Pushing the cuttings into the compost

How to take root cuttings

Discover how to take leaf cuttings from plants such as phlox, mint and primulas, in our guide.

A table displaying which months are best to sow, plant and harvest.
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To do
To do

Do 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 not To do in October

Do not To do in November

Do To do in December

Taking root cuttings couldn’t be easier and it’s the ideal way to increase your stock of perennials, such as phlox, rhus, mint, Japanese anemones and Primula denticulata.

There are two ways to grow root cuttings: vertically for thick-rooted plants such as verbascums and poppies, and horizontally for thin-rooted plants like Japanese anemones and phlox. We’ve shown you how to do both.

Take your root cuttings while the plant is dormant. Generally this is from around November to March, but in some spring-flowering plants enter dormancy earlier in autumn and come into flower early the following year.

More propagation content:

Follow the easy steps in this guide to propagating plants by taking root cuttings.

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You Will Need

  • Garden fork, For plants in the ground
  • Sharp knife
  • Large pots
  • Gritty compost mix, Made from equal parts grit or perlite and potting compost
  • Label and pencil

Total time:

Step 1

Method for thick-rooted plants, such as verbascums, Oriental poppies, anchusa, acanthus and sea kale

Exposing the roots of sea kale
Exposing the roots of sea kale

Expose the roots of a plant in the ground or take a new plant out of its pot. Select roots that are young, pale brown and slender – about 5mm thick.

Step 2

Dividing the root into pieces
Dividing the root into pieces

Trim off any hair-like roots and slice the main root into pieces. The length of these isn’t crucial – if you’re planting them into modules, cut them to the module depth.

Step 3

Lengths of root
Lengths of root

Line up the cuttings so you can keep track of which is the top (the end that was closest to the crown of the plant) as they won’t grow if they’re upside down. Fill module trays with a loam-based compost mixed with grit.

Step 4

Pushing the cuttings into the compost
Pushing the cuttings into the compost

Insert one cutting per module, vertically, and push it in until it’s flush with the compost surface. They’ll root just as quickly in a seed tray, but will be easier to pot up from modules and will suffer less root disturbance. Expect to see leaves developing on the top of the cuttings after a month or so, but wait a further few weeks before potting on – new roots develop after the leaves.

 

Step 5

Method for thin-rooted plants, such as Japanese anemones, phlox and hardy geraniums

Dividing the root into lengths
Dividing the root into lengths

Expose some roots of your chosen plant using a hand fork. Those on the outside of the clump will be the most vigorous. Or, lift a whole clump using a garden fork, select the best roots and cut off near the crown of the plant.

Step 6

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Slice the roots into 5-10cm lengths – the thinner the root, the longer the cutting should be. They’ll dry out quickly, so don’t delay potting them up. Fill a seed tray with a loam-based compost mixed with grit.

Step 7

Laying the cuttings on the compost
Laying the cuttings on the compost

Lay the cuttings on the surface of the compost and press them down firmly, keeping them horizontal and making sure they’re in close contact with the compost. Hold them in place with a covering of horticultural grit, which also helps retain moisture and provides drainage. Water well, from above, to ensure they’re nestled in happily, but always use a fine rose to ensure nothing gets washed away.

Step 8

Newly developed leaves
Newly developed leaves

Most of the cuttings will develop new leaves along the surface of the root after a month or so. This helps to produce a bushy plant from the start. Wait a further few weeks before separating and potting on.

 

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The right way up

Thick roots can be pushed vertically into planting holes made with a pencil. Make sure they go in the right way up. Roots will form at the end that was furthest away from the parent plant, so this end should sit in the bottom of the planting hole.

Watering can