Tuesday, 8 November 2011

Perfect Time To Propagate


Gardeners are always propagating plants. We get a lot of pleasure from seeing a mature plant grow from a small insignificant cutting, or packet of seeds. We know it makes economic sense to grow our own plants rather than buy them in at greater cost. However we have learnt to be patient while our wee cutting roots and slowly grows into a bigger specimen often over a couple of years.
Gardeners know the importance of getting the right variety of plant for the biggest impact, but then there is always an admirer who would just love a cutting or young plant from your impressive specimen.
I seem to have spent years travelling around the UK in my horticultural career, and each time I create a wonderful garden that I leave behind for the next person. However I always try to anticipate a move and start to propagate my specimen plants to have something for my next garden. I have many plants collected over the years that have travelled around the country with me. I am now at that stage again as I see a move coming quite soon (we are down sizing the house, but still need a big garden). I will be leaving behind a mature garden created over ten years, but really looking forward to starting a new garden venture. So the knife is sharpened and taking cuttings of my favourite plants is now in progress.
Autumn is a perfect time to propagate numerous plants. Most have finished growing for the season, and their flowering period may be over, but they are not yet dormant. The soil is also still relatively warm so root action can still be expected.
Some herbaceous plants can be split up, some alpines can also be pulled apart gently, and many shrubs can be propagated by semi ripe and hardwood cuttings. Trees and shrubs that produce berries can be propagated by extracting the seed from the berries which must be harvested before the birds eat them.

Herbaceous plants

These tend to grow in clumps that expand quite quickly. Strong pieces with good crowns can usually be dug out from the perimeter to reuse elsewhere. Replant these in drifts of three or more plants. Doronicums, Shasta daisies, phlox, delphiniums, oriental poppies, paeonias and Anemone honorine jobert will all split up easily. Flag iris has rhizomes that grow along the soil surface. These can be dug up, selecting strong young pieces with at least two or more good buds on them.
Geum Mrs Bradshaw does not form clumps readily, but it can be split up once it has been well established. Oriental poppies grow like weeds and even after they are dug up and replanted elsewhere older bits will still regrow and come back into flower very quickly.
This is an excellent time to replant lilies as the roots are still active although the tops have died down. Take care not to damage the succulent root system and as they need perfect drainage replant into holes prepared with a sandy soil mixture. They are happy to grow on a pile of stones without much soil, as they are not gross feeders but really love a dry soil surface just as long as the roots can find a bit of moisture deep down.


Some alpines such as sedum, thyme, sempervivum, campanula, phlox, mimulus, ophiopogon and saxafrages will spread along the surface of the soil forming clumps which tend to root as they expand. These clumps can be dug out and split up into smaller sections. They readily grow back into the clump or ground hugging shape. Some alpines such as primula and aquilegia are best propagated from seed using a light free draining soil mixture. Lamium White Nancy, aubretia, delosperma and veronicas are better from cuttings. Again use a free draining compost and dibble in the cuttings quite close together and place in a light but not sunny outdoor position. Most plants will be well rooted by spring and will then need potted up or planted out.
Cyclamen hederifolium and aconites can grow and spread into large drifts by self sown seed. Young plants can then be dug out of the drifts which will reform very quickly.

Take cuttings

Shrubs can be propagated by semi ripe and hardwood cuttings as well as layering.
I take semi ripe cuttings of euonymus, ceanothus, cistus and pyracantha with a heel and insert them into a closed propagator with bottom heat. Hydrangeas are best as tip cuttings of non flowering shoots protected in a cold frame
Willow, philadelphus, buddleia, forsythia and shrub roses can all be propagated from hardwood cuttings of young mature shoots about six to eight inches long and inserted into a well drained gritty mixture in a cold frame The optimum time to take  hardwood cuttings is two weeks before leaf fall to two weeks after they have lost their leaves.
Cornus is slower to root so it is better to take a bundle of cuttings and plunge them two thirds into a very sandy mixture in a cold frame. The cutting base should be callused over in early spring and be ready to line out before the buds break.
Kerria suckers very freely, so it is easy to dig up rooted stems to plant elsewhere.

Sow seed

Shrubs such as berberis, cotoneaster, pyracantha and trees such as rowan can be propagated from seed extracted from the berries as soon as possible in autumn. Sow in seed trays and leave outdoors in a shady but cold spot to stratify the seed over winter. Do not let them dry out and protect them from birds and mice. They will germinate in spring. Treat Himalayan blue poppies this way to get a good germination.


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