As the summer sun comes out, sunflowers will be starting to blossom for the first time in the year – and these plants are often a favourite with gardening enthusiasts.
This has always been the case – and there are many reasons for this, not least of which is the fact that they are so bright and colorful.
Helianthus annuus is the binominal Latin name for the plant and it is characterised by a large flowering head – or inflorescence.
Indeed, it is named after these huge, fiery blooms, which mirrors the shape and image that is often used to represent the sun – and this is possibly why the plants are such a favourite among children.
Flower petals are typically clustered in a spiral pattern, with each floret oriented toward the next by approximately 137.5 degrees – the golden angle. While this sounds like it would be related to access to sunlight and the photosynthesis process, it is actually from applied botany and amateur geometry.
There are usually 34 spirals in one direction on a sunflower and 55 on the other – but on very large plants there can be up to 89 and 144. This pattern was developed in order to produce the most efficient packing of seeds within the flower head.
These heads have many individual flowers, all of which can mature into seeds – and this means they often number in their hundreds, sprouting from a receptacle base.
Writing on the Organic Allotment Blog for the Observer newspaper in the UK, Allan Jenkins noted that the first sunflowers are coming out at around this time of year – and he also suggested that the many seeds matured from parent plants have resulted in this growth.
"Our first sunflower bobs about happily," he explained, adding: "We have limited ourselves to two self-seeded giants this year, in part because it is the only height we have apart from a scantily dressed wigwam. And even there, our few surviving beans are starting to snake up the poles."
Sunflowers are native to the Americas – and were only introduced to Europe in the 16th century, where they were in demand as a cooking ingredient. It has also been adopted as a symbol of some importance throughout the US – for instance, it is the state flower of Kansas.
The seeds of the plant can also be used to create sunflower greens – which are a very tasty vegetable option
Advisory website for alternative health Wheatgrass Greenhouse advises using a large planting tray, with three-quarters of a pound or just over one cup of seed per tray – with these quantities adjusted accordingly for the size of the tray.
When they have been soaked, sprouted and planted, these are then covered with a weighted tray, which will allow them all to grow at an even height. It does not matter how heavy the weight is, as the plants will not suffer. This is left over the tray for five days, being removed only once a day in order to water the seeds.
"After the five days of weight on top – maybe only four days in the summer or with a really good seed – or when the sunflower pushes that weighted tray on the floor, then keep dark for two more days, allowing them to grow taller. Turn an empty tray, upside down, and put back on top of the sunflower," the firm advice.
The sunflower shells that result from this process should simply slide off the leaves as they grow – or alternatively, they can be rubbed off when wet. "Sunflower is ready to harvest when it "joints" at the top, another set of leaves will be visible," the advisory company added.