Your perennial garden still has plenty to offer as the growing season winds down. A little fall care helps plants prepare for winter, supports wildlife, and sets the stage for healthy spring growth. Knowing what to plant, what to cut back, and what to leave standing makes seasonal care easier.
Planting and Dividing
Fall’s cooler air and warm soil create good conditions for planting many perennials. Aim to plant at least four to six weeks before the ground freezes so roots have time to establish. Choose a well-drained location and water thoroughly after planting.
Fall is also a good time to divide many spring- and summer-blooming perennials that have become crowded or developed thin centers. Divide fall-blooming plants in spring, and check individual plant needs before digging. Add spring-flowering bulbs while the soil is still workable.
Watering
Continue checking soil moisture through fall, especially after a hot, dry summer. Water deeply as needed until the ground freezes, paying particular attention to newly planted or divided perennials. Keep the soil moist without leaving it soggy.
Plants such as lavender, baby’s breath, and culinary sage need excellent drainage, particularly in winter. Let soil conditions and each plant’s needs guide your watering.
What To Cut Back
Allow healthy foliage to remain until it naturally yellows or dies back. While leaves are green, they continue producing energy that plants store for the following season. Many healthy stems and seed heads can stay through winter.
Remove diseased foliage and stems to help reduce problems next year. Keep infected material out of your home compost pile. For plants that spread readily by seed, remove spent flowers before seeds mature if you want to limit seedlings.
Avoid heavy fall pruning of woody plants such as Russian sage, butterfly bush, bluebeard, lavender, and culinary sage. Assess winter damage and prune as appropriate in spring. Leave healthy coral bells foliage in place, and check your clematis variety’s pruning requirements before cutting it back.
Winter Interest
Standing stems and seed heads add texture and beauty long after flowers fade. They also provide food for birds and shelter for overwintering insects. Ornamental grasses bring color and movement, while snow resting on sturdy seed heads adds another layer of seasonal interest. Leave healthy plants standing where practical, then tidy selectively in spring.
Mulching for Winter
Winter mulch helps moderate soil temperatures and reduces repeated freezing and thawing, which can push plants out of the ground and damage roots. Newly planted, recently divided, and less winter-hardy perennials benefit most from extra protection.
For an insulating winter covering, wait until plants are dormant and the soil begins to freeze. Use loose materials such as shredded leaves or weed-free straw, and avoid packing wet material against plant crowns. Keep bark mulch between plants rather than piling it over them.
As temperatures warm in spring, gradually pull back the winter covering so emerging growth has room to develop.
