annual flowers are tough plants that are not too picky about the soil they grow in, and they love the full sun.

Sunflower seeds are easy to find at your local garden centers or through online retailers. You can also harvest your own sunflower seeds! Don’t forget to save some of those seeds for snacking in the fall.

Whether this is your first-time planting sunflower seeds, or you are a sunflower growing veteran, this guide will outline the process for you in a few simple steps.

First, Seed Selection

Close-up of a man's hand holding a handful of sunflower seeds against the backdrop of a blooming sunflower field. Seeds are drop-shaped, covered with a hard black shell. The sunflower plant has tall stems covered with large broad green heart-shaped leaves with serrated edges and large flower heads consisting of a large orange-brown central inflorescence of many tubular flowers surrounded by elongated, petal-like rays of bright yellow-orange. — An important step before planting sunflower seeds is choosing the right variety for you.

Early in the new year, you will typically begin to see seeds popping up at garden centers and even grocery stores and florists. The first thing you need to do is pick out the perfect variety for your yard. You may be planning on growing your sunflowers in your garden beds, or perhaps in a container.

There are many different kinds of sunflowers. Standard-sized, giant sunflowers and dwarf sunflower varieties are available in shades of yellow ranging from light yellow to a rich golden yellow. Many dwarf and mid-size sunflowers range in shades of yellow as well as pinks and deep reds.

There are single sunflowers as well as the adorable teddy bear double sunflowers. There are also different forms of sunflowers. They could be branching, or they could be single stemmed.

Before you purchase your seeds make sure you have enough room for these sunflowers to grow to their maximum height and width. Also, make sure that the area in your garden where you will eventually plant your seedlings gets enough sunlight. Sunflowers grow best in full sun conditions.

‘Sunny Bunch’ is a petite sunflower growing from 2-3 feet tall. The petals are bright yellow with brown center discs. This is a branched variety of sunflowers that will have many 7-inch flowers.

‘Goldy Honey Bear’ is a double sunflower with golden yellow petals and a small green to brown center disc. This sunflower will grow from 5-6 feet tall and will have many 7-inch flowers.

‘Kong’ is a giant sunflower reaching heights of 12-14 feet! Despite its height, this is a branching sunflower that will be made up of multiple strong and sturdy branches that support 10-inch golden yellow flowers.

Indoor Sowing

Indoor sowing is one of the most popular methods for starting seeds in the spring. You start the growing process indoors under grow lights, or in an area of your home that gets enough sunlight.

After the seedlings have begun to grow and your first frost date has passed, you then transplant your sunflowers into the garden. Let’s look at the steps you’ll follow for sowing indoors.

Step1: Gather Tools and Materials

A woman launches seeds indoors in early spring. Close-up of a woman's hands in beige floral print gloves holding a handful of starter potting soil over a container full of soil. In her other hand, there are several packets of seeds. On the table there is a black plastic tray with square cells and a garden shovel. — To plant sunflower seeds, you need seeds, trays, soil, and water.

Before you get started, it is always a great idea to get all of your tools and materials organized. This will help to make your seed-sowing process as seamless as possible.

Tools and Materials to Have on Hand

Sunflower seeds
Seed trays or pots
Seed starting mixture
A watering can, and/ or a spray bottle
Plastic wrap or tray covers
Grow lights
Heating mat

Step 2: Prepare Your Materials

A gardener fills a plastic tray with soil using a trowel. Gardener's hand in an orange glove. The starter tray has deep square cells filled with loose, compacted soil. The trowel is black with a bright yellow handle. — Fill trays with seed-starting mixture and moisten with a spray bottle.

Before you begin planting your seeds, lay out your seed trays or pots and fill them with the seed-starting mixture you have chosen. Moisten the soil a bit with your spray bottle or watering can.

This is also a great time to set up any extra equipment you are using such as a heating mat or grow light.

Step 3: Plant Your Seeds

Close-up of female hands planting sunflower seeds in seed germination starter trays filled with soil. Seeds are drop-shaped, covered with a black shell. — It is recommended to press sunflower seeds ½ inch into the soil.

Once you have everything all setup, you can begin to plant your sunflower seeds! Indoor sowing of sunflower seeds should take place about 4 weeks before your last frost date. Push your sunflower seeds about ½ inch down, into the soil.

If you are using pots rather than a tray plant 3 seeds in one pot. This will help ensure that you have at least one strong and successful seedling per pot. Cover lightly with soil, and water. Place your trays under your grow light or in a sunny window that gets direct sunlight.

As the seedlings grow you will be able to thin out your pots. If you have multiple seedlings per pot take a hard look at each pot and decide which seedling looks the best.

You will want to wait until the seedlings have a few sets of leaves each. Gently pull the seedlings out that you don’t want anymore. Take extra care not to disturb the roots of the other sunflowers.

Step 4: Hardening Off

Close-up of sunflower sprouts in black plastic trays, outdoors. Sunflower sprouts have small, slender, pale green stems with a pair of smooth, oval leaves topped with a black seed shell. — Be sure to harden off seedlings before planting them in the garden.

Once you have a bunch of healthy sunflower seeds it is important to harden off your seedlings before you plant them in the ground.

To do this, you will want to wait until your temperatures reach about 50 degrees. Bring your trays or pots outside to a sunny location. Bring them indoors at night.

This process will allow the seedlings to get accustomed to the wind and sun in your yard and will set you up for success in the summer.

Step 5: Planting Seedlings

Close-up of male hands transplanting sunflower seedlings into the ground in the garden. There is a garden shovel and seedlings with bare roots on the ground. Sunflower seedlings have long, pale green stems and several green, oval, hairy leaves. — Carefully remove the seedlings from the container and plant them in a hole about the same size as the container.

Now that you are ready to transplant your seedlings into your garden all you will need is a garden trowel and a water source.

Sunflower roots do not like to be disturbed so you need to be very careful while you are popping your seedlings out of whatever type of container they are growing in.

Dig your hole about the same size as the container your seedlings have been growing and pop the seedling right into the hole! Backfill with your garden soil and water. That’s it, it could not be more simple. Now all you need to do is sit back, relax, and enjoy the flowers.

Direct Sowing

Close-up of a gray-gloved gardener's hand planting sunflower seeds directly into the ground in a sunny garden. Nearby is a clear plastic container full of seeds. Seeds are drop-shaped, covered with black shell. — You can plant sunflower seeds directly into the ground in early May, once the threat of frost has passed.

Once you are out of the threat of frost, usually late April or Early May, you can go ahead and plant your sunflower seeds directly in the ground. Before sowing the seeds, clean your garden beds and work some organic matter into the top few inches of the soil.

This is a great time to add some compost to your soil. The nutrients found in your compost will give your seeds a natural form of fertilizer and help them to grow strong from the start.

Sunflower seeds should be planted at least ½ inch down into the ground and covered with garden soil. Plant seeds in groups of 3 to ensure you will have successful plants. Allow for about 2 feet of space between groups.

Every sunflower will have different heights and spacing instructions, be sure to check the seed packed to make sure you are not overcrowding your plants. Firm the soil once your seeds have been planted and keep your soil evenly moist.

In about a week you will begin to notice your seedlings emerging from the ground. Keep your eye on these seedlings. Once they have two sets of leaves it is time to begin thinning your plants. Thinning is simply removing 2 of the 3 seedlings and allowing the strongest seedling to stay in place. Continue to water your sunflower babies.

Maintenance and Care

Close-up of a gardener in denim overalls watering blooming sunflowers from a red watering can in a sunny garden. The sunflower has a large flower head consisting of many tubular orange-brown flowers in a central disk surrounded by orange petal rays. The leaves are large, dark green, heart-shaped, hairy. — Sunflowers need to be watered once or twice a week.

As your sunflowers grow taller you may need to give them support until they are strong enough to support themselves. Simply use a garden stake and some garden twine and gently tie the 2 together in a few spots to make sure the plant grows straight and sturdy.

Sunflowers do not need much water once they get growing. Water them once or twice a week. Oftentimes rainfall will be enough to sustain these sunny flowers.

Harvesting

A female gardener in a striped apron collects orange sunflowers in a summer garden with a pruner. In her hands she holds a small bouquet of red and orange sunflowers. Sunflowers have beautiful medium flower heads with bright red and orange petals surrounding dark brown centers. — Cut sunflowers can last for several weeks in a vase.

Many people love to add sunflowers to their cutting gardens. They are easy to cut, and they can last for a few weeks in a vase. When you are ready to snip your blossoms, simply take a clean set of garden shears and cut just above a set of leaves. Make sure you have more than enough length of stem to fit your vase properly!

If you would rather not snip the flowers from your plants, you can leave the flowers on the plant and harvest their sunflower seeds instead! Leave the flowers on the stems until the petals are brown and you can tell that the flower has died.

You will also notice that the seeds have become plumper, and they may wiggle easily when touched. Many sunflower seeds are edible, but all can be planted in the next season to grow more sunflowers.

Final Thoughts

Growing sunflowers from seed is a fun and rewarding way to add bright color to your gardens. This is also a great task to do with kids because the seeds are large and easy for them to handle. Another benefit to growing your own sunflowers is that you get to choose from the many different varieties of sunflowers, making it easy to customize your garden.

How to Grow Sunflowers from Seed This Season

First, Seed Selection

‘Sunny Bunch’

‘Goldy Honey Bear’

‘Kong’