Growing sunflowers in New Hampshire is an incredibly rewarding experience. Sunflowers are full of beauty, color, and life, and they can bring vibrancy to a garden that is hard to find anywhere else.
Sunflowers are also easy to grow and require minimal maintenance, which makes them a great choice for those who are new to gardening or those who want to add some life to their outdoor space. With the right care, sunflowers can easily thrive in New Hampshire’s climate, allowing them to put on a stunning show of color and beauty.
New Hampshire’s climate and growing zones
New Hampshire is a Northeastern state with a continental climate. It experiences four distinct seasons, with cold winters, warm and humid summers, and a variety of precipitation throughout the year.
Growing zones 3 through 6 in New Hampshire are generally characterized by cold winters and warm summers. The average annual temperature in zone 3 is between -20 and -10°F (-29 to -23°C), whereas zone 6 experiences temperatures between 0 and 10°F (-17 to -12°C). These temperatures are suitable for a range of hardy plants and vegetables to be grown, including many varieties of trees, shrubs, and flowers.
The growing season in New Hampshire is relatively short compared to other states in the region. Typically, the last spring frost occurs in May and the first fall frost takes place in early October. The length of the growing season is dependent on elevation and location, with the warmer coastal areas having a longer growing season.
The average annual precipitation in New Hampshire ranges from 40 to 50 inches (101 to 127 cm). This is evenly distributed throughout the year, with the most precipitation occurring during the winter months. Areas along the coast tend to experience more rainfall, while the interior receives more snow.
Growing sunflowers in New Hampshire
Growing sunflowers in New Hampshire can be both rewarding and challenging due to the climate. Sunflowers prefer full sun and warm temperatures, which can be hard to come by in the Granite State. In the summer, New Hampshire can get hot and humid, but temperatures can also dip below freezing in the winter. Sunflowers may not survive a cold winter, so they may need to be protected with a layer of mulch or a cold frame.
In addition to the cold climate, New Hampshire has a short growing season. The last frost date is typically in early June and the first frost date is typically in mid-September. This leaves a relatively short window of time for sunflower growth and bloom. Additionally, sunflowers require a lot of water, which can be hard to come by in New Hampshire. The soil can be dry and sandy, so gardeners may need to supplement with a drip irrigation system or frequent deep watering.
Despite the challenges, growing sunflowers in New Hampshire can be a rewarding experience. For those who can provide the right environment, sunflowers will grow tall and strong, and their large and vibrant blooms will bring life to your garden. Sunflowers are also beneficial to the local ecosystem, providing food and shelter for birds and other wildlife. With a little extra effort, gardeners in New Hampshire can enjoy the beauty of sunflowers in their gardens.
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 New Hampshire
Sunflower seeds should be started indoors 4 weeks before your final frost date. In New Hampshire, the final frost dates are:
- Zone 3: Around May 15th
- Zone 4: Around May 12th
- Zone 5: Around April 30th
- Zone 6: Around April 21st
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
- Zone 5: Around April 1st
- Zone 6: Around March 24th
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 New Hampshire
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 New Hampshire
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!