How to Grow Sunflowers

Analysis by Dr. Joseph Mercola Fact Checked

how to grow sunflowers

Story at-a-glance

  • The bright yellow face of the sunflower plant is more than ornamental; prepare your soil with organic compost, plant the sunflower seeds after the last frost and be prepared to harvest sunflower seeds in the fall
  • Sunflowers are hardy drought resistant plants; however, you’ll enjoy a greater harvest when you supply them with at least 2 inches of water each week, adjusting for your local weather
  • Although pest resistant, sunflower seeds are favorites of squirrels and birds; consider using chicken wire or netting to protect your plants
  • Harvest sunflower seeds in the fall as the seeds are turning brown; dry thoroughly before storing in an airtight container. The seeds are rich in vitamins E and B1 as well as selenium, magnesium, copper and manganese

WARNING!

This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

Nothing says summer quite like the bright yellow faces of sunflower plants. Growing sunflowers is easy as they are heat tolerant, resistant to pests and are remarkably tough. Seeds can be harvested in the fall and are a great snack with an irresistible flavor and satisfying crunch.

They're excellent for appetizers, salads, desserts and other dishes. If you choose not to harvest sunflower seeds, the birds in your yard will love you! It doesn't take long to discover how growing sunflowers will perk up your garden, your dinner plate and your health. Although admired as an ornamental, sunflowers actually have an amazing variety of uses.

Choose Your Sunflower Variety and Plant in Full Sun

Consider planting sunflower seeds indoors before the last frost to get a head start on the growing season. However, the plants have long tap roots, so if you do start indoors, be sure you can plant outside by the time the seedlings have two leaves. This helps to ensure you don't damage the tap root.

Planting sunflower seeds indoors will mean the young plants need to harden before being transplanted outdoors. Put them out during the day to allow the weather to thicken the stems, but return them indoors overnight. The plants may need up to two weeks to harden before being transplanted into the ground.1

Planting sunflowers seeds in direct sunlight, or an area of your garden getting six to eight hours of sun per day, is best for the health of your plants. Choosing the right spot may be one of the most challenging parts of growing sunflowers as the plants are heliotropes and follow the sun's path across the sky.2

Interestingly, this movement is triggered by the plants internal hormones in much the same way your circadian clock is ruled by hormones. There are several varieties of sunflower plants. The taller types can cast a long shadow in your garden, so plant these on the north side of your garden plot, unless you want to supply shade for other plants.

The American Giant and a couple other varieties will grow as tall as 15 feet with flower heads spanning 1 foot across.3 However, if you don't have a large space, you still have the opportunity to plant sunflowers, since dwarf varieties will measure only 1 or 2 feet tall.4 Medium height sunflower plants will stand between 5 and 8 feet with heads up to 10 inches across.

Some varieties produce a single large flower, while others will form several heads. Not all sunflowers have yellow flowers. Little Becka and Terracotta have red tinged flowers and Ms. Mars and Chianti grow in shades of purple.5 In other words, you have several choices to make before you begin growing your sunflower seeds.

Sunflower Plants Have Soil and Water Preferences

Although hardy and easy to grow, sunflower plants have soil and water preferences to support their growth and provide you with a strong harvest. If you've chosen a low-growing variety, give them plenty of room as they branch out. Plant your seeds no more than 1 inch deep and 6 inches apart when planting outdoors, and transplant your strongest seedlings between 6 and 8 inches apart.

A light application of organic compost mixed into the soil at the time of planting will encourage strong roots and protect young tender plants from blowing over in the wind. Add mulch as the plants reach 6 inches to minimize weed growth and conserve water. While drought resistant, you'll have a greater sunflower seed harvest if the plants receive sufficient water.6

Consider planting sunflower seeds staggered over five to six weeks so you'll continue to enjoy blooms through the summer and get a strong harvest in the fall. Don't over fertilize the plants as they are not heavy feeders.7 Over fertilization may cause weaker stems to break once the tops get heavy with seeds.8

Once the plants are established, water thoroughly but infrequently to encourage deep rooting. As the plants grow taller, water once a week with several gallons of water unless the weather is exceptionally wet or dry and then adjust as needed. Taller plants may need bamboo supports that must be buried deep in the soil to provide enough support in windy conditions.9

Birds and Squirrels Are the Most Consistent Pests

As much as you enjoy harvesting sunflower seeds, so do squirrels and birds. If you plan to harvest the seeds for yourself, you'll want to deter these critters with barrier devices. Deer can be kept at bay with a tall wire barrier. Birds may be scared away by positioning shiny ribbon or surveyor's tape to blow in the winds on posts around your garden. Move these every few days as the birds get used to their position.

Consider using barriers if you have birds10 that enjoy nibbling on your sunflowers. Chicken wire on posts over your flowers and netting down the side can help deter them. By using chicken wire over the top, you will continue to get insect activity and pollination for seed development in the fall. Netting down the side will keep the birds from going under the chicken wire.

You can also consider going high-tech and purchasing a sophisticated microchipped screech owl that spins in the wind and emits the sound of an attacking hawk. Although cute, squirrels have a fondness for fresh fruits, vegetables and flowers. Their foraging can happen anytime of the year but they're especially active in autumn.

Pick up any nuts, berries or acorns from the trees in your yard as this attracts the squirrels. Be sure you have tight-fitting trash cans and never leave food sitting out as squirrels are foraging animals.11 There are natural repellents, many made with the urine of the squirrels' natural predators, that can be sprayed around the garden to keep squirrels away.

When your sunflowers are ready to bloom, consider sprinkling them with cayenne pepper, which the birds don't mind but the squirrels won't eat. If you're using chicken wire and netting to keep birds out, ensure the bottom of the netting is staked to the ground and it will also help to deter squirrels.

Harvesting Sunflower Seeds and Storing for the Winter

Harvesting sunflower seeds is a fun activity for your family. If you wait too long the seeds will be too dry to roast or your local critters will have harvested the majority for you, leaving you nothing to enjoy in the fall and winter.12 As the plants are ready to harvest, the heads will begin to droop and the seeds will start turning brown.13

There are two methods for harvesting the seeds. The first is to harvest sunflower seeds when they are fully ripened on the stem and beginning to loosen from the head. Cut the stem about 1 inch below the head and briskly rub the seeds with your hand. Allow the seeds to dry before storing in an airtight container.14

You may also begin harvesting sunflower seeds when two-thirds of the seeds are mature. In this case, cut a longer piece of the stem and wrap a paper bag around the head. Hang it in a well-ventilated area for a few weeks making sure the area is dry and warm but not hot.

Once harvested, sunflower seeds can be used immediately or saved for the next planting season. Dry the seeds completely before storing and keep them in an sealed, airtight container. Most sunflower seeds will store well for up to a year when kept in the refrigerator or freezer.

Health Benefits of Sunflower Seeds

A handful of sunflower seeds equaling one-fourth cup has a mere 204 calories with a low glycemic index. One serving has nearly 82 percent of the daily recommended intake of vitamin E, 70 percent of copper and high levels of vitamin B1, selenium, phosphorus, magnesium and manganese.15

Not only tasty, the health benefits of sunflower seeds include anti-inflammatory effects benefiting your cardiovascular health. The phytosterols found in sunflower seeds help balance your cholesterol, may help reduce the severity of asthma, lower blood pressure and prevent migraine headaches,16 while magnesium is a necessary nutrient for healthy bones and energy production and helps regulate nerve and muscle tone.

Sunflower seeds are a healthy source of selenium, an important mineral in the removal of waste from the body. The seeds are also high in fiber, which may help add bulk to your stool, slow glucose absorption and keep you feeling full longer.17

Benefits of Sunflower Seeds in Your Snacks and Cooking

As a snack, it's easy to grab a handful of sunflower seeds and go. Consider adding them to your homemade trail mix, sprinkle them over your salad or grind your dried sunflower seeds to dust your meat in lieu of flour. Sunflower seeds are a fine addition to cold or hot homemade cereals and add a unique texture and flavor to scrambled eggs.18

You can also make your own nut butter at home from raw, organic nuts and seeds brimming with healthy fats and nutrients. See the recipe for nut butter using sunflower seeds in my previous article, "Crunchy and Creamy Homemade Nut Butter Recipe."

Top

By continuing to browse our site you agree to our use of cookies, revised Privacy Policy and Terms of Service.