Last Updated on June 12, 2023 by Real Men Sow
Sweet autumn clematis, or Clematisterniflora, is a perennial flowering vine that blooms in late summer and early fall. Its flowers have a sweet scent. Although it can grow up to 30 feet, the average mature height is 15 feet. It grows quickly and can grow a few inches each year. The twining vine is characterized by its leathery, shiny, and dark green leaves. The flowers are small, fragrant, white, and abundant.
When sweet autumn clematis blooms cover wood fences and other structures, they can look like fleece. These are attractive, as are the fuzzy seed heads. Be aware that sweet autumn clematis is considered an invasive plant in many parts of the United States because of its aggressive growth. This plant is toxic to pets and humans.
Propagating Sweet Autumn Clematis
Clematis is not something that gardeners would ever need to grow. If you are looking to share plants, you can transplant the seedlings from a mature plant that has sprouted around it. Stem cuttings are also easy to root. You can simply cut a 4- to 6-inch length of the stem, then plant it in ordinary potting soil until the roots develop. This process can take anywhere from six to eight weeks.
How to Grow Sweet Autumn Clematis From Seed
The best time to start seeds is in the late fall or early winter. You can use ordinary potting soil to start seeds in small containers. They will grow quickly and germinate in a sunny place such as a window. Once nighttime temperatures are above freezing, seedlings can be taken outside.
General Care Guide of Sweet Autumn Clematis
Clematis autumnalis should be planted in full sunlight to ensure the best flowering. Even though these vines can grow in some shade, they are hardier than most other types of clematis.
If there is good drainage, the plant will not be fussy about soil conditions. Ideal soil should be slightly acidic to neutral soil pH. However, even slightly alkaline soils will support the plant very well.
Sweet autumn clematis needs an average amount of water. An average of one inch of water per day, either through rain or irrigation, is sufficient. This plant does not like wet soil and should be kept hydrated during rainy spells.
Temperature and Humidity
Sweet autumn clematis thrives in all climate conditions. It doesn’t require any humidity.
This plant, like all clematis varieties, is a heavy feeder. In the spring, apply a low-nitrogen fertilizer such as 5-10-10. Then, continue feeding the plants every few weeks throughout their growing season.
This vine only blooms on new wood. Prune the clematis in late fall after flowering has finished. This will prevent seed-sowing and remove any seed heads. Gardeners often trim their sweet autumn clematis plants to a minimum of one foot above the ground. If you need the vine to cover large areas, like a pergola, you can trim the plants less and leave the rest in place.
They can be grown in containers and will recover quickly from high temperatures. Plants grown in containers are fine as long as they don’t freeze.
Pests and Plant Diseases of Sweet Autumn Clematis
Like other clematis varieties, sweet autumn is susceptible to clematis wilt. The affected plants might develop dry, yellowing, or even black foliage. Remove and prune affected leaves. The disease will generally rebound the following growing season as long as it doesn’t spread to other plants.
Although they can cause damage to the plant, powdery mildew, leaf spots, rust, and viruses aren’t usually fatal. Aphids can also be caused by scale, snails, and earwigs. The appropriate insecticide or fungicide should be used to solve the problem.
Common Problems with Sweet Autumn Clematis
Clematis is a simple plant to grow and can withstand any insects or diseases. However, it can also be very easy to fix any problems that may arise.
Spots on leaves or wilting plants
Clematis wilt or leaf spot could cause dark spots on your leaves. A fungicide could be beneficial for serious problems. You should remove the affected plants if you notice yellow mottling or spotting.
White Fungal Growth
The common cause of white fungal growth on clematis leaf is powdery mildew. This can lead to leaves becoming brittle and eventually dying. Remove the affected leaves and treat them with copper sulfate or sulfur.