I've tried it with other Pennisetum, and there was no additional blooming. The only purple variety I've tried deadheading was 'Purple Majesty,' and it added no new blooms.

I agree with Donn, deadheading blooms rarely helps promote grasses to bloom more. Cutting back foliage, however, does promote tillering and new basal growth.

My advise though with those beautiful purple fountain grasses is to leave them on their own and let them bloom like crazy in the warm weather.

Thanks for the repilies, we will let well enough alone. We have 6 container-grown plants and all started "blooming" much earlier than last year. We really enjoy the foliage and the blooms in the fall months.