|My daffy dahlia - posing for its photo in the large terrace bed|
Whilst I was out in the garden last week, I noticed something slightly different in one of my bright yellow "dinner plate" dahlias. This plant is in its third season here and it's the first time I've seen a streak of red on any of the petals.
Just one flower is affected, so what's going on?
Four possible reasons spring to mind: environmental impact, genetic mutation, reversion, or a reaction to a virus.
It's all in the genes?
Going back to mum or dad
Give them a break
Quite often with a virus, infected plants get steadily weaker until they no longer bloom. This is what happened to some of the popular tulip varieties in the past. So next year I'll look for more red streaks on blooms and/or any signs of weakening of the plant.
What a living botany lesson my garden is turning out to be. There's always something new to observe and learn, so I'm adding a new Botany label to the blog - to gather together my lessons from VP Gardens.
I popped into the RHS Shades of Autumn show in London yesterday to ask their advisory service about my dahlia. They say it's a chimera, i.e. material which is genetically distinct from the rest of the plant. Apparently this phenomenon is often seen late on in the season in plants like my dahlia, and it's usually a reaction to environmental factors such as temperature fluctuation.
There are other ways in which chimeras occur, most of them linked with a genetic mutations of some kind. Many of our variegated plants are chimera, with the paler foliage genetically distinct and living alongside the green. As the pale foliage has no chlorophyll, it is dependent on the green foliage for its survival.
Some grafted plants are chimera too and that's the exception to the cause being genetic. It's great to have got to the bottom of the cause so quickly and to have something so interesting happen at VP Gardens.