SeptemberFlower of the Month
Perennial Sunflowers
"Helianthus"
The genus Helianthus includes the much loved annual sunflower, Helianthus annus, as well as several perennial species that make great, long-blooming garden plants. The daisy-like flowers are smaller than their annual cousins but they are profuse and long lasting. These are very tough plants, with native species found everywhere, from bogs to prairies.
Leaves- The dark green leaves can be heart-shaped or narrow and lance-shaped. The plants are multi-branched and tend to clump, although some varieties can travel by running rhizomes.
Flowers- Daisy-like yellow and gold flowers with center disks will vary slightly from species to species. There are single and double flowering varieties.
Botanical name-Helianthus spp.
Common name- Perennial Sunflower
Hardiness zone- USDA zones 4-8
Light- Blooms best in full sun, although they can handle partial shade. Without at least 5 hours of sun per day, the plants will have a tendency to get leggy and flop.
Size- Height varies greatly by species and by growing conditions. There are helianthus that reach 2-3 feet tall and others that top 10 feet. Most are clump forming spreading about 3-4 feet wide. However some will spread by rhizomes and can become aggressive in the garden
.
Bloom period- These are late season flowers, blooming toward the end of the summer and continue through the fall. You can easily get 8-12 weeks of flowers from your plants.
Perennial sunflowers make good cut flowers and attract bees and butterflies. The are also deer resistant.
Soil- Helianthus is very tolerant of most soil types and a range of soil pH. They thrive best in fairly rich soil with lots of organic matter. Although they need well-draining soil, they do not tolerate drought well, so keep them watered.
Planting- The easiest way to propagate is to divide existing plants every 2-3 years. You can plant Helianthus in the spring or fall but a spring planting will reward you with blooms at the end of the season. Space plants at least 2-3 feet apart. The can also be started by seed.
Maintenance- Plants are fairly low maintenance. They will need to be cut back in the spring and taller varieties will need to be staked or they will fall over. They need regular watering. Unless you have sufficient organic matter in your soil, you should feed them with a balanced fertilizer in the spring and possibly again in mid-summer.
Pests and problems- For the most part perennial sunflowers are pest free. They can be prone to powdery mildew but giving them plenty of air circulation will cut down on this. Dividing the clumps every few years will also aid in air flow around the stems.
Resources:
Gardening.about.com
homeguides.sfgate.com
bhg.com/gardening/plant
gardeningknowhow.com
Leaves- The dark green leaves can be heart-shaped or narrow and lance-shaped. The plants are multi-branched and tend to clump, although some varieties can travel by running rhizomes.
Flowers- Daisy-like yellow and gold flowers with center disks will vary slightly from species to species. There are single and double flowering varieties.
Botanical name-Helianthus spp.
Common name- Perennial Sunflower
Hardiness zone- USDA zones 4-8
Light- Blooms best in full sun, although they can handle partial shade. Without at least 5 hours of sun per day, the plants will have a tendency to get leggy and flop.
Size- Height varies greatly by species and by growing conditions. There are helianthus that reach 2-3 feet tall and others that top 10 feet. Most are clump forming spreading about 3-4 feet wide. However some will spread by rhizomes and can become aggressive in the garden
.
Bloom period- These are late season flowers, blooming toward the end of the summer and continue through the fall. You can easily get 8-12 weeks of flowers from your plants.
Perennial sunflowers make good cut flowers and attract bees and butterflies. The are also deer resistant.
Soil- Helianthus is very tolerant of most soil types and a range of soil pH. They thrive best in fairly rich soil with lots of organic matter. Although they need well-draining soil, they do not tolerate drought well, so keep them watered.
Planting- The easiest way to propagate is to divide existing plants every 2-3 years. You can plant Helianthus in the spring or fall but a spring planting will reward you with blooms at the end of the season. Space plants at least 2-3 feet apart. The can also be started by seed.
Maintenance- Plants are fairly low maintenance. They will need to be cut back in the spring and taller varieties will need to be staked or they will fall over. They need regular watering. Unless you have sufficient organic matter in your soil, you should feed them with a balanced fertilizer in the spring and possibly again in mid-summer.
Pests and problems- For the most part perennial sunflowers are pest free. They can be prone to powdery mildew but giving them plenty of air circulation will cut down on this. Dividing the clumps every few years will also aid in air flow around the stems.
Resources:
Gardening.about.com
homeguides.sfgate.com
bhg.com/gardening/plant
gardeningknowhow.com
