Dealing with Floppy Perennials
Avoid floppy perennials and eliminate the need for staking with proper selection and care.
Start by selecting plants suited to the growing conditions. You’ll get the most beauty with the least amount of effort. Pushing plants beyond their limits of preferred sunlight, shade, moisture and drought can result in weak stems.
Avoid over fertilization, especially with high nitrogen fast release products. This promotes lush succulent growth that requires more water, is prone to flopping and more susceptible to insects and diseases.
Encourage stiffer growth and reduce or eliminate the need to stake late summer and fall blooming perennials with early season pruning.
Regular division can also encourage more compact growth on some perennials. For more details on pinching, pruning and grooming see Tracy DiSabato-Aust’s book The Well-Tended Perennial Garden: Planting and Pruning Techniques.
A bit more information: Use pinching and pruning to help lengthen bloom time. Pinch back only a portion of your fall blooming plants like coneflowers in early summer. These will bloom a week or two later than the unpruned plants, extending the floral display.