Wednesday, 23 February 2011


Thinking ahead about seeing different orchids in flower this year I am considering what I would like to see and good places to see them. Finding about where to go to see them is a matter of linking up with your local wildlife trust, natural history group or referring to books or forums.  You can of course go for walks in likely places, enjoy the surroundings and if you see an orchid that is a bonus. The critical factor is arriving at the right time which as well as being species specific is influenced by the weather.

Two weeks late has been suggested as the delay in flowering this year by some conservation organisations. There was a cold snap earlier this winter but down in Dorset it has been mild since then and melon seeds are sprouting on my compost heap.  The delay of two weeks may be accurate for the country as a whole or skewed by the heavy snow that the north of the country had for significant periods of time.

Temperature has a role to play in onset of flowering. Having spent the winter between Dorset and Kent my current feeling is that in east Dorset flowering times will be pretty much in line with the books (unless there is a prolonged cold snap between now and April). West Dorset may have been a little colder but not enough to delay flowering by more than a week. Kent seemed to have colder weather so I think that this year the glorious east Kent orchids will be about a week to ten days late.

Just as aspect influences the growth of plants in a garden it also influences the growth of wild plants. Exposed locations, north facing slopes and frost pockets will delay flowering in comparison to nearby sites or different parts of the same site that have more favourable conditions.

Phenology is not just about temperature. For orchids winter rainfall also determines onset of flowering. During winter months low levels of rainfall inhibit development of roots and tubers. As these fuel growth of flowering spikes limited winter rain can delay flowering while the plants build up reserves using water later in the year.

Regional variations also play a role. The Early Spider-orchids in Dorset are always out several weeks before those in Kent. Further north flowering times are delayed. Burnt Orchids (Neotinea ustulata) have two different subspecies  (N. ustulata subsp ustulata and N. ustulata subsp aestivalis.  So depending on which variety Burnt Orchid colonies  are composed of different timing will be required to see them.
Last year I found a few White Helleborines (Cephalanthera damasonium) in bud. According to the books they should have been in their prime of flowering, but spring and early summer were running two weeks late. I returned two weeks later to find the same plants in full flower. Additionally because plants were flowering a site which had seemed to have just a few plants was clearly full of them as they are so much easier to spot in flower.