Sunflowers die after the flowers have turned into seeds. They do not grow and therefore do not flower from that moment on. It is usually at this time that the flower heads begin to point towards the ground rather than east.
Sunflowers stop growing when the flowers start to turn into seeds. During this phase, the stems turn from green to yellow and then to brown, and the flower heads begin to face the ground rather than east.
How tall does a sunflower have to be to flower?
In most cases, the sunflower is not a difficult plant, it can grow in most climates, its flowers start growing when the sunflower measures between 3 and 16 feet tall. Its flowers, of a yellow/bronze orange color will give a fancy touch to your garden.
How the sunflower follows the sun
Moreover, on the face of the plant exposed to the Sun, the luminous rays degrade the auxin more quickly than on the face in the shade. Thus, more concentrated on the side in the shade, this hormone causes a more intense growth of the cells.
This is why plants follow the movement of the Sun, even though the intimate details of this process are still poorly understood.
On the other hand, in the case of sunflowers, only the young plants and each of their leaves follow the movement of the Sun, hour after hour, day after day. Once the flower has formed, it freezes in the direction of the rising Sun.
When to plant sunflowers?
Sow outdoors from the end of April, when the risk of frost is over, until mid-June. You can stagger the sowing to prolong the flowering.
Plant perennial sunflower seedlings in pots in the fall or spring.
Where to plant sunflowers?
The largest sunflowers can be placed at the bottom of a bed, against a fence or hedge or in groups in the vegetable garden.
They can be used as stakes for climbing plants such as ipomea or Spanish beans. The dwarf varieties can be placed in pots or planters where they liven up balconies and terraces.
Growing sunflower in pots
Growing potted sunflowers is quite possible and even a very good idea for those who have a terrace or balcony.
Take a pot of sufficient diameter to allow the roots to develop (about 30 cm minimum).
Fill with potting soil
Make a small hole in the middle and put 3-4 sunflower seeds in it.
When your sunflowers have formed 3-4 leaves, keep the most vigorous young shoot.
Continue to water regularly
In pots, it is often preferable to place a stake to prevent the sunflower from collapsing under the effect of the wind.
Do Sunflowers need lots of water?
This is one of the key points in sunflower care, especially if it is grown in pots. The sunflower does not especially need more water than other plants.
The sunflower fears drought and should be watered when the soil is dry.
It fears too wet soil and should therefore be watered moderately.
Potted sunflowers require regular watering as soon as the soil surface is dry.
Multiply the sunflower
The sowing of the sunflower is practiced directly in place, during April and until the end of June, by covering the seeds with about 2 cm of soil.
It is of course possible to prick out the plants, but it is better to avoid doing it: sunflower seedlings hardly support transplanting. One can also sow the sunflower seeds in buckets, under cover, in March-April.
There are perennial and annual species, but it is the latter that are most often cultivated.
Among the perennial species are helianthus decapetalus and atrorubens.
They are relatively tall but do not reach the heights that annual species can reach.
The most common annual sunflower is helianthus annuus with large flowers that can measure up to 40 cm in diameter and their large size, up to 4m high.
If you wish to create a sunflower hedge, you can choose the helianthus Russian Giant, a nice way to delimit the vegetable garden or a summer corner to rest…in the sun.
For your cut flowers, the helianthus ‘Prado Red’ is ideal because the flowers are not too big (about 10 cm in diameter) and stand up very well in a bouquet.
Cooking the sunflower
That’s not all: sunflowers can have a… greedy use! Its young floral buds, which are still very tender, can be blanched in boiling water and then returned to butter with a little garlic; they then develop, according to some, a flavor of artichoke heart.
Its petals liven up green salads thanks to their bright color and nutty taste. Not forgetting the sunflower seeds that are roasted and served as an aperitif.
The composition of the sunflower (Helianthus annuus) has greatly evolved since its appearance in North America. Today, its richness in omega 6 and omega 9 as well as its antioxidant properties make it a highly appreciated plant, both by humans and farm animals for their food.
Indeed, the sunflower dies as soon as the flowers have finished turning into seeds. They stop growing and flowering from then on.