Most gardeners put a lot of time and love into their plants. But even if optimal conditions are provided, the plants in the garden can be infested with diseases or pests. Unfortunately, clematis, especially the large-flowered species with their beautiful and colorful flowers, are sometimes attacked by wilt fungi. Clematis wilt is one of the dreaded fungal diseases that cause the vines to die off completely in a short time. We have put together the most important rules for the prevention and control of clematis wilt for you.
Table of Contents
Delicate climbing plants
Clematis, also known as clematis, occur in around 300 different species, mainly in the temperate zones. In gardens, hybrids are predominantly used, which have particularly numerous, large and colorful flowers. They grow up on neighboring plants or other supports such as trellises and green fences, hedges, house walls and rose arches. The stems can hardly be loosened once they have grasped the hold. However, this framework must be very firmly anchored. A thin stick alone is not enough, because if the clematis does not have enough support, the shoots snap off quickly when it is windy. Then the clematis wilt has an easy job. Because the spores of the fungi, which are responsible for the wilt, are already waiting in the ground to penetrate into injured parts of the plant.
Very few people know that the clematis wilt is basically two different diseases, which also have a different course of disease:
- Phoma-Which
- Fusarium-Which
Phoma-Which
Most often the clematis is attacked by the Phoma clematis wilt. The first signs of an infestation with the fungal pathogen (Ascochyta clematidina) can be seen on the plant in May or June: Small, yellowish-brown spots appear on the older leaves close to the ground, which spread quickly. Initially still round, the spots become misshapen and darker as the disease progresses. Eventually they spread all over the leaf, which then dies. However, the fungus does not remain on the leaves – as in the harmless leaf blotch disease – but also spreads in the stems and shoots. In general, all types of clematis can be attacked, but as a rule only the large-flowered hybrids show complete destruction of the plant above ground.
Fight
It is crucial to save the plant that the infestation is detected early. The older leaves in the lower third of the clematis are always affected first. Therefore, all clematis in the garden should be checked for leaf spots at regular intervals from mid-May. The intervals must not be too far apart, because entire shoots can die off within two weeks.
- Remove dead leaves and shoots.
- Dispose of with residual waste.
- Do not throw on the compost (uncontrolled spread!)
- Spray with a commercially available fungicide.
If the fungus has not yet passed through the pathways to the shoots or the whole plant, the plant usually recovers quickly. If it is detected too late, the clematis can usually no longer be saved despite fungicide treatment, as the fungus has already reached the inside of the shoot and can no longer be fought there.
Since the fungus does not penetrate into the root area, the clematis may survive despite the complete death of the upper parts of the plant and sprout again after two to three years. So there is no need to dig up the roots. Those who give their clematis a little time can sometimes experience a positive surprise after a while.
Prevent
The dead shoots and the fallen leaves of the infected clematis are infected with the fungus and can infect other plants in the garden at any time if they come into contact. Therefore, it is imperative to ensure embarrassing hygiene.
- Keep any fallen leaves.
- Also the dried up leaves from the previous year.
- Dispose of together with household waste.
- Thoroughly disinfect the tool used with hot water or alcohol.
Plants are only infected when they are moist. Therefore, the clematis should have a place protected from the rain, where the air can circulate well.
Fusarium-Which
This less common clematis wilt, the so-called fusiarosis, is caused by a slime mold called Coniothyrium clematidis-rectae. This penetrates the wood from the outside through injuries in the tissue of the plants. There it spreads through the supply control systems in the plant and causes blockages so that the upper parts of the plant can no longer be adequately supplied with water and nutrients. Large-flowered species and young plants are particularly often affected. Every clematis can in principle get sick. If the plant is strong and healthy, it is usually better protected. Old or weak clematis canes are particularly often the first to be infected. Damage to the young shoots as well as to the base of the stem also favor an infestation. These can be caused by strong winds,
In contrast to the Phoma wilt, all the leaves and shoots above the damaged area wither suddenly with the fusiarose. In addition, they do not discolor point-like, but begin with a brown edge that spreads towards the center of the leaf. Since the fungus needs relatively high temperatures (20-30 degrees), the first signs of Fusarium wilt rarely appear before mid-June.
Fight
If from June individual shoots of the clematis suddenly die off for no apparent reason, the Fusarium clematis wilt is probably to blame. Acting quickly is now important:
- Immediately cut off all shoots close to the ground.
- Collect all fallen leaves (also from the previous year).
- Put in a plastic bag and dispose of with household waste.
- Never throw on the compost (risk of infection of other plants).
- Disinfect cutting tools after use.
- Fungicides are ineffective on Fusarium wilt.
If the Fusarium wilt is detected early and the gardener acts quickly, the chances are good that the clematis will recover after a while. As with the Phoma wilt, the fungus does not penetrate the root area, but only affects the shoots and leaves.
Prevent
Of course, hardy species can be selected from the start. But that’s not the only way to reduce the risk of infestation. The right protection starts with the purchase: a strong plant in a 2 to 3 liter container has already passed its critical period.
As a preventive measure against the Fusarium clematis wilt, the selection of the right location and a good preparation of the soil when planting are important. Plants that are in unprotected or damp areas in the garden are usually affected by wilt. Plants weakened by unfavorable conditions are significantly more susceptible than healthy, vigorous specimens.
location
- protected from rain
- sheltered from the wind
- protected from strong temperature fluctuations (cold winds, midday sun)
- The best locations are where the morning or evening sun shines for a few hours.
- Attach a shading net in very sunny locations.
- Install a trellis at a sufficient distance from the house wall.
Soil / plants
- Thoroughly loosen the soil before planting.
- Remove all old roots from neighboring plants.
- If necessary, provide drainage from sand or gravel.
- Dig a rhizome barrier or an old board in the root area (against root competition from neighboring plants).
- The pot in which the clematis was bought can also be used. Then carefully cut out the bottom of the pot.
- Enrich the soil with plenty of deciduous humus or ripe compost (about two spades deep).
- Plant at a slight angle and two pairs of eyes deeper than in the pot.
- Suppress weed growth by applying bark mulch.
Care / care errors
- Never rake the soil under the clematis (damage to the roots or shoots possible).
- Avoid all damage to the shoots (this is where the fungus can attack).
- Waterlogging weakens the plant (in extreme cases, root rot).
- Water only in the root area, but not over the leaves.
- It is essential to observe the cutting rules.
- It is essential to fertilize and water young plants regularly in the first two years.
Clematis like it cool in the root area. At their natural location on the edge of the forest in the shade of the trees, they first have to fight for their sunlight. So it’s no wonder if the full sun around the roots (especially in a heated bucket) does not please them.
Insensitive species
If you want to protect yourself, you should prefer to use original species such as the Italian clematis (Clematis viticella) when buying a clematis.
- Prince Charles: delicate light blue, sometimes light pink
- Etoile Violette: velvety violet
- Betty Corning: light blue bells
- Alba Luxurians: White
But there are also a few large-flowered hybrids that are not very susceptible:
- General Sikorski: medium blue with purple stripes (spring bloomer)
- Pink Champagne: intense pink (spring bloomer)
- Niobe: dark velvet red (spring bloomer)
- Gypsy Queen: dark purple (summer bloomer)
- Hagley Hybrid: Light Pink (Summer Bloom)
- Jackmannii: Blue-violet (Summer Bloom)
- Viola: blue-violet to black (summer bloomers)
The small, tulip-shaped flowers of Clematis texensis are also very robust:
- Duchess of Albany: pink with light streaks
- Princess Diana: bright pink to salmon
Many golden yellow varieties of Clematis tangutica are very resistant:
- Helios: yellow, long flowering period
- Bill MacKenzie: yellow bells
Conclusion
The protection against the clematis wilt begins with the purchase of the plant. Look specifically for resistant species. Both types of clematis wilt often only occur when the plant is in an unfavorable location and is weakened. While plucking the leaves and treating with fungicides can be very effective in combating Phoma wilts, a more radical approach has to be taken with Fusarium wilts. If entire shoots suddenly die, the clematis should be cut off immediately near the ground. If you recognize the clematis wilt in good time, the plant can survive the fungal attack, even if it sometimes takes two years before it sprouts again.