Growing Great Aster Flowers for Cut Flower Bouquets

Growing aster flowers is one of the wonders of the late summer garden. I tend to grow mine from seed and sow them directly into the garden in mid-May.

Why Direct Sow in Garden

I do this for several reasons:

1) it's less costly to spend a buck or two on seed packs and get tons of seed rather than a buck or two to get 4 or 6 plants.

2) Asters grow better when direct sown and are not transplanted and coddled in a greenhouse.

3) I have less incidence of disease and stem twisting when I sow and grow them directly in the garden. (yes, I can move the tiny seedlings around if I get too many in one spot)

How To Sow

For the most part, barely cover the seed and keep the seed damp and germination will follow within 10 days (at 65F soil temperatures). Cooler temperatures will delay germination.

Put the seeds approximately 2-3 inches apart and transplant the extra seedlings (when they have 4 true leaves) so that all plants are 12-inches apart.

Do this in mid to late May so the emerging seedlings will miss the last frost (they will be killed by frost). 

Indoor Sowing & Growing

You can sow dwarf aster flowers indoors 12 weeks before you want to put them in your garden if you want them in flower for mid-May.

This is the schedule professional growers use but unless you have a high-light situation, you'll be better off sowing 6 weeks before sowing outdoors so the plants are established but not too tall.

Without the high light of a greenhouse, the aster flowers will get too tall and leggy.

You can pinch them off (cut the growing tip off) if they get too tall and ugly but this will set the plant back.

Barely cover the seed, keep at 70F soil temperatures and transplant into individual pots when each plant has 4 true leaves.

Grow on in full sunlight at 65F air temperatures to reduce legginess. All asters make excellent cut flowers and can be harvested just when the flowers begin to open.

Click Here For Gardening For Beginner Gardening ebook

Book cover Gardening Non Gardening

Classes of Asters

Dwarf Asters: are usually used in pots, containers or at the front of gardens as edging. These are usually 8-12 inches tall.

Spider aster
flowers have petals that are quite thin, come in a range of colors and tend to grow 18-14 inches tall.

Powderpuffs – are an old fashioned type that look like, well a powderpuff – ball of petals. The old fashioned ones are quite tall – in the 36 inch range.

Single Flowering are daisy type blooms and tend to be taller varieties. I particularly like these.

Semi-Double The name says it all – the flowers have more than a single row of petals but not a full double.

Double The petals on these are a full double flower and resemble pom-poms in the garden

Shopping Resources for this Page

Click here for a wide selection of aster seeds

Want A Stunning Garden? Click Here For Your Free Lessons