16 Jul 2019

Germination investigation – Putting wildflower seeds to the test

Ardd Fotaneg · Botanic Garden

You may have noticed the plots of wildflowers in the gardens shooting up and enticing pollinators and visitors alike. These flower mixes have been designed by PhD student Lucy Witter to include the plants that are most attractive to pollinators. The flowers allow insects to load up on nectar and pollen and keep busy.

Before these flowers can be enjoyed by all however, an important process must happen – the seeds must germinate.

As part of my industrial year placement, I have been investigating the germination success of seeds from a range of different species. For each species, I have also tested a number of different seed suppliers.

For each species and supplier, I tested 100 seeds which were placed onto wet glass beads in a petri dish (damp tissue paper also works well). The plates were then stored in an incubator which cycles between 12 hours of light at 20°C and 12 hours of darkness at 17°C. The incubator was provided by the Growing The Future project and will be used for testing seeds stored in the National Seed Bank of Wales (An incubator is not essential to carry out germination investigations at home!).

Some species such as Trifolium arvense, Vicia sativa and Trifolium incarnatum require treatments to allow them to germinate, such as a cold shock or physical scarification. It is worth taking this into account when sowing your own seeds as some simple measures can greatly increase the germination rate.

The seeds got to work quickly with some species germinating within the first few days. Overall, the results were promising with most trials achieving over 75% germination rate. There were however, a few suppliers that seemed to be duds, with no seeds germinating, despite the same species from other companies germinating well in the same incubator. These results help explain why the composition of flowers seen in growing plots may be slightly different from expected based on the seeds you sow.

If you are trying to sow your own patch of wildflowers or create a natural meadow without much success, it might be worthwhile conducting your own simple germination investigation. This might reveal that changing the source of your seeds is the key to increasing the success of your efforts.