Helianthus maximiliani

Most gardeners are familiar with the annual sunflower, with the dinner-plate sized flower on a single stalk. While those are great fun to grow, most of us don't have the room for them.
The vast majority of the sunflower genus are annuals. However, it is the perennial varieties that coexist most happily with other garden plants, and once planted, require little more attention than an annual cutting to the ground when they go dormant in winter, but bounce back to life and burst into dramatic display every August.
Perennial sunflowers can either be grown in rows at the back of the border or to make summer screens, as features in cottage gardens or for their cut flowers. They also work well when grown as repetitive clumps alongside ornamental grasses in naturalistic or prairie style gardens. Clumped together in a large colony, their simultaneous blooms look like a huge summer bouquet.

Perennial sunflowers typically don’t grow quite as tall and large as their annual friends. However Helianthus maximiliani is a wonderful exception. It grows slowly through the summer months as a group of short stems, until late summer when the stems bolt and the flowers head for the sky.
The plants usually grow to around 90 to 180cm (3 to 6ft) tall, but in good conditions and if left unpruned individual plants can reach heights around 250cm (8ft) with a spread of about 1m (3ft).

Helianthus maximiliani might not be a plant for small gardens, but is a great plant in the right place.
It grows fast, is drought tolerant and thrives in well-drained soil and bright sunshine. Blooming in August to September, they produce large bright yellow flowers 7 to 12cm (3 to 5in) in diameter in a spiral around the stem. They flower fairly late in the season putting on quite a show in the waning days of summer and providing colour when little else is blooming.
Butterflies and bees love the sweet pollen and songbirds gain sustenance from the abundant seeds.

Sowing: Sow in Spring
Sow 3mm (1/8in) deep in trays or pots containing good free draining seed compost, Make sure that the compost is kept moist but not wet. The seeds germinate best after a period of cold so place the container in a cool position. Germination usually takes 21 to 30 days at 16 to 20°C (60 to 70°F).
Transplant when large enough to handle into 9cm (4in) pots or boxes and grow on in frost free conditions, in a cold frame or cold greenhouse until large enough to plant outdoors. Acclimatise young plants to outdoor conditions before planting out into ordinary garden soil in full sun 40 to 60cm (16 to 24in) apart.
Pinch about 25mm (1in) from the tips of stems to promote bushy growth with multiple branches and more blooms. Pinch the plants often throughout the blooming season to keep the plants compact and healthy.
When the plants are well grown, acclimatise them to outdoor conditions over 7 to 10 days. Transplant outdoors to a sunny, sheltered position on moist, well drained soil. Plant in a position where the plant is able to grow in subsequent years.

Cultivation:
Best grown in average, dry to medium, well-drained soils in full sun. They tolerates drought and can be grown in a wide range of soils, including poor sandy soils, humusy loams and clays.
The plants do not use a lot of water so once established does not need watering or any other care. They don't need fertilising either, this will often produce lush growth and weaker stems which then flop over.
In exposed areas stake the plants, as tall plants are often damaged in rain or strong winds and may flop over while in bloom especially it is grown in moist rich soil. Simply drive a wooden or bamboo pole into the ground, and then tie the plant to the stake loosely with a piece of soft string.
Beware of snails and slugs when they are still young plants. Other than that, they are delightfully uncomplaining and easy to grow.

Pruning:
Tall varieties of perennial sunflowers benefit from pruning to control their height and to help them grow thick and lush with lots of flowers. It also keeps them from flopping over when hit by rains, especially when grown in moist rich soil.
To control the height, cut the stems back by one-half, in late spring or early summer, then, if necessary by another one-third a month later. You can cut late blooming varieties a third time if necessary until late summer, but once the buds form, stop pruning.
Pinch or cut off spent flowers when they begin to fade to encourage perennial sunflowers to produce more blossoms. Do this throughout the flowering season until the last wave of flowers, usually in late summer or autumn.
Cut back perennial sunflower plants to the ground in fall after they are finished blooming and the foliage begins to fade. Do this to clean up your garden, if desired. If you wait until late winter or early spring to cut them back, the seeds will provide food for the birds during the cooler months.

Harvesting Cut Flowers:
For the vase, cut the fresh flowers in the morning just after they open, but wait until the sun has dried the dew. Remove leaves that are low on the stem, leaving just two or three higher up, near the flower's face. Place the flowers in a bucket filled with water, and leave them to stand for several hours in a cool room before placing in a vase.
Use a clean knife, a clean vase and a few drops of bleach in the water to keep it fresh. Change the water every few days. Blooms can last up to a fortnight when kept in water.

Plant Uses:
Naturalistic or Prairie style gardens, Cottage & Informal Garden, Wildlife Gardens, Flower Arranging, Children.

Harvesting Seed:
If you want to collect your own seed you many need to bag the heads with a paper bag to ensure you get there before the finches as they love these seeds. To dry seeds, cut the flower heads off when they begin to yellow at the back. Hang them upside down in a dry location away from rodents and birds. Store in a cool dry place until you are ready to sow.

Origin:
Native to central North America, it is found from Missouri and Texas to southern Canada. It is native to the Great Plains and former tall grass prairie regions and is typically found today in dry open areas such as prairies, bluffs, limestone glades and roadsides.

Nomenclature:
The genus name Helianthus is taken from the Greek helios, meaning sun, and anthos, meaning flower. Together they give the plant its common name of Sunflower.
Both the species name Maximilianii and the common name of Maximilian Sunflower honours the German Prince Maximilian of Wied-Neuwied (1782-1867) an early botanical explorer of North America who discovered this plant. He explored parts of the American West in 1832 to 1834 and journeyed in the Great Plains to study the natural history and anthropology. He published the two-volume 'Travels in the Interior of North America' in 1839-41.