Growing sunflowers in Hawaii is an incredibly rewarding experience. The warm, tropical climate and abundance of sunshine make Hawaii an ideal place to cultivate beautiful sunflower gardens. The flowers are incredibly hardy and can thrive in humid, tropical environments. With a little care and attention, you can be rewarded with stunning blooms that will last for months.
Not only are sunflowers a beautiful addition to any garden, but they are also a great source of food and are perfect for attracting pollinators to your garden. Growing sunflowers in Hawaii is a great way to bring vibrant, cheerful color to your landscape and to enjoy the many benefits of growing these majestic flowers.
Hawaii’s climate and growing zones
Zone 9a is located at an elevation of 0 to 100 feet and has a tropical rainforest climate. The temperatures remain relatively consistent year-round, with an average high of 84°F and an average low of 68°F. Rainfall is abundant and frequent, with an average of 200 days of precipitation per year. This climate is ideal for growing tropical fruits and plants, such as banana, papaya, and mango trees.
Zone 10a is located at an elevation of 100 to 500 feet and has a warm, humid climate. The temperatures remain relatively consistent year-round, with an average high of 91°F and an average low of 71°F. Rainfall is abundant and frequent, with an average of 175 days of precipitation per year. This climate is ideal for growing a variety of vegetables, such as tomatoes, peppers, and squash.
Growing Zones 11a through 13a
Zone 11a is located at an elevation of 500 to 1,000 feet and has a subtropical climate. The temperatures are cooler than in lower elevations, with an average high of 83°F and an average low of 67°F. Rainfall is still abundant and frequent, with an average of 150 days of precipitation per year. This climate is ideal for growing a variety of fruits, such as avocados, guavas, and lychees.
Zone 12a is located at an elevation of 1,000 to 2,000 feet and has a temperate climate. The temperatures are cooler than in lower elevations, with an average high of 77°F and an average low of 61°F. Rainfall is still abundant and frequent, with an average of 120 days of precipitation per year. This climate is ideal for growing a variety of flowers and ornamental plants, as well as many cool-weather vegetables, such as broccoli and cauliflower.
Zone 13a is located at an elevation of 2,000 to 3,000 feet and has a temperate climate. The temperatures are cooler than in lower elevations, with an average high of 73°F and an average low of 57°F. Rainfall is still abundant and frequent, with an average of 90 days of precipitation per year. This climate is ideal for growing a variety of flowers and ornamental plants, as well as many cool-weather vegetables, such as cabbage and kale.
Growing sunflowers in Hawaii
Growing sunflowers in Hawaii is a great way to enjoy the beauty of these iconic flowers in a warm climate. In Hawaii, sunflowers can be planted throughout the year and they will usually bloom in the summer months. Sunflowers thrive in warm and sunny climates, so Hawaii is an ideal place for them. The long days of sunshine and mild temperatures make it a perfect environment for sunflowers to grow and bloom.
However, there are a few challenges to growing sunflowers in Hawaii. The main challenge is the heavy rains that occur during the summer months. Heavy rains can cause sunflower heads to rot and the flowers to become damaged. To avoid this, it is important to ensure that the soil is well drained and to use a fungicide to prevent rot. Additionally, it is important to choose the right variety of sunflower that is resistant to the humid climate in Hawaii.
Another challenge to growing sunflowers in Hawaii is the lack of cold temperatures. Sunflowers need cold temperatures to form healthy flower buds, so they may not develop in Hawaii’s mild climate. If you are looking to grow sunflowers in Hawaii, you may have to bring in some cold weather to help the plant’s form buds.
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 Hawaii
Sunflower seeds should be started indoors 4 weeks before your final frost date. In Hawaii, the final frost dates are:
- zone 9: Around February 28th
- zone 10: Frost possible 12/15-1/15
- zone 11: No frost
- zone 12: No frost
- zone 13: No frost
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 9: Around January 31st
- zone 10: Around December 15th
- zone 11: No frost
- zone 12: No frost
- zone 13: No frost
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 Hawaii
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 Hawaii
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!