Propagating Euphorbias

Euphorbias are very graphic and decorative plants in the garden. They come in more than 2,000 species and in different categories: perennials, annuals and biennials. With great variety, they offer a whole palette of shapes and colours, from green to purple, including yellow and variegated forms. Vigorous, they are easy to care for and require little. To multiply them, gardeners have several methods: sowing, propagation by cuttings and division of stumps. Here is how to propagate euphorbias.

Propagate euphorbias sowing cuttings division

Euphorbia myrsinites and 'Black Bird'

Sowing euphorbias

Euphorbias self-seed, but once established they do not like to be moved.
After flowering, which generally occurs from spring to summer, you can harvest their seeds to sow where you wish, in a sunny spot with well-draining soil. Seed capsules must be dry.
Annuals can be sown directly outside, while for perennials sowing is best done in seed trays or buckets under a cold frame.
When handling euphorbias, always wear waterproof gloves, as they contain a white toxic, irritating latex. Never touch your eyes while handling them.

Euphorbia seeds before harvest

When to sow euphorbias?

Sowing is generally done in spring, but given the variety of euphorbia species, check recommended sowing period on your seed packet.

Materials needed to sow euphorbias

waterproof gloves to avoid contact with the latex
Buckets: conventional, biodegradable or a seed tray
Light, unfertilised potting compost
Euphorbia seeds
labels
A cold frame

Steps to sow euphorbias

Harvest seeds and store them in an airtight jar in a dry, dark place.
Fill a bucket or seed tray with compost and attach a label
Moisten the compost
Scatter a few seeds on the surface and cover with a fine layer (about twice the seed size) of sieved compost
Press down lightly the compost
Water with a fine spray using a watering-can rose or a spray bottle
Place buckets or seed tray under a cold frame at a temperature of between 18 and 22 °C, in a bright spot but out of direct sun
Keep the growing medium slightly moist at all times.
To prevent the compost drying out, cover the bucket or seed tray with plastic film if necessary.
When the seedling has emerged and developed sufficient roots, you can replant it.

Propagating euphorbias by cuttings

Propagation by cuttings produces plants identical to the parent plant, which is not the case with sowing.
When carrying out this operation, always wear waterproof gloves to avoid contact with the plant's toxic latex and do not touch your eyes.

When to take cuttings from euphorbias

Euphorbias can be taken as cuttings in spring (April–May) or at the end of summer
Cut stems should be healthy and free of flower buds, flowers or fruit
Take cuttings using tools pre-disinfected with alcohol20

Materials needed to take cuttings from euphorbias

waterproof gloves to avoid contact with the latex
A bucket with drainage holes, plastic or turf
A spray bottle
A pencil or stick
A pruning shear
A free-draining growing medium made half of potting compost and half of sand

Steps to take cuttings from euphorbias

Fill a bucket with the free-draining growing medium;
Put on your gloves;
Choose a young shoot 7–10 cm long at the base of the plant and cut it, preferably just below an eye;
Place the stem in a container of water to stop the latex flowing;
Remove leaves from the lower part of the stem, leaving foliage only at the top;
Make a hole in the compost with a pencil and insert the cutting into the growing medium, firming lightly;
Place the pot in a bright spot out of direct sun;
Water and keep the growing medium slightly moist while the cutting takes.

Note that Euphorbia myrsinites is very easy to propagate by cuttings. Simply bury stems in a light, sandy soil kept moist.

Dividing euphorbias

Division of stumps is practised on perennial plants that have been in place for several years and are vigorous. It is a quick propagation technique. Again, remember to wear gloves to protect yourself from euphorbia latex. Tools should be disinfected before use.

When to divide euphorbias

Division of stumps can be carried out during the plant's dormancy, in autumn or late winter (March) for Euphorbia characias or griffithii.