show ponies - when do you do last clip?

[JEZA]

Im hoping to do a bit of showing with my 2 ponies next summer.
As the title says, when would you advise I do my last clip to ensure they have a lovely summer coat??
Many thanks

 

[Roasted Chestnuts]

Are they natives?

If not show as natives then i have clipped as late as march and since its been a full or hunter (minus the patch) clip.

I clipped out the PB welsh all summer last year as her summer coat was too heavy and thick for her to be comfortable competiting