Star jasmine (Trachelospermum jasminoides) Flower, Leaf, Care, Uses - PictureThis (2024)

Water

Every week

Sunlight

Partial sun

Hardiness Zones

Planting Time

Spring, Fall

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Discolored spots on the foliage of plants are one of the most common disease problems people observe. These spots are caused by fungal and bacterial diseases, with most infections related to a fungal pathogen.

Brown spot can occurs on all houseplants, flowering ornamentals, vegetable plants, and leaves of trees, bushes, and shrubs. No plants are resistant to it, and the problem is worse in warm, wet environments. It can occur at any point in the life stage as long as leaves are present.

Small brownish spots appear on the foliage and enlarge as the disease progresses. In severe cases, the plant or tree is weakened when the lesions interrupt photosynthesis or cause defoliation.

In most cases, brown spot only affects a small percentage of the whole plant, appearing on a small amount of the leaves. A small infection only puts minor stress on the plant. However, if left untreated and the disease progresses over numerous seasons, it will severely impact the health and productivity of the infected specimen.

• Sporulation begins (reproduction of the fungal spores), and tiny spots appear on leaves.
• Placement is often random and scattered as diseases are spread through raindrops.
• May appear on lower leaves and the interior of the plant where humidity is higher.
• Brown spots enlarge and grow large enough to touch neighboring spots to form a more prominent blotch.
• Leaf margins may turn yellow.
• Tiny black dots (fruiting bodies of the fungi) appear in the dead spots.
• Blotches grow in size until the entire leaf is brown.
• The leaf falls off the plant.

Severe Symptoms

• Partial or complete premature defoliation
• Reduced growth
• Increased susceptibility to pests and other diseases

Brown spot, or leaf spot, is a common descriptive term given to several diseases affecting the leaves of plants and trees. Around 85% of diseases exhibiting leaf spots are due to fungus or fungus-like organisms. Sometimes brown spot is caused by a bacterial infection, or insect activity with similar symptoms.

When conditions are warm and the leaf surfaces are wet, fungal spores being transported by wind or rain land on the surface and cling to it. They do not rupture the cell walls but grow in the space between the plant plasma membrane and the plant cell wall. As the spores reproduce, they release toxins and enzymes that cause necrotic spots (i.e., dead tissue) on the leaves, allowing the fungi to consume the products released when the cells degrade.

In minor cases of brown spot, there isn’t any need to treat the disease. However, if much of the foliage is affected and defoliation occurs, the plant will benefit from getting rid of the infection. It is recommended to start by applying organic treatment options, working up to the more potent synthetic, chemical fungicides if necessary.

Organic options won’t kill the fungus, but will prevent it from spreading.

1. Dissolve ½ teaspoon of baking soda and one teaspoon of liquid soap in a gallon of water. Using a spray bottle, spray on tops and bottoms of leaves until the mixture drips off. Repeat every two weeks until existing spots stop enlarging and new spots no longer appear.
2. Spray a copper-based fungicidal soap on the leaves, coating the top and bottom leaf surfaces. Reapply as directed on the product label. Copper penetrates the leaf surface and prevents germination of spores so the fungus cannot spread.
3. Apply an all-purpose fungicide to the entire plant, following the label instructions carefully.

Like many other diseases, it is easier to prevent brown spot than cure it, and this is done through cultural practices.

• Clear fall leaves from the ground before winter to minimize places where fungi and bacteria can overwinter.
• Maintain good air movement between plants through proper plant spacing.
• Increase air circulation through the center of plants through pruning.
• Thoroughly clean all pruning tools after working with diseased plants.
• Never dispose of disease plant material in a compost pile.
• Avoid overhead watering to keep moisture off of the foliage.
• Keep plants healthy by providing adequate sunlight, water, and fertilizer.

Flower withering occurs when flowers become weak, droopy, wilted, or faded until they can’t be revived. During withering, they begin to wrinkle and shrink until the flower becomes completely dry or dead.

Any flowers, regardless of the plant type or the climate they are grown in, are susceptible to withering. It is a worldwide problem across houseplants, herbs, flowering ornamentals, trees, shrubs, garden vegetables, and food crops.

Unlike wilting—which withering is often confused with—withering can be caused by different things and is often due to more than a lack of water. Withering can be fatal in severe cases.

Flower withering progresses from very mild cases to severe occurrences that kill the flower. The severity of the symptoms is related to the cause and how long the condition is allowed to progress before action is taken.

• Wilted, droopy flowers
• Petals and leaves begin to wrinkle
• Brown papery streaks or spots appear on the petals and leaf tips
• Flowerhead shrink in size
• Petal color fades
• Yellowing leaves
• Complete death of the flower

The main causes of flower withering include natural age progress, lack of water, nutritional deficiencies, and bacterial or fungal diseases. It’s critical to determine the underlying cause when flower withering is noticed. This will guide the best course of action, if treatment is possible.

Check the soil for moisture and then closely examine the entire plant for signs of nutrient deficiencies. If neither of those appears to be the cause then cut open the stem below a flower. If a cross-section reveals brown or rust-colored stains it is safe to assume that this is a bacterial or fungal infection.

If the flower is nearing the end of its normal lifespan, genetic coding within the plant increases the production of ethylene, a phytohormone that controls senescence, or cell aging and death. Cell division stops and the plant begins breaking down resources within the flower to use in other parts of the plant.

In all other cases, flower withering happens when the plant seals off the stem as a defense mechanism, stopping transport within the vascular system. This prevents further water loss through the flowers but also stops bacteria and fungi from moving to healthy parts of the plant. Once water and nutrient transport stops, the flower begins to wither and ultimately die.

If flower withering is a natural progression due to age, there is nothing that can be done to slow or stop the process. Once hormones within the plant begin the process of senescence, it’s irreversible.

For lack of water, immediately water the plant using room temperature rainwater, bottled spring water, or filtered tap water. Water container plants until excess water drains out the bottom; water in-ground plants until the soil is soaked but there isn’t standing water on the surface.

In the event of nutritional deficiencies, the best solution is to use a granular or water-soluble liquid fertilizer, and apply it to the soil at about half the recommended dosage. Keep it off the leaves and make sure granular products are watered into the soil well.

If the plant is infected with a bacterial or fungal pathogen, there is no course of treatment that cures the diseased plants. The best solution is to remove the infected plants and dispose of the plant material off-site. Do not put in a compost pile.

This is definitely one of those instances where prevention is more effective than cure. Here are some preventative measures for avoiding premature flower withering.

• Water plants according to their needs -- either keep the soil slightly moist or allow the top inch or two to dry out before watering again.
• Fertilize lightly on a consistent basis, depending upon the plant’s growth. Quick-growing plants and those that flower or develop fruit will need more frequent fertilizing than slow-growing plants.
• Purchase plants that are certified disease- or pathogen-free.
• Look for disease-resistant cultivars.
• Isolate plants showing disease symptoms to prevent the spread to neighboring plants.
• Practice good plant hygiene by removing any fallen plant material as soon as possible.

Nutrient deficiencies can be seen in many different ways on plants. Basically, the lack of nutrients will inhibit plant growth, produce weak stems and leaves, and leave plants open to infection from pests and diseases. Plants use the nutrients from the soil to help them with photosynthesis. This, in turn, produces healthy plant growth. Plants that lack adequate amounts of nutrients will look lackluster and unhealthy. Eventually, if this is not addressed, it will cause the plants to die. The most important nutrients that plants need are nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. Additionally, plants require small amounts of micronutrients such as iron, boron, manganese, zinc, copper, and molybdenum.

A common sign that plants are experiencing nutrient deficiencies is the yellowing of leaves. This may be an overall yellowing or leaves that are yellow but still have green veins. These leaves will eventually brown off and die.

Another sign is the loss of plant vigor. The plants may not be growing as well as they should or their growth may be stunted.

Below are some common symptoms that appear when plants are lacking in nutrients.

Nitrogen (N): Inner, older leaves yellow first. If the deficiency is severe, yellowing progresses outward to newer growth.

Potassium (K): Leaf edges may turn brown and crinkly, with a yellowing layer forming just inside of the edge. Older leaves tend to be impacted first.

Phosphorus (P): Lack of vigorous growth. Plants will appear stunted.

Zinc (Zn): Yellowing tends to occur first at the base of the leaf.

Copper (Cu): Newer leaves begin to yellow first, with older leaves yellowing only if the deficiency becomes severe.

Boron (B): Newer leaves are impacted first. Foliage may also become particularly brittle in cases of boron deficiency.

There are several factors that can lead to nutrient deficiencies, a situation where plants are not receiving the nutrients that they need. This could be because they are planted in nutrient-deficient soils, or that the soil's pH is too high or low. Incorrect soil pH can lock up certain nutrients, thus making them unavailable to plants. Lack of soil moisture can also be a problem, because plants need water to be able to absorb the nutrients from the soil.

There are several easy ways to remedy the nutrient deficiencies in soils.

1. Use a water-soluble fertilizer. Fertilizers will include most or all of the macro and micro-nutrients the plants need to thrive. Adding some fertilizer to the soil will make those nutrients available and can combat deficiencies.
2. Regularly apply organic fertilizer pellets. Organic fertilizers such as animal manures and bonemeal can supply plants with all the nutrients that they need to grow strong and healthy.
3. Apply compost. Though not as finely tuned as artificial fertilizer, compost can nevertheless be rich in important nutrients and should be applied to the soil regularly.
4. Apply nutrients via foliar application. In addition to supplementing the soil with nutrients, foliar fertilizer can be applied directly to the plant's leaves. Nutrients offered via foliar application are often taken up even quicker than those put in the soil, so the foliar application can be great for swiftly addressing specific deficiencies.

There are several easy ways to prevent nutrient deficiencies in plants.

1. Regular fertilizing. Regular addition of fertilizer to the soil is one of the simplest and most effective ways to prevent deficiencies.
2. Proper watering. Both over and under watering can adversely impact a plant's roots, which in turn makes it harder for them to properly take up nutrients.
3. Testing the soil's pH. A soil's acidity or alkalinity will impact the degree to which certain nutrients are available to be taken up by plants. Knowing the soil's pH means it can be amended to suit the needs of the individual plants.

Petal blight, sometimes called flower blight, is a fungal disease that only affects the blooms of some ornamental flowering plants. As the infection progresses, it destroys the flower, yet it never damages the vegetative or green parts of the plant.

When flowers are infected, the symptoms look similar to Botrytis blight, but Botrytis also infects dead or dormant vegetative tissue.

The disease was first discovered in Japanese plants in 1919 and in the US in the late 1930s. Presently it is also found in New Zealand, Australia, and parts of Europe. Unfortunately, no plants have high resistance to petal blight, but specific cultivars are more susceptible than others, particularly species with double blooms.

Petal blight infection rates are high when temperatures are mild to warm (optimum temperatures are 15 - 21 ℃) and the weather is misty or rainy.

Overall, petal blight is an aesthetic problem that ruins blossoms. The disease is not harmful to the long-term health of the plant.

The severity of the symptoms varies, depending upon the species of plant infected. Signs of petal blight are commonly seen on the blooms just after they open.

• Pallid spots on colored petals.
• Brown spots on white petals.
• Browning around the petal edges.
• Small spots look water-soaked.
• Spots rapidly enlarge and merge.
• Flowers become limp.
• The entire flower turns light brown, but does not crumble.
• Flowers become slimy at first and then take on a leathery texture.
• A ring of white or gray mycelium can be seen at the base of the petals.

Petal blight is caused by several different fungi, with each type infecting specific plants. Ovulinia azalea infects azaleas species and cultivars, and rhododendrons. Ciborinia camelliae infects camellia cultivars.

Shortly after blooming, the fungus infects the base of the flowers by the calyx. The fungus produces cell wall-degrading enzymes that destroy flowers within a couple of days. When the flowers fall to the ground, the fungus' hard fruiting bodies fall to the soil as well, overwintering until the following spring.

When temperatures hit the optimum range the following season, spores are transmitted by insects or can spread on wind currents up to about 12 miles. Once in the soil, the pathogen can be active for three to five years.

Like other fungal diseases, the progression of petal blight is extremely difficult to stop and impossible to reverse once it infects a plant. The best course of action is to remove all damaged flowers immediately and dispose of them entirely. Do not put them in the compost pile, where spores could grow and spread.

• Apply a preventative dose of fungicide as soon as blooms start to show color on the plant. The preventative can be applied as a soil drench or directly to the flowers on the plant.
• Avoid overhead watering during blooming.
• Remove any leaf litter and dead flowers at the end of the season.
• Cover the ground under infected plants with 4” of fresh organic mulch before winter, taking care not to disturb the infected soil.
• Buy bare-root specimens when available.
• When potted plants are purchased, remove the top layer of potting soil and replace it with fresh mulch.
• Plant cultivars that bloom early in the season before the temperatures get high enough for petal blight pathogens to be spreading.

Leaf Weevils are insects that feed on the leaves of plants. They can cause major damage to both edible and non-edible plants. Watch out for these garden pests and use control measures to get rid of them as soon as the problem is noticed.

Leaf Weevils are small flightless insects that are typically around 6 mm long. They have a hard body that is oval shaped and covered in short hairs, a long snout on their head that is downward facing, and 3 pairs of legs with hooked claws.

Once mated, the female weevil with lay around 20 eggs at one time, either in leaf litter on the ground or sometimes on the soil. Weevils generally only produce one batch of eggs a year but may produce 2 if conditions are ideal.

The eggs take around 6 to 15 days to hatch. When the larva emerges, it burrows into the soil. These larvae have chewing mouth parts and no legs. They feed on the roots of the plants. When this happens, you may see signs of wilting of the leaves, stems, and flowers as the plant can’t deliver enough water from the roots to the above-ground growing parts.

Eventually, the larva evolves into a soft white pupa. The pupating period normally takes around 1 to 3 weeks. After this, the adult leaf weevil will emerge and crawl up the plant to feed on the leaves.

Adult leaf Weevils feed on young leaves, stems, flowers, and buds of almost any plant. This includes many varieties of fruits and vegetables as well as ornamental plants. This creates irregular round holes in the leaves. These holes normally start at the edges of the leaf. Holes may also be made in flowers, lesions may be caused on the skin of fruit, and sometimes whole stems are chewed off.

These insects prefer a humid environment with warm temperatures. They are mostly active during the night and will hide in leaf litter, mulch, and other debris during the day.

Leaf Weevils are relatively easy to control once their presence is discovered. Here’s what to do:

• Spray the foliage with an insecticide
• Place sticky traps around the lower trunks of fruit trees and other woody plants. Weevils can’t fly, and have to crawl up the plants when they emerge from the soil.
• Dig into the soil around plants with a garden fork and remove and dispose of any larvae.
• Let chickens roam around the garden, as they love to feed on weevil larvae.

There are various ways to keep leaf Weevils away from plants.

• Remove weeds such as dandelion, capeweed, portulaca, mallow, sorrel, and dock. Leaf Weevils are attracted to these weeds and will set up a colony.
• Make sure fruit trees are well spaced from each other. This ensures that the weevils and their larvae don’t spread from one tree to the next.
• Cultivate the soil before planting a new crop. This allows any larvae or pupae in the soil to be unearthed and disposed of.
• Regularly fertilize the soil to encourage both earthworm and microbial activity.
• Check plants regularly to see any signs of leaf weevil activity. Also check under loose bark, mulch, leaf litter, and in the junction of stems on the plant.