7 Plants You Should Never Cut Back in October, According to Gardening Experts Don't start pruning quite yet. Close Credit: Alex Manders / Getty Fall is a great time to catch up on garden maintenance, like pruning. However, while cutting back your flowers and shrubs is often beneficial, it can also be detrimental if done at the wrong time. For example, certain plants will experience adverse effects if they're cut back in October. Knowing which plants to prune during this time of year is essential for a thriving garden. Here, we spoke to gardening experts about the ones you should avoid cutting back in October, so you don't make any costly mistakes. Karen Musgrave, an associate at Hicks Nurseries Justin Hancock, horticulturist at Costa Farms 7 Plants to Never Cut Back in September, According to Gardening Experts 01 of 07 Lilacs Credit: Elena Popova / Getty Images Lilacs are beautiful flowers that put on a show in the spring, so it may be tempting to cut them back in the fall. However, October is one of the worst times to prune them. "[They] make their flower buds the season before they bloom, so trimming them in fall could mean cutting off the buds before they ever get a chance to open," says Justin Hancock, horticulturist at Costa Farms. Instead, he recommends pruning them in early summer, right after they've finished blooming. 02 of 07 Pear Trees Credit: Getty Images It's best to wait to prune certain fruit trees, like pears, until late winter or early spring. "Pruning in the fall can accidentally stimulate new growth that can be damaged over winter," says Hancock. This damage can ultimately make your tree more susceptible to pests and diseases. How to Prune Your Pear Tree the Right Way for a Juicy, Abundant Harvest 03 of 07 Roses Credit: Masako Ishida / Getty Images Pruning roses in the fall can be problematic. Doing so can stimulate new growth that will be vulnerable in the winter, and likely destroyed by frost. "It's generally best to prune [them] back when they're dormant in late winter or early spring to prevent winter damage," adds Hancock. "Particularly if you live in an especially cold region." When to Cut Back Roses for Beautiful Blooms Every Year, According to Gardening Experts 04 of 07 Black-Eyed Susans Credit: SondraP / GETTY IMAGES Black-eyed Susans are a favorite of birds, but cutting them back in October can ruin your chances at a thriving garden full of wildlife. Their seed heads are not only a favorite snack for birds, but they also "help the plants self-sow for spring," says Karen Musgrave, an associate at Hicks Nurseries. Instead, she recommends pruning them in mid-March. 05 of 07 Hydrangeas Credit: MJPS / Getty Images You should avoid cutting back most varieties of hydrangea in October, including panicle, oakleaf, and bigleaf. "Hydrangeas can be tricky unless you know which variety you have," says Musgrave. "Many set their buds in late summer, so cutting in fall risks losing next year's flowers." Instead, she recommends pruning in late winter or early spring. 8 Vegetables You Should Plant in October for a Flavor-Packed Fall Harvest 06 of 07 Clematis Credit: Getty / Nadya SO Similar to lilac and other spring-blooming plants, some clematis species, such as montana and alpina, develop their flower buds a season in advance. "Pruning their vines means sacrificing the spring show," says Hancock. "Rather than autumn, it’s best to give these varieties a haircut right after they finish blooming." 07 of 07 Ornamental Grasses Credit: Photographer, Basak Gurbuz Derman / GETTY IMAGES Ornamental grasses should be left alone during colder weather—in October and even through the winter. "They add movement and texture [to your garden] and provide food and shelter for wildlife year-round," says Musgrave. "They also look beautiful in the snow!" She advises cutting them back in early spring before new growth appears. Explore more: Garden Landscaping