These perennials won’t grow well if you plant them before winter.

Published on September 25, 2025

Credit:

Jacqueline Anders / Getty Images

Fall is the best time to plant spring-flowering bulbs and native plant seeds that benefit from cold stratification, like milkweed and bee balm. However, fall planting is not recommended for certain types of tender perennials that are easily damaged by cold and require a long period of frost-free weather to root. To help guide your fall gardening to-do list, here are 10 common perennials you should avoid planting in autumn if you want them to thrive.

Canna Lilies

Credit: Blaine Moats

Although canna lilies (Canna spp.) are treated as annual plants in cold climates, these flowering plants can be kept as perennials in USDA Zones 7–10. However, because canna lilies are easily damaged by frost, they shouldn’t be planted in fall, even in areas where they’re winter hardy. Instead, plant canna lilies in spring through early summer, dig up the rhizomes in fall, and overwinter them indoors if you want canna lilies to survive the winter in Zones 6 and colder.

Tender Salvias

Credit: Marty Baldwin

Hardy salvia plants can be planted in spring or fall, but tender salvias, like pineapple sage (Salvia elegans) and Mexican bush salvia, should only be planted in spring. Many of these plants are only winter hardy in Zones 8–11, and even mild winter temperatures can make it hard for them to root. For better results, plant these delicate beauties in spring after the danger of frost has passed.

False Indigo

Credit: Blaine Moats

Compared to canna lilies and tender salvias, false indigo (Baptisia spp.) is a relatively hardy plant, but it still grows better when planted in spring. These perennials need plenty of time to develop a robust root system before winter, and they may not have enough time to establish themselves if you plant them in autumn. False indigo is cold-hardy in Zones 3–8.

Bougainvillea

Credit: Denny Schrock

Bougainvillea plants (Bougainvillea spp.) are famous for their vibrant flowers that bloom from spring through fall in Zones 9-11. While bougainvillea can be planted in early autumn in warmer areas, these tropical plants usually fare better when planted in spring or summer. Earlier planting gives bougainvillea more time to become established in the garden, and it helps the plants flower better the following year.

Dahlias

Credit:

Lynn Karlin

In cold areas, dahlia tubers (Dahlia spp.) are usually dug up in fall and overwintered indoors, although plants can be left outside all year round in Zones 8–11. No matter where you live, planting dahlias in spring is always the best choice since dahlias do most of their blooming in summer and fall. Not to mention, planting dahlias in autumn increases the chances that you’ll lose your tubers to cold or rodent damage.

Gladiolus

Credit: Alison Miksch

Gladiolus can be left in the garden through winter in Zones 8–11, but gladiolus corms need to be overwintered indoors in colder areas. Spring planting safeguards tender corms from cold damage and reduces the chances that hungry rodents will gobble up your plants before they sprout. Keeping gladiolus and other bulbs in bulb cages or a DIY cage made of chicken wire can add extra rodent protection and make sure nothing nibbles on your plants.

Mandevilla

Credit: Bob Stefko

A heat-loving plant, mandevilla (Mandevilla spp.) is mostly grown as an annual in North America, although some gardeners bring potted mandevilla indoors in winter. However, if you live in Zones 9–11, you can grow mandevilla outside year-round and use this tropical vine to accentuate arbors, fencing, and more. Just keep in mind that mandevilla is sensitive to freezing temperatures and should only be planted outside when the weather warms in spring.

Lavender

Credit: David Patterson

Growers in mild climates may have success planting lavender (Lavandula spp.) outside in the fall, but these plants need to be in the ground at least eight weeks before frost is expected. When lavender is planted later in the season, plants may not have enough time to become established before winter, and they may not return in spring. Beyond that, lavender plants prefer dry conditions, and they’re more prone to fungal issues if they’re planted in autumn when rainfall is more abundant. They are cold-hardy in Zones 5–9.

Rosemary

Credit: Denny Schrock

Like lavender, rosemary (Rosmarinus officinalis) prefers relatively dry conditions. In wet weather, it can develop root rot or issues with powdery mildew. However, rosemary is even less cold-hardy than lavender, and most rosemary varieties only grow as perennials in Zones 8–10. Even in these areas, rosemary must be planted well before autumn to ensure its roots are sturdy enough to carry it through the winter.

Tuberose

Credit:

Dean Schoeppner

Night-blooming tuberose (Polianthes tuberosa) should only be planted in spring after the danger of frost has passed. Tuberose bulbs planted in fall are much more vulnerable to rot, and they might not have enough time to root before winter. The good news is that tuberose plants flower about 90 to 120 days after planting, so you should still have plenty of time to enjoy their blooms even if you plant in spring. This lovely night-bloomer is cold-hardy only in Zones 7–10.