It sounds as though your plant (Veronica spicata) may not be getting enough light. Speedwell survives in part shade but does best in full sun. You can pinch back your speedwell in spring-it may grow more compact. If you pinch back in summer, though, you may remove developing flower buds, which would prevent your plant from blooming. Your speedwell might also be getting too much fertilizer. Frequent feedings, especially if you use nitro-gen-rich materials, encourage lots of quick, tender growth. Because the plants put on fast growth, the shoots aren't as strong and are more likely to flop.