Tips for Treating Black Spot on Roses

Roses are susceptible to three major diseases, and black spot is one of them. Fortunately for rose growers, it is also one of the easiest rose diseases to treat. Black spot is a fungal disease that most often appears during humid, rainy conditions and causes black patches on stems and leaves of rose plants.

Recognizing Black Spot
During humid, rainy conditions, gardeners should check roses one a week for this disease. The first sign of black spot on roses is small pinhead-sized spots on plant leaves. The spots gradually grow larger and becomes surrounded by a halo of yellow dying leaf tissue. As the disease progresses, rose leaves turn yellow and drop. The good news is, treatments for black spot generally work even in advanced stages of the disease.

Black spot spreads by fungal spores that travel through the air and on surfaces that have come into with infect leaves, such as gardening tools. Fungal spores can also spread by water spray and dead leaves that have fallen and landed on the soil under the plant. Black spot fungal spores are able to survive in the soil during winter.

Treating Black Spot
Treatment for black spot is an ongoing process that includes early prevention, prompt treatment and regular treatments to prevent recurring infections. Early prevention includes monitoring roses as soon as new growth appears and spraying roses with a solution of one part lime to nine parts wettable sulfur during winter.

Ongoing treatment includes removing any infected rose leaves and disposing of them as soon as possible. Once black spot sets in and begins to progress, gardeners need to begin a regular weekly application of a suitable fungicide, such as Daconil or Benomyl .

Other Tips
Good watering practices can help reduce the risk of black spot. Soaker hoses are ideal for roses that are susceptible to the fungal disease. These hoses are placed around the plant's base to prevent water from splashing up onto plants.

When spraying roses with a fungicide, gardeners must follow label directions, as these will advise them on how to safely apply the product to the plants and which plants may be sensitive to the active ingredients in certain products.

If black spot becomes a recurrent problem on one or more of the rose bushes in the garden, cut the entire plant low to ground in the fall, removing any stems that have been affected or could be carriers for black spot fungal spores.

Healthy plants are better able to withstand black spot infections. To ensure healthy roses, buy healthy plants from a reputable nursery, position plants in the garden to ensure they receive adequate air circulation and water carefully near the plant roots and early in the day. Prune roses as needed to remove an dead or diseased limbs and immediately pick up and discard any leaves that have fallen off the plant onto the soil below. When pruning roses, always use sharp clean pruners, and if they come into contact with black spot fungus, wash them in a bleach solution.

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How to Identify and Prevent Common Vegetable Plant Diseases

Plants are vulnerable to many diseases. These diseases are mostly caused by fungi and viruses. There are also a few bacterial infections that attack plants and produce similar symptoms to those of fungi. Their is a long list of ways plant diseases can sneak into a garden and attack the plants. They can already be present in the seeds you sow. They could be in the soil around the roots of a plant, or carried in the soil on the soles of your shoes. They may also come in on new plants or plant material from the nursery or garden store where you purchased them. They can even arrive in the garden on a wind. Here is a list of some very common plant disease, what they infect, symptoms and how to prevent and control them.

MILDEW: This affects peas, onions, lettuce, spinach and cabbage. The powdery and downy mildew produce a white or gray mold, it is often found in round patches. Downey mildew appears on the undersides of leaves in cool, damp conditions. Powdery mildew forms on the top in dry conditions. To prevent this disease do not overcrowd plants or over water them. Look for mildew resistant varieties. Remove any plant debris promptly. To chemically control them you will use green and yellow sulfur for powdery mildew and for down mildew you will use the chemical mancozeb.

BLIGHT: This disease affects potatoes and tomatoes. Blight favors warm,wet weather. It progresses rapidly on potatoes. The first signs are dark blotches on the leaves, followed by rapid wilting and yellowing of the foliage and stems. Then the plant will usually collapse in a few days. Blight is less dramatic on tomatoes, but is still serious. The leaves start collapsing and the fruit develop brown rotting patches. A different organism is responsible for early blight, which causes brown spots on the leaves it is much less serious. Warnings are often given when the right combination of humidity and temperature are present. To prevent further damage when you spot the disease on potato foliage remove and burn the top growth. If you harvest the crop right away the tubers may be unaffected. Destroy infected crop remains by burning them. Planting tomatoes in greenhouse are less likely to be attacked by this disease. There are a few different types of chemicals you can use on this disease they are mancozeb, copper sulfate and copper oxychloride.

BOTRYTIS (GRAY MOLD): This disease affects many different crops, especially lettuce and tomatoes. It produces a fluffy gray mold growth, under this growth the plant tissue rots. This fungus starts on dead tissue but spreads quickly to live parts. It is found quite often in greenhouses. It prefers cool, damp places. To help prevent this disease keep greenhouses well ventilated. Make sure your plants are not overcrowded, water early in the day and do not splash water. When you spot any of this disease clear all the dead and dying plant debris away.Cut out and destroy any affected parts.

WILT: This disease affects tomato and cabbage family. Fusarium wilt is the most common type. Young plants become pale and stunted, lower leaves yellow and wilt. The symptoms move upward and plants may die. Verticillium wilt causes similar symptoms but without one-sided effects. Wilt diseases are worse in the hot weather. To prevent this disease grow only disease resistant plants. Clear away any infected plant debris and rotate crops. Their are no chemicals to use on this disease.

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Insects on Houseplants

Recognizing, Treating and Preventing Insects on Houseplants

I am an Horticulturist and for 36 years I worked in interior tropical greenhouses. I specialized in interior tropical plants; houseplants. Many of my houseplants are gems I grew form small cuttings that have developed into large, lush specimens. Even though my home does not have a great amount of natural light, I selected the types of plants that would grow well in the amount of light I can provide for them. I have many plants in my home and have put them in groups of gardens in different rooms where the light levels are the highest. These gardens are groupings of plants that take the same light levels and the same water requirements. The plants are in decorative pottery that enhances the color of the leaves of each plant as well as the color schemes of the individual rooms. They are a focal point upon entering the room.

Of all the web sites I visited in reference to houseplant insects, I have not yet found one that gives a thorough description of how to get rid of insects once and for all, or how to prevent them in the first place. These next few articles in this series will list all the methods I use to keep my plants healthy and insect free-or at least how I keep insects at bay. Keeping them totally insect free is next to impossible. The bugs are out there and they will get to your plants at one time or another. That is nature's way. I will help you to learn how to identify them and what to do when you see them on your plants. The articles will be in the order that my experiences find those infestations hardest to destroy with least harm to the plants.

As I was learning about plant maintenance throughout the years, I learned the importance of clustering like plants together to increase the humidity around the grouping, as well as in the room. This clustering is great in providing humidity but it is also one way for insects to spread easily from one plant to another.

Those insects that affect houseplants have mouthparts that penetrate the surface of the plant and suck nutrients from it. The breathing holes are on either side of the body, allowing the bug to breath while it is feeding. Mealy bug is an insect covered with a white, sticky, waxy-like substance that protects the soft, brown body within. It allows water to run off the body, having no effect on the insect at all. The egg sacs are the cottony-like sacs found along vein lines on the top and bottom of leaves as well as in the crevices of leaf nodes and stems. The egg sacs can also develop around the root ball inside the pot. The egg sacs start out as tiny flecks of a dust-like substance that floats on air currents and is carried though the rooms in your home. These sacs will travel until they hit a surface and then will adhere to that surface until the time is right for the eggs inside to swell and grow. These sacs can remain on a rough surface, such as the underside of a shelf or window sill for up to ten years waiting until temperature and humidity are right for growth and development.

Once an egg hatches, the miniature adult climbs to the nearest plant and inserts its mouth parts into the plant surfaces and begins feeding. It will remain this way for as long as the nutrient flow provides enough for the insect's needs. The insects multiply rapidly and within a few weeks, an infestation can cover a plant. If left untreated, the infestation will kill the plant in time. As the females lay more egg sacs, they will accumulate and with any movement of the leaves by wind or other disturbance, they will float on the air currents to other areas. The adults can also crawl from one plant to another and when the plants are close to each other, the spread of the insects is that much easier. Mealy can fall in to your watering can and fall in to the soil of other plants with the water. If a pet happens to brush an infested plant, mealy can fall on its fur and travel to the next food source by hitching a ride.

One of the major signs of mealy on a plant is a sticky glaze that may cover one or several leaf surfaces. This is the secreation of the insects that falls from an infested leaf above. This honey dew may fall on the flooring or furniture beneith the plant and dissolves easily with warm water.

Of all the insects that infest houseplants, I consider the mealy bug to be the most difficult to get rid if entirely. The main reason is because of the egg sac's ability to remain dormant for so long and still be viable. The treatment for this insect takes time, dedication and persistence. To treat an infestation, you need to make a total commitment to your plant. If you do not, the insects will win every time--garanteed.

Meal bug is a type of soft-shelled scale. I will cover other scale insects in the next article. The waxy-like substance covering the body acts like a shield against moisture, either evaporating or penetrating. This makes using some substances ineffective in harming the body beneath. Because the shells are soft, it is easy to kill the insects by rubbing them with you fingers and squashing them. This is the most effect method of killing the bugs without harm to you or the plant. They cannot develop and effective immunity to this method, although it is a bit messy. This is also the only truly organic method of killing the insects. The other alternative is with the use of chemicals.

One of the best chemicals that has an instant effect on the insect is rubbing alcohol. It immediately dissolves the waxy covering exposing the body and it dies very quickly. This must hit the body to be effective and has no lingering power to affect any other adults or egg sacs. It only works for mealy bug and will not affect any of the other insects that attack houseplants. The alcohol evaporates very quickly so it does not harm the foliage unless it is used in too high a dosage. I often put the alcohol in a spray bottle and spray the foliage to the dripping point, trying not to saturate the soil or the delicate tips, as the alcohol can burn new foliage. Rinsing the leaves after spraying helps to minimize leaf burn on the older leaves.

Horticultural oil is also very effective in killing meal bug. The oil covers the mouth parts, causing the insect to suffocate. This is also an effective way to kill them as the insects cannot build up an immunity against suffocation. There is, however, no chemical that is totally safe and not-toxic. The whole point of the chemical is to kill, and the only safe part comes with using it according to the manufacture's recommendations. I have seen on too many occasions how the excess of these chemicals have killed the plant before it has affected the insect population.

Alcohol is effective and safe if you use it every couple of days rather than daily. For a really heavy infestation--one where the insect seems to be everywhere on the plant, you will need to us the three above methods to be even a little bit effective in getting rid of the problem. First, spray the horticultural oil on every part of the plant. You need to spray in an area where the residue will not harm pets or other people; a separate room or basement. Let the plant dry thoroughly before bringing it back to its place. Make sure you never use any insecticide when the plant is in sun as it will cause sever burning to the leaves.

This is the first step on day one. The second step is the next day to spray any egg sacs you find with alcohol. After the alcohol dries, you must use your fingers to eradicated any other individuals or sacs you find. Repeat this daily until day seven when you can spray with the chemical once again. You need to repeat this procedure daily, cleaning with the hands, using the rubbing alcohol, and spraying weekly with the insecticide until you do not find any new insects for two straight weeks. And, yes, this is a lot of work but if you are not diligent with the daily program, I can guarantee you will never get rid of the infestation completely. It will always come back after a bit.

But you must also clean the areas around the infected plants because the eggs can be on the shelves, curtains, windows, fixtures, or any other surface close to the plants. Be sure to remove all the plants from the area where they stay, and clean it well with a mild solution of warm soapy water. The sponge or cleaning rag is very effective in eradication of dormant egg sacs.

Many of my customers have mentioned using dish detergent as an insecticide. In all of my experiences with plants where the owner used dish detergent, even in a mild solution, resulted in sever foliage burn. And if the solution gets into the soil and is not rinsed out immediately, the roots can also suffer to the point of plant death.

Because this is such a time consuming method of eradication, the best method is by preventing the problem in the very beginning. As I stated earlier, insects are out there and they are looking for food. If you can take a few moments one day each week to carefully inspect each plant, you are in the best position to stop an infestation completely. Check each plant by looking on the top and bottom of leaves, checking the branches and stems, and looking at the soil; you will see anything that may develop in to something that may harm your plant. An infestation begins with just one or two individuals, and by killing any bugs with your fingers, there will never be a problem. If, of course, you let several weeks or months go by, then you may find a big problem. Again, it is being in this routine of careful examination that is most beneficial to you and your plants.

I cannot stress the importance of this weekly check because the consequences are so difficult to eradicate and all too often the plant dies long before the insect infestation. I have lost many prized plants to the treatment of an infestation. The chemicals take a toll on your plants, especially if the plants are weakened by an infestation. By giving your plants all the light they need, the proper amount of water they require, and an occasional solution of fertilizer, you can keep your plants healthy and strong and that will help them fight off any insects that may try to munch on them.

I want to mention one major factor that often is a cause for an insect infestation. This is placing your plants outside for the summer months. Because the United States has a tropical-like summer, tropical plants thrive when placed out side where they will get high light, high humidity, and gentle warm breezes--all the elements for a thriving plant. (See the article Placing houseplants outside for the summer.) This is not where the problem lies. It is when you bring the plants back in for the winter months that cause the plant to weaken due to the lower light and humidity levels. When the light level drops, the plant cannot sustain all the beautiful new growth of summer, and drops all the leaves it needs to balance the amount of food production with the amount of foliage. When being out side, the plant is also subjected to all the insects in nature, and combined with the weakened effect of the reduction in light, an infestation can gain hold even faster than if the plant remained inside all summer.

These are proven methods of eradication and prevention of insect infestations on houseplants. With patience and persistence, they work every time in helping to keep all your indoor plants healthy and strong.

Here is a list of indoor plants that mealy bug love:
-African Violets--streptocarpus (Cape Primrose)--All Succulents and Cactus--All Ficus--All Hdera (Ivies)--All Beginias ---Most Dracaena species--Clivia--Aglonema (Chinese Evergreen)--Coelus--Dieffenbachia (Dumb cane)--Anthurium Hibiscus--Poinsettia (Which is a succulent. See "Oh those Pionsettias!")--Philodendren and Pothos (Devil's' Ivy)
-All Genariads: Aescanthanthus Lipstick vine), Columnea (Goldfish Plant), Epescia
-Fittonia--All Citrus--Gardenia--Dizygotheca (Fales Aralia)--Fatsia (Japinese Aralia)--Gynura (Purple Passon)
-All Hedera (Ivy)--Strlitizia (Bird of Paradise)--Heliconia--Heptaplerurum (Arboricala)--Scheflera--Hypostes (Pola-a-dot Plant)--Mantra (Prayer Plants)Plectranthus (swedish Ivy)--Podocarpus (Buddhist Pine)--Saxifraga (Strawberry Begonia)--Senicia (Geraman Ivy)--cisus and Rhoicussus (Grape Ivy)--Tetrastigma (Chesnut Vine or Lizzard Plant)
-All Orchids.

As you can see, the list is extensive. In fact, there are very few of the tropical indoor species that mealy bug will not attack. So be on the loolout for them before they become a major problem.
HAPPY GARDENING

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Diagnosing Plant Problems

When Your Plant is ill, Correcting the Problem is Fairly Simple Once You Know What the Problem Is!

Plants soften the look of any home, and bring lots of fresh, airy feeling to a harsh landscape. Wherever you have planted any type of vegetation, you will have more disease than you would if the plants were in their native home. Fixing the disease is key to the survival and beauty of the plants. Whether the plant is in a home, or outside in a landscape, the same diseases exist, and the remedies are the same. In this article I will go over the most common plant diseases and how to cure them.

Stress factors are one of the first things to consider when trying to remedy your plants. While stress is not a disease, when a plant is stressed it may become diseased much easier than when it is healthy and thriving. One cause of stress to a plant is over watering. When the soil is constantly wet the roots may rot and impair their ability to absorb the water and keep themselves moist. Another cause of stress is a pot that is too small for the size of the plant. If the balance is way off and the plant outside the pot is larger than the roots the pot cannot hold enough soil and water to nourish the plant properly. Constant watering to try to keep the plant hydrated can lead to compacted soil and reduces air spots which will deprive the roots of oxygen. This can lead to reduced root development and plant growth. Frequent watering and quick absorption of the water also may lead to a high accumulation of soluble salts. These salts may leave to the plant not being able to absorb the moisture and may even kill the leaves and eventually the entire plant. The soil may also develop channels through which the soil runs through quickly and prevents all the soil from becoming moist. Repotting with fresh soil will remedy many of these situations.

Now, onto common diseases and disorders that affect houseplants and plants in your landscape. Some problems may not be easily cured at home, but many are. If you have a plant that is very important to you, you may need to take it to a local laboratory and have a technician diagnose the disease or disorder and help you solve the problem.

Leaf spots affect many plants. On shade loving plants, the sun can cause spots on the leaves. These spots are usually large with regular edges. The injured areas may appear bleached, with gradual color change and eventually leading to curling and collapsing of the leaf. Leaf spots that are from a chemical injury, cold water droplets or temperature changes usually appear small and yellow at first. They generally conform to the shape or size of water droplet or chemical that was applied. Leaf spots from fungi and bacteria are often small water soaked spots that gradually enlarge and turn brown. There also may be a considerable amount of yellowing around the spots. Plants may also develop leaf spots that result from a sap-sucking insect, such as an aphid, scale or mealy bug. These spots may be covered with a glistening, sticky fluid. To control leaf spots you will first want to remove and destroy and leaves that are affected. You will want to avoid sprinkling water on the leaves, but apply the water directly to the soil around the base of the plant. Providing adequate air circulation will help protect and prevent your leaves from acquiring new leaf spots. If you suspect insects are causing the leaf spots you will want to wash the leaves with a commercial pyrethrin spray for house plants. If you spot the insects, you can apply rubbing alcohol to kill the bugs with a cotton swab.

Yellowing of leaves is also a specific problem of plants. Typically if your leaves are turning yellow you have a nutrient deficiency. Yellow leaves may also be caused sudden reduction of light. To control this measure, you will want to apply fertilizer. Nitrogen fertilizer is the best to cure yellow leaves as it promotes healthy, green leaf growth. During the winter months you will want to be careful to avoid over fertilizing as the light is low and growth is minimal. Large plants will take some time to absorb the nitrogen into their leaves due to the size of the plant. If the entire plant becomes yellow, you may still have a nutrient deficiency, but it is probably starting with the roots. The plant's roots may be water logged and beginning to rot which results in improper moisture and nutrient absorption. To remedy this problem you will want to add more drainage holes to the pot or change the soil conditions.

Another disorder common among plants is wilting. Leaves become limp and floppy. Many times the leaves will recover with a watering. Over watering or under watering may cause wilting, as well as over-fertilization. If the plant becomes too dry, the leaves will wilt resulting from dehydration. To remedy the problem you will most likely want to alter your watering schedule to water more frequently. You may also want to see if there is some reason why the water is being absorbed or lost quickly. Some times the soil forms channels and the water runs right through the channels and out the bottom of the pot. If this is the case you will want to completely moisten the soil to rid the pot of these channels. You can also inspect the pot to be sure there are no cracks or holes where the water is escaping.

Some plants will experience a loss of foliage. In this case the plant suddenly looses some or all of its leaves. Generally this loss of leaves is caused by a sudden change in an environment. Citrus plant and Jade plant are particularly susceptible to this condition. To help avoid this problem, you will want to make any changes very gradual to the plant. If you are going to be moving, try to prepare the plant with similar conditions it will experience in the new home. You will also want to check that your plant is not located near a draft where the temperature changes suddenly many time throughout the day.

Edema is a plant disease which causes small water soaked pimple- like spots on a plant. These spots usually develop into a small scab type of wound. This condition is usually caused by a rapid change in moisture. To avoid this problem, you will want to keep steady moisture availability to the plant, and be careful when fertilizing to avoid apply too much fertilizer.

Scorch is another common plant disease that causes dead areas on the edges of the leaves. This disease may appear as a burnt tip of the leaf. Scorch is generally caused by high levels of salts in the water and also from physical damage. Bumping or crushing the leaves may result in scorch. If there are high concentrations of salt in the soil, you may notice a brown to yellow clump of crystals along the soil edge. To remove the salts from the soil you will need to leach the plant, running water through it until all the soil is evenly moist. It is also important to remove any water that runs out of the pot from the drip tray after watering.

Plants may be difficult to grow and seem to be a lot of work, but a beautiful houseplant, or stunning landscape is a gardeners dream! By carefully observing your plants, you will notice what is wrong and be able to remedy the situation quickly. Your plants will continue to grow and produce beautiful foliage and flowers!

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