How-To

What’s Causing Clematis Leaves Turn Brown

Clematis leaves turn brown every year for a number of reasons. This is called leaf scorch and can affect some varieties of clematis more than others. Here are the causes, best prevention, and possible treatment options to revive scorched clematis leaves.

Causes of leaf browning

Clematis leaf browning is a common problem in many types of clematis plants. The cause may be too much water, lack of water, too much sun or shade, poor soil conditions, or damage from insects such as aphids or thrips.

Poor soil conditions

A common cause for foliage damage is poor soil conditions that lead to nutrient deficiencies or imbalances. This is especially true in established plants where the roots have already become established in a particular area and may not be able to move around in search of new nutrients. Some examples of poor soil conditions that can cause the leaves of clematis to turn brown include:

Poor drainage

One reason for poor drainage is compacted soil. Compacted soil does not allow water to drain freely through it and may result in root rot. Soil compaction also makes it difficult for plants to obtain nutrients and water from the soil, leading to nutrient deficiencies and wilting.

Excess nitrogen

Excess nitrogen is one cause of browning leaves. Nitrogen promotes lush growth and causes leaves to turn yellow or brown as they age. Excess water and fertilizers can cause nitrogen toxicity in clematis plants. If you use a fertilizer that contains more nitrogen than your plant needs, you may need to reduce the amount or change the type of fertilizer you use.

Too much sun

Clematis plants are native to wooded areas where there is plenty of shade. They do not like direct sunlight. If you want to grow them in full sun, choose a dwarf variety that is suited to full sun or give your plant some protection from the sun’s hot rays with a shade cloth or other covering. If your plant is getting too much sun and turning brown, it may be time to move it into a shadier spot where there will be less stress on the plant’s leaves.

A lot of shade

Clematis can grow in full sun or partial shade, but they do best in an area that gets at least six hours of sunlight each day. If your clematis is planted in an area that gets less than five hours of direct sunlight each day, its leaves will begin to turn brown as it attempts to protect itself from the lack of light by withdrawing nutrients from its foliage.

Fungal diseases such as downy mildew

Downy mildew is a fungal disease that causes pale green or yellowish-green spots on the leaf surface. These spots eventually turn brown and necrotic (dead). The disease may also appear on clematis plants’ stems, flowers, and fruits. Downy mildew is most severe in hot, humid weather conditions such as those in southern climates during the early summer months.

Insect damage

Several types of insects feed on Clematis foliage and can cause spots or holes in leaves. These include:

Whiteflies – Whiteflies are small insects that suck sap from plant leaves and stems, which can cause yellowing, wilting, or leaf drop. These pests also produce honeydew, which can encourage sooty mold growth on the leaves of some plants. The best way to control whiteflies is by using insecticidal soap spray or neem oil applied to the tops of the plants.

Spider mites – Spider mites are another common pest affecting clematis vines. They cause foliage damage by sucking sap from leaves, causing stippling or speckling on their surfaces, and webbing between leaves and stems. Spider mite infestations can be treated with insecticidal soap spray, or horticultural oil applied directly to the affected areas.

Hornworms – These pests feed on the leaves and stems of Clematis plants. They make holes in leaves and eat out their insides, causing them to turn brown or black. Their feeding also causes stems to turn black and die back on some varieties such as ‘Blue Elf.’

Leaf miners – These larvae feed inside leaves, making tunnels that cause dark streaks or blotches on leaves before they emerge as adult moths through small holes in leaves where they mate and lay eggs before dying off for winter.

Over-watering

Clematis plants are susceptible to root rot if they receive too much water. If the roots are submerged in water for extended periods of time, they can die, causing the plant to wilt and die. If you have noticed your clematis wilting, check to see if there is standing water on the leaves or at the base of the plant. Another sign that your clematis may be overwatered is if it has brown spots on its leaves. These spots are caused by fungal diseases that thrive when too much moisture is present around the roots of the plant.

Winter damage

Winter damage is caused by changes in temperature that are too rapid for the plant to tolerate. The cold temperatures cause cells within the plant to freeze, which ruptures them and leads to cell death. In addition, ice crystals form within the cell walls, which also leads to cell death.

Winter damage can occur on any part of a plant (including stems), but it’s most commonly seen on leaves because these are usually at ground level, where they’re exposed to freezing temperatures from below as well as from above (when snow piles up against them).

Improper care

Improper watering, fertilizing, and pruning can damage the leaves of a Clematis.

Over-fertilization can also lead to the browning of the leaves of your Clematis. Too much nitrogen in the soil results in excessive leaf growth at the expense of flowers and fruit production. Pruning improperly can lead to the browning of leaves on your Clematis too. You should prune your plants only when they are dormant during winter.

How to prevent your Clematis leaves from being brown

To prevent brown leaves on clematis, follow these tips:

Water your clematis only when the soil is dry

The best way to keep your clematis looking its best is to water it only when the soil is dry. To test whether your plant needs water, stick your finger into the soil up to your first knuckle. If the soil is still damp underneath your finger, then you don’t need to water it yet. If there is no moisture left in the soil at all, then it’s time to give it a drink.

Keep your clematis away from stagnant water

To avoid bacterial and fungal growth in the soil, ensure the area around your clematis is well-drained. If your plant is growing in a pot or container, ensure the soil is free of any standing water after watering. Use mulch around the base of your plant to help prevent water stagnation from happening. Mulch also helps retain moisture in the soil around the base of your plant, so it doesn’t dry out so quickly.

Prune regularly

If your clematis gets infested by pests or diseases, it may start growing poorly or stop flowering altogether. Pruning regularly helps keep your plant healthy so that it can thrive and produce flowers instead of struggling to survive. Cut off any dead stems at the base so that new growth can emerge from healthy areas of the vine where there is no damage yet. You should prune your clematis every spring before its first blooms.

Fertilize clematis with a fertilizer that has low nitrogen

Nitrogen is needed to produce new growth, but too much of it will cause the plant’s roots to burn out and die. Fertilizer with low nitrogen provides just enough nutrients for healthy growth without causing damage to mature plants like those with mature root systems.

Check each plant for infected leaves or stems

Once your clematis shows signs of trouble, it’s important to recognize the signs and symptoms of plant disease so you can treat them quickly to avoid further damage. Here are some common diseases that can affect your clematis:

Botrytis blight — Caused by a fungus, this disease causes brown spots on leaves or stems. It spreads quickly through the plant and can infect other parts of the garden as well.

Anthracnose — This fungal infection causes dark spots on leaves and stems. It may also cause leaf drop and damage to flowers, so it’s important to treat this disease quickly before it gets out of hand.

Powdery mildew — This fungal disease causes white powdery spots on leaves and stems that can spread quickly across large areas of the plant if left untreated.

Look for fungal-resistant plants

The best way to prevent downy mildew is by planting resistant varieties of clematis. Examples of these varieties include:

Clematis ‘Jackmanii’ – The leaves of this clematis are a beautiful blue-green with creamy white veins. The flowers are very large, about 7″ across, and have a soft pink color with white centers. This is a vigorous grower with an upright habit. It will grow up to 10′ in height and width in one season. This variety is resistant to Powdery Mildew.

Clematis ‘Jeanne Lajoie’ – This is a unique variety with large, pale lavender flowers that are shaped like bells and have yellow centers. They appear in mid-summer on stems 6-8 feet tall and wide. This variety is resistant to Powdery Mildew.

Clematis ‘Lady Jane’ – A vigorous plant that grows up to 10 feet tall by 5 feet wide each year. The flowers are white with purple spots on the upper petal, which gives them an unusual look compared to other varieties that have all-white blooms, although they tend to be smaller than other Clematis species. This plant is resistant to Powdery Mildew and Spider Mites.

Fungicides

If you do not have a resistant variety of clematis available in your area, fungicides can be applied according to label directions at the first sign of disease symptoms appearing on your plants’ leaves or stems.

How to use Fungicide on clematis plants?

To prevent fungus, apply a fungicide to the plant and the soil. Fungicides are available at most garden centers and hardware stores. When using fungicides on clematis plants, follow these steps:

  • Spray the leaves and stems of clematis plants with a fungicide containing benomyl or thiophanate methyl, according to label instructions.
  • Apply the fungicide early in the morning or late evening when temperatures are cool and humidity low (between 60 degrees Fahrenheit and 65 percent).
  • Water well after applying the fungicide so that it penetrates deep into the soil around your plant’s roots.

Natural remedies to deal with insects and fungus on your clematis plants

If you’re looking for some natural remedies to deal with insects and fungus on your clematis plants, here are some ideas:

Garlic insecticide spray

This is a great solution for controlling aphids, spider mites, scale, and whiteflies. This spray works best when applied early in the morning or late evening to avoid damage to the blooms. The garlic smell will dissipate within a few hours.

Garlic is an effective natural pesticide because it contains sulfur compounds that are toxic to insects. Garlic spray is easy to make and inexpensive. Simply chop up five garlic cloves into small pieces and add them to one quart of water in a jar. Let it sit overnight and strain out the solids before spraying on your clematis plants.

Neem oil insecticide spray

Neem oil is another effective way to control insects on your clematis plants. Neem oil kills insects by disrupting their hormones, preventing them from maturing into adults and reproducing further generations of pests. It’s also safe for humans, pets, birds, and fish, so you can use it around your home without worrying about harming other creatures nearby.

Insecticidal soap spray

Insecticidal soap spray is a good option to control pests on your clematis plants. The soap kills the bugs by disrupting their cell membranes, causing them to leak and eventually die. You can use this solution when you have an isolated infestation on one plant or if you’re trying to prevent future problems.

Apply the insecticidal soap as soon as you notice insects on your clematis plants. Spray the stems and leaves with a fine mist until they’re thoroughly soaked. If a heavy infestation is present, repeat the process every seven days for two weeks or until no new insects appear.

Garden lime insecticide

Garden lime insecticide contains potassium salts that burn through insect exoskeletons and kill the bugs quickly. This product works well against aphids, mites, whiteflies, and other small pests that feed on the leaves of clematis plants. Garden lime should not be used on any plants other than clematis because it’s toxic to many types of vegetation.

Clematis leaves turning brown is a common problem that can ruin all the summer and fall months when the plant is looking its best. The culprit is almost always too little water during periods of hot, dry weather. Overwatering and underwatering are common reasons this happens. If conditions start getting too hot, it might be a good idea to check your clematis for signs of brown leaves so you can correct the watering habits before it’s too late.