See the footnotes for the question I now have about variegated plants - your help with the answer is appreciated...
Another sign the nights are drawing in is the garden lectures start up again. For Threadspider and I this means a monthly trip to Bath until May to hear whoever's been tempted over by Derry Watkins.
As usual it's a cracking programme and first up a couple of weeks ago was Bob Brown, the renowned nurseryman of Cotswold Garden Flowers. His subject was Propagating Your Plants and he apologised for short changing us as his talk is usually combined with a practical session at his nursery. Sign me up immediately!
It was a most entertaining talk, shot through with a dry sense of humour and questions barked out at the audience. He gave us so much information that I'm going to divide this post into two. First up are some of Bob's observations on perennials...
There's a number of reasons why propagation by seed for perennials isn't usually as successful as for annuals - and it's not because Bob's a nurseryman so he wants you to buy his plants!
- Seed production isn't usually as prolific because these plants don't need to invest all of their reproductive strategy into seed production. Their numbers may be less or it takes several years before any are produced at all
- Seed germination rates decline very rapidly due to increasing concentrations of germination inhibitors. Derry added she likes to sow her collected seed fresh or at the most within six weeks because of this. She's also noted seeds sown after this time and left around her nursery might start germinating some years later. This suggests seed viability isn't the issue in these cases
- The seed of named cultivars doesn't come true* so what you'll actually get is a bit of a gamble as it's not stable**
- Variegated plants are actually 1 plant within another aka a chimera***. The seeds are formed from one plant (whichever colour forms the edge of the leaf) and the roots are the other. To retain the variegated form propagation by cuttings or division is required
I've always looked at the lists of plants given for a particular propagation method and wondered how you decide the best method for a plant that's not on the list. I now see that understanding the type of plant it is (e.g. hybrid, chimera etc) and the way it grows give major clues as to which technique(s) are the most likely to be successful. I need some further study before I can make my own predictions with confidence.
Next week, I'll share the tips I gleaned from Bob as my 'starters for 10'.
* = this suggests they're the same generation as the F1 hybrids we encounter in the vegetable and fruit growing world i.e. they're the first generation of plants produced after the parent plants have been crossed?
** = however Bob did encourage us to try sowing dahlia seed collected from our plants as a fun thing to do. As they're tender plants, the seeds need to be saved until April the following year - an exception to the sowing fresh rule!
*** = therefore does that mean all variegated plants are chimeras, but not all chimeras are variegated plants?