Clematis

Planting & Pruning Clematis

Types of Clematis
There are three basic types of clematis; ones that produce flowers on this year's growth (new wood); ones that produce flowers on the previous year's growth (old wood); and those that produce flowers on both new and old growth. Knowing the variety you have is essential in order to know the proper pruning technique. (see below)

Clematis Varieties A - K
Clematis Varieties L - Z

Location
Clematis require a site that will receive at least one half day of direct sunlight. This helps in bud and bloom production, and in lowering susceptibility to crown rot. Young clematis are extremely susceptible to crown rot, which is a disease. Crown Rot can usually be prevented by treating the plant with a garden or flower fungicide throughout the growing season.

The plants are also susceptible to any root disturbances. These can include animals digging around the roots, or growing in a low spot where water may collect.

Clematis like to have a cool root zone. Place a layer of mulch around the base (not exceeding 1.5") of the plant or plant clematis by shrubs, perennials, or annuals that will shade the root system. A "pinch" of lawn and garden lime or about a half cup mixed in a hole 1' in diameter and 1' deep is helpful as clematis prefer a slightly alkaline pH.

Give Clematis time to get a good root system established before you expect flowers. This may take a year or two. Double flowering varieties may take a bit longer.

Pruning
Knowing the variety you are planting is essential in order to know the proper pruning technique. Check your plant for either A, B or C and follow the pruning instructions below:

Group A: Early-flowering Clematis
Plants in this group bloom in early spring, generally in April and May, from buds produced the previous season. Prune these back as soon as possible after bloom but no later than the end of July. This allows time for new growth to produce flower buds for the next season. Remove shoots that have bloomed. Do not cut into woody trunks.

Group B: Large-flowering Hybrids
These bloom in mid-June on short stems from the previous season's growth and often again in late summer on new growth. Prune in March by removing dead and weak stems, then cut back remaining stems to the topmost pair of large, plump green buds. This cut could be a few inches to a foot or two from the stem tips. Prune slowly from the top until you reach a good bud, one stem at a time.

Group C: Late-flowering Clematis
Plants in this group flower on the last two to three feet of the current season's growth. In March, cut each stem to a height of about 2-3 feet. This will include removal of some good stems and buds but don't worry, they'll grow back!

Watering
Clematis need water, but not too much. Feel the soil between waterings. Plant that are too wet can be affected by crown rot. How often clematis need to be watered will depend on the weather.

Fertilizing
When planting clematis, fertilize with Plant-tone according to label directions. After the vine is established, use fertilizer recommended for flowering plants, Plant-tone is recommended.

Clematis Wilt

The most devastating disease of Clematis is fungal stem rot and leaf spot commonly known as wilt. Symptoms include a sudden stem collapse typically as the flower buds are about to open, and within a few days, the stems and leaves turn brown or black. Only one or perhaps a few stems may be infected by wilt.

The cause of Clematis wilt is unknown but the most common theory is that it is caused by a fungus. The fungus can attack only one shoot, leaving the rest of the plant healthy, including the root system.

Wilt usually affects large flowering hybrids. We have noticed that wilt is not so prevalent in the fall blooming type, Clematis paniculata or terniflora.

The usual treatment is to remove the diseased stem(s) below the wilted section, even below the soil line. Plants will usually recover from buds present on the lower stem.

Growing Tips

Choose a favorable planting site. Your site should receive about 6 hours of sun or more per day and be well-drained with a neutral pH.
Select resistant plants. Small-flowered hybrids seem to be more resistant than large-flowering forms.
Keep the area around your Clematis free of debris all year round.
Take special care to avoid injury to the stem and roots
Do not cultivate near the roots of Clematis
Mulch the root system as they like to have their roots shaded.
Remove diseased stems immediately. In the event that the plant becomes infected, cut the diseased stems just below ground level and destroy them.