Growing sunflowers in Minnesota can be a great experience. Not only do these vibrant, cheery flowers bring life to any outdoor space, but they are also quite hardy and easy to grow. With proper care, sunflowers can thrive in the cold weather of Minnesota.
They can also be a great source of food for birds and other wildlife. With their bright yellow petals and towering stalks, sunflowers are sure to make your garden a unique and lively oasis.
Minnesota’s climate and growing zones
Minnesota has a humid continental climate, with cold winters and warm, humid summers. Growing zones 3 and 4 in Minnesota experience a wide range of temperatures throughout the year, with average lows in the winter reaching into the single digits and average highs in the summer reaching into the 80s.
Zone 3 is located in northern Minnesota and is generally colder than Zone 4. The average minimum temperature in Zone 3 ranges from -30°F to -20°F, while the average maximum temperature in Zone 3 ranges from 40°F to 50°F. The growing season in Zone 3 typically begins in late April and ends in late September.
Zone 4 is located in the southern half of Minnesota and is slightly warmer than Zone 3, with average minimum temperatures ranging from -15°F to -5°F and average maximum temperatures ranging from 50°F to 60°F. The growing season in Zone 4 typically begins in late March and ends in late October.
Both growing zones 3 and 4 in Minnesota experience a wide range of precipitation, with average annual totals ranging from 20 to 30 inches per year. Snowfall is also common in both zones, with the average annual snowfall ranging from 30 to 50 inches.
Growing sunflowers in Minnesota
Growing sunflowers in Minnesota can be a challenging endeavor due to the cold climate. Sunflowers are a warm-weather crop and do not fare well in the cold temperatures typical of Minnesota. The cold can damage or kill the plants and the short growing season can make it difficult for them to reach maturity before the cold weather sets in.
For those who wish to attempt to grow sunflowers in Minnesota, it is important to keep in mind the cold climate and plan accordingly. Planting sunflower seeds in the spring allows them to take advantage of the warmer weather and longer days and gives them the best chance of reaching maturity before the cold sets in. Starting the seeds indoors can also give them a head start in the growing season, and allow them to be transplanted outdoors once the weather has warmed up.
For those who live in warmer climates, growing sunflowers is much easier. The longer growing season and warmer temperatures make it easier for sunflowers to reach maturity, and they will usually produce bigger and better blooms. Sunflowers grown in warm climates are usually more abundant, and they can also be planted earlier in the season for an even greater harvest.
Some of my favorite varieties of sunflower include:
- Mammoth Grey Stripe Sunflower (Helianthus annuus) – 75-100 days to maturity
- Teddy Bear Sunflower (Helianthus annuus) – 60-90 days to maturity
- Red Sun (Helianthus annuus) – 65-95 days to maturity
- Autumn Beauty Sunflower (Helianthus annuus) – 75-90 days to maturity
- Lemon Queen Sunflower (Helianthus annuus) – 75-95 days to maturity
- Velvet Queen Sunflower (Helianthus annuus) – 90-110 days to maturity
- Dwarf Sunspot Sunflower (Helianthus annuus) – 60-90 days to maturity
- Giant Sungold Sunflower (Helianthus annuus) – 85-110 days to maturity
- Evening Sun Sunflower (Helianthus annuus) – 75-95 days to maturity
- Sundance Kid Sunflower (Helianthus annuus) – 75-95 days to maturity
When to start sunflowers indoors in Minnesota
Sunflower seeds should be started indoors 4 weeks before your final frost date. In Minnesota, the final frost dates are:
- Zone 3: Around May 15th
- Zone 4: Around May 12th
You should also consider the size of the variety of sunflower you are planting, as shorter varieties can be planted later and taller varieties will need to be started a week or two earlier. Sunflowers should be started indoors:
- Zone 3: Around April 17th
- Zone 4: Around April 14th
Starting sunflowers from seed is a relatively easy process that can be done both indoors and outdoors. To begin, you will need to purchase sunflower seeds from a garden center or online. When selecting seeds, make sure to look for the desired variety you want to grow. Once you have your seeds, you can choose to start them indoors 4 weeks before the last frost date for your region.
Fill a seed tray with starter soil and moisten it with a spray bottle. Place your seeds on top of the soil, cover them lightly with starter soil, and water them gently. Place the tray in a warm and sunny spot, and keep the soil moist. Once your plants have grown 2-3 sets of leaves, you can transplant them outdoors.
Planting sunflowers outside in Minnesota
Sunflower seeds should be planted outdoors after the last average frost date for your area. Planting sunflower seeds too early can result in poor germination and seedling growth and potentially death if there’s a hard freeze.
When planting outdoors, make sure the area has plenty of sunshine and well-draining soil. Dig a hole that is twice the size of the root ball, and fill the hole with compost or aged manure. Place the seedling in the hole and backfill with soil, then water deeply.
For the remainder of the sunflower’s life, make sure to keep the soil moist and fertilize regularly. With proper care, you should have beautiful sunflowers in no time!
When to harvest sunflower seeds in Minnesota
When sunflower seeds are ready to be harvested, the back of the flower head will be dry and start to turn brown. The individual seeds will be dry and firm. The green husks surrounding the seeds will have turned yellow or white and begun to dry out. To check if the seeds are ready to be harvested, lightly pinch the seed head between your thumb and forefinger. If the husks break open easily, the seeds are ready to harvest.
Harvesting sunflower seeds is easy. Cut the flower head off the stem and spread it out on a clean surface. To remove the seeds, use your hands to rub the flower head and release the seeds. Collect the seeds in a large bowl or container. Once the seeds are harvested, store them in an airtight container in a cool, dry place. Make sure the container is well sealed to keep the seeds from going bad. Sunflower seeds can last for up to a year if stored properly.
Sunflower seeds are delicious and nutritious snack food. They can be eaten raw, toasted, or sprouted. Sunflower seeds are also used in salads, cereals, granola, and energy bars. They are loaded with essential vitamins and minerals like Vitamin E, phosphorus, magnesium, and zinc. Sunflower seeds can also be used to make sunflower seed butter, which is a great alternative to peanut butter.
In addition to being a healthy snack, sunflower seeds are also used to make birdseed. You can leave your sunflowers intact outside well after the flowers have died to give your local birds a tasty snack!