Ask a gardener if they grow asters and their mind is likely to be drawn to those tall, fine daisy flowers that appear on bushy plants in autumn.
Called Easter Daisies in Australia, in the Northern Hemisphere they're known as Michaelmas Daisies or just as 'September'. It's just a case of what part of the year Autumn falls where you live!
For cut flower growers, this is a gorgeous, perennial filler flower that you can almost plant once and forget. On the flower farm, these humble plants live among the roses so they are watered and fertilised but otherwise ignored until they explode into flower in mid-summer and keep going well into autumn.
Source perennial asters as plants from good local plant nurseries or online. One of my favourites is the hard-to-find lavender-toned Aster x frikartii ‘Jungfrau’. Lambley currently has them in stock.
However it is the China Aster which is particularly useful as a cut flower.
In the UK, it is the fastest trending cut flower bought in supermarkets in the last 12 months. Why are people choosing to add it to their shopping baskets? 10-12 days vase life, a good range of colours, the trend for yellow flower centres and a relatively inexpensive price make it a popular choice.
For us as growers and gardeners, there are also lots of ticks on the checklist of what we need from our cut flowers:
- it is an annual
- easy to grow from seed
- has a long flowering window,
- a great vase life
- flowers from mid summer onwards
Mid summer can be a lull in flowering for us - the roses have finished their first flush and are slower to produce flowers due to the heat. The dahlias have started but are not in full production quite yet. Enter the China (or Summer) Aster to fill the gap!
Such a great plant but when I started cut flower growing I was far from convinced. I would end up with small plants with short stems. The flowers appeared almost as soon as the plants emerged from the ground. What was all the fuss about?
There are a few secrets to growing China Asters and the biggest one centres around day length.
China Asters are long-day plants meaning they grow vegetatively as the days are getting longer throughout spring and early early summer. After the summer solstice, the longest day of the year, the days start shortening and this (together with higher temperatures) signals to the plant that its time to start flowering.
Why does this matter? Well if you've started your seed too late and the stems are short by the middle of the year, flowers will be formed on short stems. Fine for a corsage maybe but not for a bouquet!
There is a longer explanation of the importance of day length when growing great cut flowers in my book, Secrets from the Flower Farm.
Secret 1: Sow seed early
Ideally, if you have a greenhouse or sunny windowsill, start the seed in late August to early October. Generally 6-8 weeks before you want to plant them outside.
Ideal germination temperature is 14-16 degrees but reduce the warmth if possible to 8-15 degrees for growing on.
If you need to direct sow outside, wait after the risk of frost has passed and the soil has warmed. However later direct sowing will result in shorter stems.
Secret 2: Choose your variety
The varieties we grow are Matsumoto, Balloon, King Size, and Macaroon. They have different stem lengths and flower shapes - some are single large flowers and others are sprays. Here's a summary of the differences:
| Variety | Flower Shape | Height | Colours |
|
Matsumoto |
Spray type. Flowers 2.5-5cm wide. Distinct yellow centres. | 60-80 cm | Salmon, Apricot, Blue, White, Pink |
|
Balloon |
Large domed flowers 12-15cm across. 4-8 stems per plant. | 50-60 cm |
Silver Blue, Dark Blue, Red, Rose, Chamois, White |
|
Macaroon |
Pompom shaped flowers. Similar to Bonita. | 60-80 cm | Violet, Blue, White |
The many colours and distinctive yellow centres of Matsumoto. 
Secret 3: Rotate the space
Asters are susceptible to a disease called Aster Yellows. Rotate where you plant from year to year and if you're growing lots of plants in a block, consider using row cover to exclude insects that can spread the disease.
Secret 4: Provide support and Don't Pinch
If you've planted early, you'll have lovely tall plants which will need support as they grow. I use hortonova or pea and bean mesh suspended horizontally over the beds on the flower farm but a peony spike or simple bamboo stake will do the job well for smaller numbers of plants.
Are you tempted to add China Asters to your garden this year? Let us know what you think in the comments. Happy growing!
Rebecca x