Divide Herb Roots

How to divide herb roots

Find out how to divide the roots of herbs that produce creeping rhizomes, such as tarragon, horseradish, mint and sweet woodruff.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
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 not To do in July

Do not To do in August

Do not To do in September

Do To do in October

Do To do in November

Do not To do in December

As the weather turns colder in autumn, it’s sensible to be prepared and insure your precious herbs against damage. Herbs that are worth spending time on in the late autumn and early winter are tender herbs needing protection from frost, such as French tarragon.

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Autumn is the ideal time for taking root cuttings from herbs that produce creeping rhizomes – shoots or suckers – from the roots. Plants such as French tarragon have thick and fleshy roots that store food, enabling the root to survive and grow once detached.

The following steps are a beneficial and rewarding way to produce lots of new plants.

The steps can also be used for horseradish, mint and sweet woodruff.

Autumn is also the ideal time for taking root cuttings from herbs that produce creeping rhizomes.

You Will Need

  • Large modules or small pots
  • Compost
  • A large pot-grown plant
  • A saw or bread knife
  • Vermiculite or fine grit
  • Shredded bark

Total time: 30 minutes


Step 1

Adding compost and vermiculite to the seed tray
Adding compost and vermiculite to the seed tray

Choose large modules, or small pots. Half fill each with compost consisting of one-third finely shredded bark, one-third vermiculite and one-third potting compost. Water well.


Step 2

Sawing the rootball in half
Sawing the rootball in half

Choose a large pot-grown plant, remove the pot, then saw the rootball in half. Repot one half, using fresh compost. The remaining half can then be divided to give masses of root cuttings.


Step 3

Pruning the top growth from the cuttings
Pruning the top growth from the cuttings

Cut off the top growth from your cuttings and prune the hairy roots so that each cutting fits in a module, taking care not to damage the creeping rhizome – the engine of next year’s crop.


Step 4

Firming compost over the cuttings
Firming compost over the cuttings
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Firm into the module, cover with more compost to just below the rim, water lightly, label, then place in a cold greenhouse or cold frame. Only water again to prevent the compost from drying out completely.