When to Plant Clematis

Early spring is best

Iowa State names early spring as the best time to plant clematis, and Nebraska Extension says planting is usually done in spring. A spring planting gives the vine a full growing season to build the deep root system it needs before facing its first winter. Nearly all clematis are sold in containers, because they do not tolerate much root disturbance, and that is why there is a fairly wide window for planting them.

Do not expect much top growth that first year. Clemson’s saying sums it up: the first year they sleep, the second year they creep and the third year they leap. A spring planting simply starts that clock sooner.

Potted clematis through the season

Iowa State says containerized clematis can be planted throughout the growing season. Summer planting works if you keep up with water: clematis need at least an inch a week, and a new vine has only its original root ball to draw on. Mulch 2 to 3 inches deep to keep the roots cool.

Early fall: about 6 to 8 weeks before frost

Fall is a good second window. Illinois Extension’s guidance for perennials and shrubs is to plant about six weeks before the first frost, and not too close to it. The chart above runs from about 8 weeks to 6 weeks before your average first frost. The dates for your zone above turn that into a calendar window.

Fall planting works because the soil holds its warmth after the air cools, so roots keep growing while the vine slows down. Illinois Extension also advises against fertilizing fall plantings, since new top growth would be damaged by winter. Hold the fertilizer until spring.

In cold areas, mulch the roots with 2 to 3 inches of wood chips or shredded bark. Illinois Extension says fall mulching can wait until nights get down to about 32°F, so the sun can keep warming the soil until then. Clematis grown in containers may need insulating or moving to a sheltered spot, as Nebraska Extension notes.

Timing by region

Upper Midwest and Northern Plains (zones 3 to 5). Plant in early spring. If you plant in fall, stay inside the window above and mulch well. Iowa State finds group 3 clematis, which bloom on new wood, the most reliable here, since winter dieback does not cost their flowers.

Central states and mid-Atlantic (zones 6 to 7). Early spring first, early fall second. Either way, plant the crown 1 to 2 inches below the soil.

South (zones 7 to 9). Spring and early fall both work. Clemson recommends afternoon shade in South Carolina, so a new vine planted in late spring or summer needs especially careful watering. NC State rates clematis to about zone 9, so in the warmest parts of the Gulf Coast, choose vines with care.

West. UC Master Gardeners in California stress steady moisture through hot seasons, so a vine planted just before summer needs the closest watching. Where water or soil is salty, avoid the evergreen C. armandii, which gets leaf burn.

Planting too early or too late

Clematis do not tolerate very wet sites, so in spring wait until the soil has drained enough to dig.

Planting too late in fall leaves too little time for new roots. Illinois Extension warns that plants not well anchored before winter can be heaved by freezing and thawing. A late-planted vine is most at risk in the North. If you buy one there late in the season, either plant it at once and mulch it well, or treat it like any container clematis over winter, insulated or moved to a sheltered spot as Nebraska Extension suggests, and plant it in early spring.

Whatever the date, plant the crown 1 to 2 inches deep. If the top is lost to winter or wilt, the buried buds can regrow. See how to grow clematis for planting, supports and pruning.