Alpine Garden Society



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Members' Articles on Propagation

It is satisfying and enjoyable to raise new plants from seed, division, cuttings or even twin scaling.  The Society Seed List provides a wonderful opportunity to raise rare or or otherwise unobtainable plants for very little cost.  By growing enough plants to sell as well as for your own use you can recoup your costs and also help our group funds. Members are encouraged to bring plants for sale to our meetings as 20% goes to the group. Simply double label the pots, one with your name and the price and the other with the plant name.

 

Advice on Seed Germination - Dr Tim Ingram
 

Many genera will germinate rapidly if sown in the spring with some bottom heat.

A number require a period of dry storage after dispersal and will not germinate if sown fresh. These include most Campanulas, Crucifers and Composites (daisies). Also Dianthus, Salvias, Digitalis, many monocotyledons and annuals.

Many alpine species show varying degrees of dormancy, mostly requiring a prolonged period of cold, damp conditions before germination can proceed (temperatures below 40⁰F/4⁰C). Seed is best sown in the autumn and kept in a cold frame over winter. Germination will normally occur the following spring. Late sown seed benefits from several weeks under warm conditions (about 70⁰F/20⁰C) before placing outside.

Many woodland species in particular wil only germinate reliably if the seed is sown fresh in late spring or early summer. Germination may occur the following autumn or spring. Particularly true for many members of the Ranunculus, Cyclamen, Jeffersonia, Mertensia, Tiarella, etc.

Relatively few species require light but it is imprtant for Lobelia, many Gentians and Foxgloves. Also some Primulas, Antirrhinum, Calceolaria and some Campanulas. Seed should not be covered after sowing or only with a very fine layer of sharp grit. Many fine-seeded species will be best kept in a propagator box to ensure surface of compost does not dry out.

Very fine seeds and Fern spores are best sown on fine, humus-rich compost first sterilised with boiling water (poured through a folded kitchen paper towel on the surface of the compost). Pots should be kept in a plastic propagator box on a shady windowsill (north facing). Often slow to germinate and grow on. Examples include Ramonda, Haberlea, some Saxifrages and Campanulas, Ourisia, Mimulus, Begonia, etc.

Hard-coated seed - especially the majority of the Legume family - require physical damage to the seed-coat before the seed can imbibe moisture and germinate. Most easily achieved by 'nicking' the seed-coat with a sharp knife opposite to the embryo. Seed of Acacia can be treated with hot water (up to 85⁰C), after which viable seed will visibly swell up. Many legumes are best sown in individual pots to reduce the risk of root damage when transplanting.

A select number of genera require two or more cold periods before germination can proceed to completion. Examples include Paeony, Trillium, Cimicifuga, Sanguinaria and some Lilies. In some cases development of the root occurs in the first season and the shoot in the second. Seed is again best sown fresh. Troublesome growth of moss/liverworts can be prevented by keeping pots in the dark.

Twin Scaling of Snowdrops - Dr Gill Regan
Galanthus 'Wendy's Gold'  

1.  Remove top third of bulb. Trim off roots leaving base plate.

2.  Soak 5 minutes in bleach, approximately 0.5%.

3.  Rinse three times in boiled water.

4. Sterilise work surface and knife with bleach or methylated spirits.

5.  Cut remaining bulb downwards into 8 pieces and then separate each piece into 4.

6.  Soak in Dithane for thirty minutes.

7.  Rinse three times in boiled water.

8.  Put in bag of damp vermiculite or perlite.

9.  Label. Put in warm airing cupboard for twelve weeks.

10.  When bulblets have formed pot up in sterile compost.
 
NB: Best done in late May. Can use Milton as sterilant.