This section is from the book "The Gardener V3", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
These are one and all greatly benefited at this time by having all seed capsules and pods removed. Very few of the Violas bloom later than September. The only one which we have this year given a prominent position to is Downie & Laird's Duchess of Sutherland. It is like the old Golden Perpetual, in that, like it, it would flower continuously, summer and winter, did weather permit. The great fault with most Violas is their habit in this dry climate of thus ceasing to flower early in autumn. The practice of removing the seed-vessels twice throughout the summer is the best means of getting them to continue in a floriferous state.