Amsonia illustris

Amsonia illustris

Blue star

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Flowers
Flowers

Plant does not flower in January

Plant does not flower in February

Plant does not flower in March

Plant does not flower in April

Plant does not flower in May

Plant does flower in June

Plant does not flower in July

Plant does not flower in August

Plant does not flower in September

Plant does not flower in October

Plant does not flower in November

Plant does not flower in December

  • Botanical name: Amsonia illustris
  • Common name: Blue star
  • Family: Apocynaceae
  • Plant Type: Perennial, Deciduous
Flower colour:

Blue

Foliage colour:

Green

Known commonly as blue star, amsonias bear starry flowers from late June. Slow-growing perennials, they lack drama but make the perfect foil for a number of more dramatic and colourful plants. The different species are hard to tell apart, but Amsonia illustris has shiny green leaves and large flowers. All amsonias have milky sap, which can irritate the skin.

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Grow Amsonia illustris in humus-rich, moist soil, in full sun or semi-shade. Divide in early autumn if necessary.

How to grow Amsonia illustris

  • Plant size

    100cm height

    30cm spread

  • Aspect

    South facing, east facing, west facing

  • Position in border

    Middle

  • Sun exposure: Dappled shade, full sun, partial shade
  • Hardiness: Hardy
  • Soil type: Acidic / chalky / alkaline / clay / heavy / moist / well drained / light / sandy

Plant calendar

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Plant
Plant

Do not Plant in January

Do not Plant in February

Do not Plant in March

Do not Plant in April

Do Plant in May

Do Plant in June

Do Plant in July

Do Plant in August

Do Plant in September

Do not Plant in October

Do not Plant in November

Do not Plant in December

Flowers
Flowers

Plant does not flower in January

Plant does not flower in February

Plant does not flower in March

Plant does not flower in April

Plant does not flower in May

Plant does flower in June

Plant does not flower in July

Plant does not flower in August

Plant does not flower in September

Plant does not flower in October

Plant does not flower in November

Plant does not flower in December

Divide
Divide

Do not Divide in January

Do not Divide in February

Do not Divide in March

Do not Divide in April

Do not Divide in May

Do not Divide in June

Do not Divide in July

Do not Divide in August

Do Divide in September

Do Divide in October

Do Divide in November

Do not Divide in December

Prune
Prune

Do not Prune in January

Do not Prune in February

Do not Prune in March

Do not Prune in April

Do not Prune in May

Do not Prune in June

Do not Prune in July

Do not Prune in August

Do Prune in September

Do Prune in October

Do Prune in November

Do not Prune in December

Amsonia illustris and wildlife

Amsonia illustris has no particular known value to wildlife in the UK.

Is Amsonia illustris poisonous?

Amsonia illustris can be toxic. Its sap is toxic.

Toxic to:

Toxic to Cats

Toxic to Dogs

Toxic to People

No reported toxicity to:

No reported toxicity to Birds

No reported toxicity to Horses

No reported toxicity to Livestock

Plants that go well with Amsonia illustris