Pruning is both a normal part of landscape maintenance and also a means to fix problems on your own plants. In addition, it can help achieve a special effect, such as determining the form a plant assumes as it rises. Understanding which plants to prune in the fall is vital in ensuring a successful result.
Blooming Time
To ascertain the best time to prune a thriving tree or perennial, first consider if the plant produces flowers. Shrubs or woody perennials that bloom in the late summer or early autumn gain from pruning in winter or fall to enhance the general form of the plant, control its size or remove dead or broken branches. These kinds of plants comprise most ornamental grasses, angel trumpet plants (Brugmansia sp.) , butterfly bushes (Buddleia sp.) , and many other varieties. On the flip side, spring-blooming shrubs such as azaleas and rhododendrons (Rhododendron sp.) Create new blossom buds throughout the summer and should be pruned early in the summer, soon after their flowers are spent. Pruning these spring-bloomers from the autumn would remove their new flower buds, preventing flower production the following spring.
Late-Fall Shaping
For non-blooming shrubs where flowering time is not a variable, fall may be a good time to clean up the plants, removing unsightly branches or giving the plant an overall shaping. But fall-pruning is best done after the plant has entered dormancy and stopped growing; pruning too early in the autumn, when the plant is still growing, can encourage tender new growth that’s particularly vulnerable to damage from cold weather. Most non-blooming shrubs such as arborvitae (Thuja sp.) and cypress shrubs (Cupressus sp.) React to late-fall, dormant pruning using a burst of new growth the next spring.
Perennial Cleanup
Herbaceous perennials that bloom in spring or summer, such as daisies (Rudbeckia sp.) , peonies (Paeonia sp.) , phlox (Phlox sp.) , iris (Iris sp.) And daylilies (Hemerocallis), gain from a general pruning in autumn to remove stems and leaf before winter arrives. These plants generally perish during winter, leaving dry brown leaf and spent blossoms. Even though you could leave these shirts in place if your plants are healthy, cutting them back helps remove any diseased or insect-ridden components, promoting healthy new spring growth. It also removes potential winter nesting places for rodents and improves the plants’ appearance during dormancy.
Perennial Bulbs
Perennial plants that grow from bulbs also gain from a late-summer or fall pruning. These comprise spring-blooming bulbs such as tulips, hyacinths and daffodils as well as summer bloomers such as hardy lilies. For those plants, the best practice would be to leave the leaf in place after blooms have faded, since the plant consumes its leaf through the summer to create nutrients it stores to the next year. When the leaf wilts and turns yellow or brown, it may be safely removed by cutting it off cleanly with a sharp knife or pruning shears.