Question 1

What is Yellow Rattle

Accepted Answer

Yellow Rattle is hemiparasitic and is used to create or restore wildflower meadow habitats, where it maintains species diversity by suppressing dominant grasses, recycling soil nutrients, and allowing other species to thrive. 
It attaches itself to the roots of adjacent grasses leeching the nutrients from them. The yellow flowers make way for seed pods that move in the wind and give the plant its name. Traditionally called the "Meadow Maker", farmers removed it from their crops because it suppressed yields at harvest time. However, in habitat recovery or biodiversity contexts, Yellow Rattle has many benefits.      
The disc-shaped seeds are best sown thinly from September to November -  to germinate the following spring. The seeds need to remain in the soil throughout the winter months so that the frosts trigger germination. A process called vernalisation.

Question 2

When to plant Yellow Rattle

Accepted Answer

Yellow Rattle needs frosty conditions to germinate,  a process called vernalisation, and ideally needs about 4 months below 5C to germinate in the Spring, when the yellow flowers make way for seed pods that rattle in the breeze. It is best planted in the Autumn.

Question 3

An alternative way to grow Yellow Rattle

Accepted Answer

Yellow Rattle needs frosty conditions to germinate and ideally needs about 4 months below 5C to germinate in the Spring. However, through a process called stratification, it is possible to mimic the winter months to cause the seed to germinate.
This can be achieved by placing the seeds in a fridge for some time to the seasonal drop in temperatures associated with frosts and snow, encouraging the seed to germinate once placed in the ground and warmed again. Keep the seed packets well labeled if you follow this method.  
Placing the seeds in the fridge or freezer aims to speed up the ‘cold’ period, and is the nearest thing to a ‘calendar’ to tell the seeds when to germinate. It's a proven method that encourages vernalisation or germination.