How to Grow and Care for Jackman's Clematis

Jackman's clematis is one of the most popular of all flowering vines—so commonly grown that some gardeners despise it for its very popularity. But popular plants generally gain their popularity for good reasons. Jackman's clematis is a vigorous yet compact vine with fabulous flowers. Its large 5-inch blooms are a delicious dark purple, making it one of the prettiestflowering vines. Clematis vines are often used to camouflage eyesores in the landscape, or forlandscaping around mailboxes, where the vine is trained up a mailbox post as a decoration. It can be trained up almost any vertical structure, from garden walls to small trees.

Clematis can be planted in the spring, late summer, or early fall.

Like all clematis, it is toxic to humans and pets.

Jackman's Clematis Care

Here are the main care requirements for growing a Jackman’s clematis:

• Plant it in well-drained soil with the top of the root ball a full 3 to 4 inches below the level it was in the nursery pot. Planting at this depth promotes the development of "latent" buds below ground level.
• Water it regularly in the absence of sufficient rain to keep the soil evenly moist.
• Provide support such as a trellis or let it climb upon other shrubs and vines.
• Cut the plant back in the fall to "hit the reset button" for next year.​

Light

Treat this flowering vine asa perennial vine for sun in the north. But it can take a bit more shade than can many other types of clematis; in the south, it is a good idea to give it partial shade.

Soil

Jackman's clematis prefers fertile, well-drained soil. A major soil consideration in growing Jackman's clematis is to keep the soil relatively cool.

Water

Do not let the soil dry out completely at any point during the period of active growth for the plant. It very much prefers consistent moisture.

Temperature and Humidity

While Jackman's clematis likes warm weather, it does not do well in excessive summer heat, especially if it is planted in a location where the root zone gets hot. It does not have any particular humidity preferences.

Fertilizer

If you are an organic gardener, fertilize the clematis withcompost. Otherwise, apply acomplete fertilizereach spring, then monthly through the growing season. When using commercial fertilizers, err on the side of too little rather than too much.

Types of Jackman's Clematis

Jackman's clematis is not the only clematis variety with bluish or purple flowers. Others include:

• C.'Etoile Violette' has smaller blooms than Jackman's clematis and blooms through the end of the summer.
• C. x Durandii is a non-twining clematis that will sprawl over the ground unless manually tied to a vertical support. It blooms for a remarkably long time, through the entire summer and into fall.
• C. 'The President' has huge flowers that bloom twice—in late spring and early summer, then again in late summer and early fall. Vines grow as much as 10 feet tall.
• C. macropetala'Maidwell Hall' has smaller, nodding flowers with white centers. This easy-to-grow vine has a maximum height of 6 to 8 feet.
• C.'Venosa Violacea' has large 6-inch flowers with petals that are white with purple margins. It grows 9 to 12 feet tall.

Pruning

For pruning purposes, Jackman's clematis is considered a "group 3" clematis that blooms on "new wood"—producing flowers on stems that have grown in the current growing season, not last year's growth. This means that the best time to prune the vine is from late fall to early spring, after flowering is complete but before new growth has begun.

It is best not to prune a new vine very much, giving it time to put on some growth (unless it is to remove dead branches, which can be done at any time) But once it matures, a clematis may begin to lose vigor or become overgrown, and this is the time to begin an early spring pruning regimen. While some perform a drastic pruning, most growers prune clematis in a more targeted fashion, cutting the vines down to a preferred height where there are good leaf buds present.

Propagating Jackman's Clematis

Clematis can be propagated with cuttings made from new, soft green growth.

1. Take a cutting below a leaf node. Your cutting only needs one leaf stem, so trim off any extras.
2. Dip the cut ends in rooting hormone. Fill a 4-inch pot with potting mix. Lay the cuttings on top horizontally. Lightly cover with potting mix and moisten the top with water.
3. Place the pot in a clear plastic bag and keep it in bright but not direct light, Keep the soil evenly moist but not soggy. In about four weeks, the cutting should have rooted. You'll see new growth and the cutting won't wiggle when you gently tug on it.
4. Transplant each rooted cutting in its own pot. Leave it in the pot for another growing season and harden it off before transplanting it outdoors.

How to Grow Jackman's Clematis From Seed

This variety is a hybrid and seeds collected from it won't produce plants that are true to type. Therefore growing it from seed is not recommended.

Potting and Repotting Jackman's Clematis

Due it its size and fast growth rate, Jackman's clematis is not the best clematis to grow in a container. A non-vining, bushy clematis such as Arabella clematis (Clematis x 'Arabella') is a much better choice for pots.

Overwintering

Jackman's clematis is a hardy plant but it still needs winter protection in the form of mulching. Apply a layer of at least 2 to 3 inches of mulch around the base to protect the roots from the freezing temperatures.

Common Pests and Plant Diseases

Slugs like to eat clematis almost as much as they do hostas. If you use stones to shade the base of the plant, lift them often to check for slugs napping beneath. Dispatch any slugs that you do find. Pest damage can also come from earwigs and spider mites.

Clematis wilt, a fungal disease that attacks the base stems of the plant, can be fatal to clematis. Its symptoms are a sudden progressive shriveling of the entire plant, usually in early summer. Black spots on the leaves may be evident. There is no cure for clematis wilt, but you may be able to prevent it by keeping the soil evenly moist, making sure the soil is neutral or slightly alkaline, and watering at the base of the plant rather than on the leaves.

If clematis wilt appears, remove all damaged portions of the vine. If the root system is strong, the plant may recover by the next season.

How to Get Jackman's Clematis to Bloom

If your clematis is not blooming, it could be improper pruning, too much nitrogen fertilizer, drought stress, or too little sunlight, Make sure to prune in the fall or winter, use a fertilizer high in phosphorus, and give the plant enough water. As for sunlight, check if surrounding plants cast too much shade on it, which can be often remedied by pruning them.

Bloom Months

The vine starts blooming in early summer, typically in June, and continues to bloom to late summer, in favorable conditions even into September.

How long does Jackman’s Clematis Bloom?

The plant blooms consistently for a couple of months or more during the summer. It reblooms every year but it may take the plant a couple of years to fully bloom, true to the saying about clematis. “The first year they sleep, the second year they creep, and the third year they leap.”

What Do Jackman’s Clematis Flowers Look and Smell Like?

The flowers are large, up to 5 inches in diameter, open-faced and deep purple. Jackman’s clematis is one of the most fragrant clematis but the smell of the flowers is rather subtle—you need to bend over the flower to notice it.

How to Encourage More Blooms

After the first flush of flowers in the early summer, you can cut the vines back to the large buds, which will encourage a second flush of flowers. Deadheading the flowers won’t promote a longer bloom and thus isn’t necessary other than for aesthetic reasons.

Caring for Jackman’s Clematis After It Blooms

There is nothing to be done right after the bloom. In the fall, however, after the plant had died back, prune it sooner than later in order to remove any diseased foliage.

Common Problems with Jackman's Clematis

The roots of clematis do not like heat so it is critical to shelter clematis roots from the blazing sun. You need to take measures to keep the roots cool. The practice of deep planting helps keep the roots cool. Another way to keep your vine's roots cool is to spread about 2 inches of mulch over the root zone. Other gardeners shade the base of the vine with ground covers, which is not ideal because they can interfere with the root system of the clematis. Still others place flagstones or other objects at the base of the clematis to cast shade. However, the latter practice can provide an open invitation to slugs.

From: thespruce