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How to divide iris rhizomes

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To do
To do

Do not To do in January

Do not To do in February

Do not To do in March

Do not To do in April

Do not To do in May

Do not To do in June

Do To do in July

Do To do in August

Do not To do in September

Do not To do in October

Do not To do in November

Do not To do in December

Irises can become congested over time, which tends to inhibit flowering. This can be remedied by lifting and dividing their rhizomes to give them a little more space. Wait until flowering is over before dividing the iris clump, discarding any old, woody rhizomes and replanting only young, healthy plants into freshly-prepared soil.

You will need

  • Irises
  • Garden fork
  • Sharp knife
  • Trowel
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Total time:

Step 1

Use a fork to dig up a congested clump of irises. Ease the plants from the soil, taking care not to spike the rhizomes.

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Step 2

Pull the congested rhizomes apart by hand, or cut them with a knife. Choose healthy pieces with leaves and discard old, woody sections.

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Step 3

Newly-planted rhizomes are vulnerable to wind rock, so it’s a good idea to reduce the leaves by half. Use a sharp knife to trim them.

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Step 4

Replant healthy rhizomes about 12cm apart with the leaves facing towards the sun. Make a shallow hole and half bury the rhizome, giving it a firm push to bed it in – they like to bake in the sun, so don’t bury them too deep.

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It’s a good idea to lift and divide clumps of irises every three years.