On Wednesday 4th September the Club welcomed Suzanne Noble* who grows native British orchids.

 

There are 25k orchid species worldwide. 80% live on trees and these are they ones you see attached to chunks of bark in garden centres.

 

In the UK we have approx. 50 species (although DNA testing is reclassifying all the time). If you already have a colony they are an indicator of a healthy, long established habitat. But often these plants have evolved to work with specific insects as pollinators: a precarious system matching the insects' cycle that could become disrupted by climate change. They also rely on naturally occurring soil fungi (mycorrhizal) to germinate. These very specific requirements and the destruction of habitats are resulting in some of our native orchid species becoming very rare. Seeing any orchid in the wild is always a thrill.

 

Orchids release thousands of tiny, powder-like seeds that get swept up into the atmosphere and can be carried many, many miles, sometimes across the Channel. Such small seeds have evolved to contain just the bare minimum: a seed coat & an embryo but no 'starter-pack' food source (as most seeds have). This means they need something to feed them once they land in order to germinate. Mycorrhizal fungi act as an intermediary between the orchid and another plant - eg: a beech tree - using that plant's nutrients and supplying them on to the orchid. In many cases once the seed germinates and the orchid grows enough to photosynthesize (convert sunlight to feed itself) the relationship is no longer needed. However, some orchids rely on mycorrhizal fungi for the rest of their lives (eg: the Ghost Orchid or the Coral Root).

 

Suzanne went on to describe the extraordinary lengths she goes to in order to germinate the seed in the lab using agar plates. Everything needs to be 100% sterile - including soaking the seed in a 10% solution of bleach. A few species can go onto the plates with the mycorrhizal fungi they need, which has been harvested. But the fungi for many others has never been identified, so instead an unexpected selection of foods has been identified that can supply the seeds with food eg: porridge oats, pineapple juice, coconut or potato.

 

Once germinated, Suzanne grows them on in specialist gel inside honey jars (see photos), until they are ready to go into pots in conventional compost. From seed to flower this takes an average of 4-5 years.

 

After hearing of this long and intricate process it is amazing that any orchids make it on their own in the wild.

 

For us humble gardeners growing orchids does not have to be so complicated - but patience is still required. Just like any other plant, match the species to your soil type & conditions: moisture level, acid or alkaline soil. Don't cut down your orchids until early September as they need 6 weeks after finishing flowering in July for the seed to ripen. Meadow grass should not be too vigorous and certainly some bare patches of soil for the seed to land in will help establishment. Finally, orchids grow very happily in pots. In a well-drained compost with added lime some of the large-flowered native orchids from Chalk Downland make stunning plants.

 

(PS: Don't grow a Lizard Orchid near to your house: its pollinators are flies and it therefore STINKS).

​

(*Any errors are due to your Admin - the note-taker).