Cosmos

Cosmos bipinnatus

Sometime back, while sorting family photo archive, I came across a picture of my grandma with a bed of Cosmos bipinnatus. The photo was taken sometime back in the 60-ties, if I am not mistaken, at a farmstead of some relatives. It is also a view I remember from many other rural gardens, a sea of feathery leaves, somewhat reminding of dill, with many pastel colored daisies sprinkled on top.

I can't recall us growing cosmos in our LT garden; but that probably was more due to (non)availability of the seeds rather than a lack of interest from our part. Modest, but beautiful, it is one of the must-have flowers in a cottage or rural garden for me; or in general anywhere where a wild flower would look not out of place. Since cosmos blooms towards the autumn it is also a useful flower for extending the flowering season in the garden, and with the wide choice of the varieties available these days, it is easy to find a perfect one to match almost any color scheme.

Cosmos bipinnatus "Seashells"

So what are they? Cosmos is a genus of plants, consisting of flowering plants in the sunflower family. They are native to Central and South Americas, but nowadays also grow in a wild in parts of North America and Africa, where they were (un)intentionally introduced, like many other garden escapees. The common theory is that the missionaries in Mexico started growing them in their gardens (hence a common name Mexican aster) and from there it eventually made its way to Europe and beyond, probably somewhere in the 18th century. Usually there are two subspecies grown for ornamental purposes, Cosmos bipinnatus (purple, white and pink) and Cosmos sulphureus (red, yellow and orange), but with some of the modern hybrids it is not always easy to tell to which subspecies they should belong to. While most have the typical dill like leaves, their height, color and even bloom form can vary significantly: there are dwarf and tall varieties, singles and doubles, with curved petals, stripey, mega size blossoms and so on and so forth, sky (and funds available) is the limit.

Cosmos bipinnatus from a seed mix

Here, in NL garden, I normally sow Cosmos straight to the soil, somewhere in mid April, if we do not have a particularly cold spring. It does not seem to mind this approach, even though the soil is a heavy sea clay, but of course the germination rate usually is better in a greenhouse. Since it originates from Mexico and surroundings, it is not strange that it needs a bit of a warmth to germinate and likes heat in general (it is also a reason why it can be seeded reasonably late in the spring and still do well). They do need some sun, but they prefer poorer soils, so heavy fertilizing is not a good idea. Otherwise they require little extra care, as it often is the case with many other old garden plants. High varieties can get top heavy sometimes and flop after a heavy rain, so it is good to give them some support, either by tying them, or planting them between more stiff plants. Mildew also can be a bit of a nuisance in places where it is a common problem; I never had it here however.

If the variety is close to the wild species, they can self seed, especially eager to grow on the building sand piles and alike, but many of the modern hybrids are sterile and won't set out to conquer the neighborhood. In case the self-seeding is desired, it is best to stop deadheading them somewhere in the autumn and leave the stems to overwinter, so they have a chance to spread their seeds around. Heavy raking of the soil in the beds where they grew previously usually diminishes the chances for the seeds to germinate, so it is either leave it mostly undisturbed... Or just buy new seeds for the new season and skip the hassle, especially since there are so many varieties to try. :)

Grandma with a bed of Cosmos