I found the range of different seedlings in the self-sown dwarf cosmos this year interesting and thought some readers may, too. Last year, we planted seedlings of Cosmos ‘Bright Lights Mix’ (from King’s Seeds) for late summer colour in the rockery. They performed well, stayed compact in growth and provided vibrant splashes of colour at an otherwise drab time of year for that garden. Our rockery is predominantly smaller bulbs and it peaks twice a year in autumn and then in spring. Summer conditions are tough when it dries out, the soil heats up and there is little life in the soil but the cosmos didn’t turn a hair.

Because the seedlings are reasonably easy to recognise, they didn’t get weeded out but came up, bushed out and flowered in abundance over recent weeks. It is much easier if they can self-seed and not need to be raised from scratch in a seed tray and then planted out again. These cosmos are not subtle; they are perhaps reminiscent of marigolds (tagetes) but a simpler flower with clean colours so I prefer them. Cheerful, they are.

Mark’s and my early evening sitting spot is on the front porch, looking across the rockery and the variation of growth habit and flower colour caught my attention. These second generation seedlings were showing more variation than the original plants from last year. Most of the plants have remained pretty bushy and compact, which is what we want in the rockery even though we are usually sniffy about bedding plants, commonly seen in floral clocks and on traffic roundabouts. But some of the plants have reverted to the taller, more open, willowy growth that I associate with other cosmos varieties I have grown in the past.

It was the variation in colour, size and flower form that led me to picking a selection. The colour range is from a clear lemon yellow, through a gamut of golden hues to orange and then deepening to reds, but not a pure red as we know it. Some are fully single with just one row of petals, some have two rows of petals and the ones with three rows of petals are the fullest flowers on the plants. Bees love them but it wasn’t until I looked up the supplier’s website that I found out they are, allegedly, not only edible for humans but also tasty. “Flowers are edible with a sweet nectar flavour, try them in salads as garnishes or float in summer cocktails.” I have not used them as a culinary garnish, but I am sure this may be handy to know.

Most plants in the wild reproduce by seed and Nature is full of seedling variation. My cosmos are just a small example of Nature in action. When you buy packets of seed, you are trusting the supplier to have made selections from the best and most desirable seeding parents. When you save your own seed, always select from the best plant – be it garlic, tomatoes, annuals or anything else. Don’t make the mistake of saving seed from the smallest plant or fruit that you don’t want to eat. Careful seedling selection down the years is what gave us sweet corn instead of tough old maize, chunky orange carrots instead of very thin purple ones and a host of other plants. 

I may yet pull out the leggy cosmos to give more chance for the more compact ones to be the seeders but the bees will have cross-pollinated them already and any seedlings may still throw taller plants. In removing the leggy ones, I am just bettering the odds of a compact future generation.

Zach diffidently gave me a few seedlings of a named cosmos he had raised from seed. “I don’t think you will like it,” he said. “Murky colours.” He knows I prefer clean colours in the garden whereas he likes colour blends. I guess you could describe the flowers as subtle; to my eyes, they are more insipid that subtle. I won’t be sad if these ones fail to seed down.

I once photographed these tall, white cosmos in an Auckland garden. En masse, they were absolutely lovely. I even bought a packet of seed in anticipation of something similar in our blue and white Wave Garden but I am not very good with starting from seed – that is Mark’s territory. From memory, my seed was patchy in the extreme and the only plants that grew to flowering size were not pure white but candy pink and white which was not what I wanted at all. Clearly that seed had been collected from a plant that had cross pollinated with a neighbouring pink. Maybe I could try again.