Dealing with Rose Diseases

Growing Healthy Roses

Despite the best efforts to keep roses disease free, there will inevitably be period problems to deal with. Keep tabs on your rose bushes so that you can remedy the situation before it gets out of hand. Be sure to accurately identify the problem before reaching for a spray and start with the least toxic solution. You can read more about organic controls in An Overview of Some Common Organic Garden Pesticides.

The Big 4 of Rose Diseases

Black Spot: Black spot is a fungus that is very common during humid weather because it is a water-bourne disease. As its name implies, small black spots form on leaves and stems, eventually causing the leaves to drop and weakening the plant.

Treatment: Choose black spot resistant varieties and be meticulous about sanitation.

1. Water the roots of the rose, avoiding the foliage. Water in the morning, so that splashed leaves have time to dry off. If Black Spot is an annual problem, try a dormant spray of lime sulfur at the end of the season and again in early summer. Once Black Spot appears, it is hard to stop. Neem oil and Sprays containing Potassium bicarbonate are somewhat effective.

   
   

2. Downy Mildew: Downy mildew is a very serious disease that spreads rapidly and can defoliate a rose plant in days. It is not as common as Black Spot and favors cool, wet weather. Purple spots with yellow edges form , often on the veins on the top side of the leaves and along the stems. Pale gray fuzz can form on the under side of the leaves. The leaves will eventually become brittle and fall.

   Treatment: The good news is that Downy Mildew often clears up with the weather. To reduce the chance of Downy Mildew, practice good garden sanitation and keep the rose plants well pruned for air circulation. As with other diseases, a dormant spray may help.

   
   

3. Rust: A Rust infection is easy to spot. Small orange pustules spots form on the undersides of the leaves. This fungus can also cause defoliation. Rust is most prevalent when nights are cool.

   Treatment: Treatment of Rust is similar to treatment of Black Spot, above: Good sanitation and a preventative dormant spray after pruning. Once infected, remove all infected leaves and try Neem oil for control.

   
   

4. Mosaic Virus: Once a rose is infected with Rose Mosaic Virus, there’s not much to be done except check with the nursery for a replacement. Rose Mosaic Virus shows up as yellow mottling on leaves and deformed new growth. It can stunt growth or it can be a mild infection. If there are only a few affected leaves, the plant may continue growing and blooming fine. The really good news is that it won’t spread to your other rose

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Rose Growing Problems

Prevent Problems Before They Occur

Any gardener who has grown roses knows that sooner or later you are going to encounter a problem or two. But growing roses isn’t as difficult as you might have heard. Choosing the right type of rose and giving it the care that it needs are common sense approaches to carefree plants. Planting your roses in combination with other plants, rather than in an exclusively rose garden, can further cut down on problems. However we are often drawn to the beautiful prima donas in the rose world and these will require more attention. The best remedy for rose problems is a good defense.

Prevent Rose Problems Before They Occur

Choose Resistant Varieties: Where you are gardening plays an important role in which roses you should be growing. Humid areas will always be prone to mildew.

1. Hot, dry climates need roses that can withstand a little drought. Check with your local Cooperative Extension Service for a list of disease resistant varieties for your area.

2. Keep Them Healthy & Vigorous: Pests are bullies and they will pick on the weakest plants first. Unless you’re growing roses to compete, rose bushes aren’t nearly as fussy as you may have been led to believe.
   • Keep your roses watered and feed.
   • Don’t over do the nitrogen. Lots of tender new growth attracts aphids.
   • Prune to allow air circulation, particularly in humid climates.
   • Stop pruning at least 6 weeks before expected frost, so new growth is not damaged by the cold.
   • Mulch around rose plant roots to prevent soil born diseases from splashing onto leaves

3. Clean up Fallen Debris and Dead and Diseased Plant Parts: Good sanitation can foil a lot of problems.
   • A mildewed leaf that falls and remains on the ground will send spores to the rest of the plant.
   • Insects and diseases can both over winter in leaf debris
   • A damaged or dead branch is an inviting entry point for many pests

4. Learn Which Insects are Problems and Encourage the Good Guys: Random spraying of insecticides does more harm than good. There will always be more trips flying in or more aphids being born. Encourage the insects that feed on these pests. And don’t panic at the first sign of a pest. If there are no pests, there will be no reason for the beneficial insects to take up residence in your garden. There needs to be a balance in your garden.
   • Lady beetles are renowned aphid eaters.
   • Green Lacewings eat aphids, mites, thrips and many insect eggs.
   • Predatory Mites feed on thrips and spider mites
   • Parasitic Wasps attack caterpillars

   Unfortunately there doesn’t appear to be an insect predator for Japanese Beetles. Pesticides aren’t particularly effective against adult beetles and hand picking is your best option.

5. Avoid Annual Diseases with a Preventative Spray: Even during years of drought, humid climates can expect some Black Spot on roses. A dormant spray of a fungicide applied after pruning will help greatly in offsetting the problem. A rose fungicide containing either lime of copper is a good low toxic choice.

Organic Rose Gardening

Can Temperamental Roses Be Grown Organically?

Roses have acquired the reputation of being fussy plants. We’ve all heard that to grow beautiful roses requires chemicals and systemics. Is it possible to grow roses organically? Of course. After all, roses can survive for many years without any attention at all. Just think of the antique roses being rediscovered in abandoned cemeteries or the invasiveness of the multiflora rose in the northeast.

Growing roses organically is really no different than growing any type of plant with organic techniques. Keep in mind that organic gardening involves more than just not using chemicals. It means giving the plant what it wants and needs to grow well. Do that and you’ll have a healthy plant, better able to withstand pest attacks.

Unfortunately that is often easier said than done, especially with something as sentimental and sensual as roses.Gardeners are very particular about what type of rose they wish to grow. It can be very hard to give up the idea of long stem tea roses in favor of shrubby rugosas, but choosing the right rose for your area is rule number one.

If you’re willing to make some adjustments in your dream rose garden, here are some guidelines to growing roses organically.

• Choose roses suited to your area’s zone and climate. Tea roses grow very easily in hot areas, but where winters can be frigid, the Explorer series and old-fashioned rugosas will be much hardier.

• Select roses resistant to the diseases that are common in your area.

• One you’ve chosen a rose, research it so you’ll know exactly what it likes.

• Create wonderful soil by adding lots of organic matter.

• Keep the soil pH slightly acidic (6.0 - 6.5).

• Plant your roses in full sun - Provide afternoon shade in hotter climates.

• Allow space between plant for air flow and circulation.

• Use plant diversity to keep insect populations down. Under plant with a different type of plant.

• Water the roots, not the foliage.

• Water deeply and give them special attention during dry spells.

• Pay attention to lower leaves, where splashing fungus spores will often take hold first
• Mulch with organic matter. Keep their feet cool.

• Feed them regularly
  1. in the spring, after pruning
  2. while they are in bud
  3. in mid-summer (at least 6 weeks before the first expected frost)

Prune at the right time of year.

Promptly remove diseased or damaged wood.

Clean-up fallen leaves and debris.

Consider companion planting to deter bugs. Alliums to repel nematodes, nasturtiums to trap aphids, alyssum, geranium, rosemary and thyme to attract beneficial insects.

Take care of small problems before they become big problems

Learn to expect and tolerate a little imperfection.

It’s hard to avoid black spot on your roses. If yours become infected, reach for organic solutions. Don’t reach for systemic pesticides that are going to throw everything out of balance.

If you have black spot every year, consider improving both the air circulation in the rose garden and the vigor of your roses. Messenger, a plant health activator, fools the plant into thinking it's being attacked by disease and triggers its immune defenses. The plant is actually fine, but it is better able to ward off disease.

• Bordeaux mix helps to prevent fungal diseases, including black spot and powdery mildew. If it’s a problem every year, do a preventative spray right after spring pruning, but before the leaves open.

• Potassium bicarbonate fungicides can be used on mildew during growing season, in extremely humid areas. It tends to be safer than the homemade solutions with baking soda (sodium bicarbonate).

• Severe fungus infections can be treated with copper or sulfur fungicides.

This may seem like as much work as growing with conventional treatments, but most of these techniques involve starting your roses off with the right conditions. Think in terms of making your roses happy and prevention before control and you’ll be thinking like an organic rose gardener.

Hybrid Tea Roses

Pruning and Using Hybrid Tea Roses in the Garden

Using in the Garden

Hybrid tea roses are the plants used in traditional rose gardens. They are often planted in rows, by themselves, because it’s easier to care for them that way. Space them anywhere from 18 - 36 inches apart, depending on the growth habit, and keep weed free.

Hybrid teas are grown for their blossoms, not their landscape appeal. They can work unexpectedly well in a border, especially with a low growing perennial covering their gangly stems. Artemisia, true geraniums, lavender and nepeta works well as partners with hybrid teas.

Pruning

Pruning hybrid teas is not unlike pruning other rose types. If you are regularly cutting the blossoms, you will actually have less pruning to do. When selecting hybrid teas, keep an eye out for some of the thornless varieties. Most have the word ‘smooth’ somewhere in their name. Thornless takes some of the pain out of pruning.

• Prune in early spring, before new growth.

• When cutting roses, be sure to leave a few leaves on the stem.

• Make cuts about 1/4 inch above an outward facing bud.

• Make cuts at a 45 degree angle, so that water runs off.

• First cut out anything dead, diseased or damaged canes.

• Cut out scrawny, spindly canes of less than ½ inch in diameter.

• Prune remaining stronger canes by about a third of their length, down to 12-24 inches. Hard pruning like this encourages strong stems and large flowers.

• Prune to open and shape the plant and allow the plant to put its energy into fewer flowers.

Judging Great Rose Blooms

Even an imperfect rose blossom is a pleasure, but if you get the bug to compete with more than your neighbors, here are the criteria hybrid teas are judged by. Each quality is graded on a specified number of points with the highest combined total of all points being 100.

Most important features:

• Shape or form
• Color

Then comes Substance:

• Freshness and sheen

Other considerations rated:

• Balance and proportions
• Size
• Stems and Foliage

For the specifics, read more about Exhibiting Roses at the American Rose Society site.

Hybrid Tea Roses - Selecting, Growing and Caring for Hybrid Tea Roses

Hybrid tea rose, a cross between hybrid perpetuals and old fashioned tea roses, are rose royalty. They are the most popular rose in the world and perhaps the most popular flower. Hybrid teas have all the virtues you look for in a flower: beauty, fragrance and easy care.

What Makes Hybrid Tea Roses Different from Other Roses?

Hybrid teas generally produce only one blossom at the end of the stem, rather than clusters of flowers. They have an open rather than bushy habit. Virtually all are repeat bloomers throughout the growing season and offer some degree of fragrance.

The flowers on hybrid tea roses may have over 60 petals and be as large as 5 inches across. A signature of hybrid teas is the long, pointed buds that open by slowly unfurling. Plants will grow anywhere from 3-6 feet tall, depending on the variety and the growing conditions.he long, strong stems make them great cut flowers. Hybrid teas have been cultivated in almost every color except blue, with many extraordinary bi-colors to chose from.

Choosing the Right Hybrid Tea for You

As with any other type of plant, not all hybrid teas are created equal. However, the idea that hybrid teas are fussier than other rose types is unwarranted. The key, as always, is to choose a variety suited to your climate and zone.

• If your summers are humid, look for mildew resistance.

• Where summers are dry, look for heat tolerance and vigorous root systems.

• Be extra certain of zone ratings if you live where winters are harsh and provide extra protection. Roses with thick petals are hardier in variable weather and last longer as cut flowers.

Planting Hybrid Tea Roses

If your rose plants come bare root, remove the packing around the roots and soak them in a bucket of water for at least 2 hours and up to 24 hours.

• Be sure the soil in the planting area is loose and rich in organic matter.

• Dig a hole large enough to spread out the roots, usually 12-18 inches in diameter.

• Make a cone-shaped mound with soil, in the center of the hole and spread the roots out over the mound.

• Check the depth of the rose in the hole by placing a shovel handle across the hole.

• As with many cultivated flowers, hybrid teas are bud grafted onto hardy, disease resistant root stock. The bud union, the visible knob at the base of the plant. In warm climates the bud union should be 1-2 inches above soil level. In colder climates, bury the bud union 1-2 inches below ground level. This union should always be protected in cold winters.

• Fill the hole half way with soil and water well to remove any air pockets.

• Finish filling with soil and water again.

• Once the rose is planted you can prune the top growth.

Watering Your Roses

As with most garden plants, an inch or two of water a week is usually sufficient. Of course this depends on your climate and growing conditions. Hot locations and sandy soil will need more frequent watering than cool, coastal regions. A better gage: If the top 3 inches of soil are dry, it’s time to water.

• Water the soil, not the leaves, to prevent disease.

• Water deeply to encourage roots growth. Strong, deep roots will help your roses survive periods of drought.

Feeding Hybrid Teas

Hybrid tea roses, being repeat bloomers, are heavy feeders and benefit from regular applications of food.

• Start in early spring either a month before new growth or when you remove winter protection

• Continue feeding weekly or every other week, depending on the fertilizer being used.

• Choose a balanced fertilizer or one labeled for roses.

• Hybrid tea roses like a slightly acid soil (6.0 - 6,5 pH).

• Iron is especially important if the soil’s pH is too high. If the leaves turn yellow with green veins, use an iron supplement.

• Magnesium sulphate (Epson salt) is thought to intensify flower color and encourage flowering canes. If your soil is already high in magnesium, adding more won’t help. If not, scratch in 1/4 to ½ cup per plant once or twice a year and water well.

• Stop fertilizing about 6 weeks before your first expected frost date. You don’t want tender new growth on your plants that will be damaged by a change in weather.

Mulching Rose Bushes

Mulch to cool the roots and conserve water.

• Add a 3-4 inch layer of mulch in the spring, when removing winter protection.

• In warmer climates, mulch when the leaf buds begin to swell.

Flowering Trees and Shrubs

When is the Best Time to Prune?

When you can’t wait to get started in the spring garden, a good task to undertake is pruning. Most trees and shrubs benefit from annual pruning. It keep them in shape, gets rid of dead and diseased wood and encourages new growth. But not all trees and shrubs should be pruned early, especially some of the flowering ones.

Early spring bloomers set their flower buds the fall before. Pruning them early in the spring would mean losing some blossoms. Most of the time this is not what you want. However there are exceptions. It’s often easier to prune when you can see the shape of the plant, before the branches are masked by leaves. Trees and shrubs that are in need of a good shaping could sacrifice a few blooms to be invigorated by a spring pruning.

There are no hard and fast rules, but here is a of list of commonly grown spring flowering trees and shrubs and the best time to prune them.

Trees and Shrubs to Prune in Late Spring/Summer, After Bloom

• Azalea (Rhododendron species)
• Beautybush (Kolkwitzia amabilis)
• Bridal Wreath Spirea (Spirea x vanhouttei)
• Flowering Crabapple (Malus species and cultivars)
• Forsythia (forsythia x intermedia)
• Hawthorn (Crataegus species and cultivars)
• Hydrangea, Bigleaf (Hydrangea macrophylla)
• Lilac (Syringa vulgaris)
• Magnolia (Magnolia species and cultivars)
• Mockorange (Philadelphus coronarius)
• Mountain Laurel (Kalmia latifolia)
• Rhododendron (Rhododendron species)
• Serviceberry (Amelanchier x grandiflora)
• Slender Deutzia (deutzia gracilis)
• Weigela (Weigela florida)

Trees and Shrubs to Prune in Early Spring, While Dormant

You can still get your pruner out this spring to shape the following list of trees and shrubs, while they are still dormant.

• Bradford Pear (Pyrus calleryana)
• Butterfly Bush (Buddleia Davidii)
• Crape Myrtle (Lagerstroemia indica)
• Flowering Dogwood (Cornus florida)
• Flowering Plum (Prunus blireana)
• Glossy Abelia (Abelia x grandiflora)
• Golden Rain Tree (Koelreuteria paniculata)
• Honeysuckle (Lonicera fragrantissiam)
• Hydrangea, Peegee (Hydrangea paniculata ‘Grandiflora’)
• Potentilla (Potentilla fruticosa)
• Redbud (Cercis canadensis)
• Spirea (except Bridal Wreath) (Spirea japonica))
• Wisteria (Wistera species)

How To Prepare Your Roses for Winter

All roses need some attention going into winter. Winter weather in zones 6 and below can really challenge rose bushes, particularly the hybrid teas. Shrub roses are hardier and can pretty much fend for themselves, but the hybrid teas and other modern hybrids are a little fussier. Here are some tips for winter rose survival, starting with zones 6 and below:

Difficulty: Average

Time Required: 20 - 40 Minutes Per Rose

Here's How:

1. Stop feeding and pruning your roses around the end of August, to discourage tender, new growth that will suffer from winter damage.
2. After the first frost, thoroughly water the soil around your rose bush. Once the ground freezes the bush has to take care of itself, so give it a good soaking going into winter.

3. Remove all fallen leaves to prevent diseases and insects from overwintering.
4. After a couple of hard freezes, mound 6-12 inches of compost around the crown of the plant, to protect the roots and the graft union where the rose species you are growing is attached to a hardy root stock. The graft should be at or just below the soil surface. In a mild winter, you could also circle the rose with wire and stuff this cage with leaves or mulch.
5. Climbing roses are at risk from strong, drying winds. To protect the canes of canes of climbers, either wrap the canes together bundling something like straw on the outside for insulation or remove the canes from their trellis or support and lay them on the ground. Then tie the canes together and secure them to the ground with landscape pins. Protect with a layer of mulch.
6. Zones 7 & 8 always stand the chance of a freeze and maybe even some snow. The graft union would benefit from protection, but it need not be as heavy as for zones 6 and below. Mounding with leaves or a shredded mulch should suffice.
7. The rule about discontinuing pruning at the end of summer holds for zones 7 & 8 too.
8. In zone 9 and above, where roses won't be subject to freezing temperatures, watch for fungal diseases that can creep in with the cooler, wet weather.
9. Roses are still growing and setting buds in zone 9 on up and November is a good time for a light feeding. Prune after the plants bloom in December.

Tips:

1. Don't try to use the soil around the rose bush as mulch. Moving it could expose or disturb the roots.
2. Don't forget to remove protective mulch in the spring.

History and Meaning of White Roses

Primary Significance: Purity, Innocence, Sympathy, Spirituality

With its pristine appearance, the white rose has come to symbolize purity, innocence and secrecy. There are myths and legends from several different cultures relating to the origin of the first rose which is initially white in color and is then miraculously transformed. Oftentimes the pure white rose was depicted as being stained by blood, or made to blush from a kiss. The recurrence of this theme does a great deal to establish the white rose as a symbol for purity.

Early traditions also used white roses as a symbol for true love, an association which would later become the hallmark of the red rose. However, white roses continue to endure and retain their symbolism of innocence. White roses are now used to express a number of different sentiments.

Also known as the bridal rose, the white rose is a traditional wedding flower. In this sense, they are a representation of unity, virtue, and the pureness of a new bond of love. White roses are also a symbol for young love, which further strengthens the association, and makes them ideal for marriages. Bridal bouquets are often comprised of white roses and other white flowers.

White roses are also associated with honor and reverence, which makes them a fitting memorial for a departed loved one. Funeral and sympathy arrangements traditionally incorporate white roses as a part of the tribute. As a symbol of remembrance, the white rose represents heavenliness and is an expression of spiritual love and respect.

While most of the long-established meanings of white roses are still quite commonly used today, others have become less prevalent. White rosebuds, for example, are a traditional symbol for girlhood and carry an underlying message of one too young for love. While perhaps no longer falling into the realm of common knowledge, this is still very much a part of the language of roses.

White roses can mean many things to many different people. They can symbolize new beginnings, or be a sign of farewell. They can convey feelings of love, friendship, respect and hope. Underlying all of these messages is the impression of innocence and purity with which white roses are now synonymous. An arrangement of white roses is not only beautiful; it can carry a complexity that belies its simpler appearance. Whatever the reason white roses are given, it can be assured that they will be deeply appreciated by their recipient.

Meanings of Roses Based on Colors -- Red Valentine Roses for Lovers

When giving cut roses as Valentine gifts, we adhere to a time-honored formula that takes into account rose color meanings. The formula matches a rose's color to its intended meaning as a gift. Valentine's Day is primarily a lovers' holiday, and red roses are traditionally for lovers. "Valentine roses" and "red roses" go hand in hand, even though other colors have their place on the holiday. Our close family members may also be treated to red roses for Valentine's Day, but we avoid giving roses of this color to friends on Valentine's Day -- that would simply convey the wrong meaning. The following are the meanings traditionally attached to the most popular roses, according to colors; use this list as a guide when selecting Valentine roses:

• Red roses mean romantic love; they're the "Valentine roses," par excellence.
  
  
• Purple, coral and orange challenge red as the color for Valentine roses. The rose color meanings for these 3 are as follows:
  • The specific purpose of purple roses is to signify that the giver has fallen in love with the recipient at first sight.
  • Meanwhile, coral and orange roses signal desire.
  
  
  
• The meaning of yellow roses is joy and friendship.
  
  
• We express our gratitude and appreciation with pink roses....
  
  
• While feelings of admiration and sympathy find words with roses that are light pink in color.
  
  
• Peach is more ambiguous, as it can signify either sympathy or gratitude.
  
  
• Their purity naturally enough lends to white roses the meaning of reverence and humility.

What about black roses? Do they exist and, if so, what is the meaning? While no jet-black rose exists, there are some of such a deep red as to suggest black. E.g., Rosa 'Black Magic.' Alternatively, some florists dry fresh roses and dye them black. And the meaning? There is some disagreement on this point. Many say black represents death and can thus be used as a symbol to express vengeance towards a foe. But others interpret that more liberally, suggesting as a meaning for black roses the death of old habits, thus signalling rebirth.

Unless you're a "Goth" or are trying to be funny, I'd stay away from sending black roses: the interpretation is too iffy. But the formula listed above will work for the other colors. Just follow the formula that matches the colors with the corresponding meanings, and you can't go wrong as a gift-giver. But is growing rose bushes in the yard also that simple? Yes, it is. Nor is there any great mystery surrounding it (although pruning roses can be tricky for the beginner, the subject of Page 2). The formula for growing rose bushes is a well-known one, since it is a formula that the average landscape plant lives (or dies) by:

sun + water + drainage + rich soil = rose success

I use the terminology "rose bushes" to refer generally to all roses, regardless of form, which can range from miniature shrubs to sprawling climbers. Once you're committed to following the formula for growing rose bushes, for maximum success you'll simply have to tweak the formula a bit and add some extras. For instance:

• While roses like six hours of sun per day, it does matter what part of the day those six hours come from. Six hours of morning sun is preferable to six hours of afternoon sun, for two reasons:
  1. Rose bush foliage prefers to be dry. The quicker the dampness from the night is burned off the foliage, the less likely disease is to become a factor.
  2. The afternoon sun is often excessively hot. Roses profit from some afternoon shade.
  
  
  
• To keep insect pests off your rose bushes, try companion planting with garlic. And once per week, while watering your rose bushes, mix some dishwashing soap into the water and apply this "insecticidal soap" to your bushes (of course, there are also true insecticidal soaps that you can buy).
  
  
• As always, soil pH is a consideration. Roses prefer a pH ranging from 6.5 to 6.8.
  
  
• For fertilizing roses, a monthly feeding of rose food is recommended.

Care for Rose Bushes on the Landscape: Overwintering, Watering:

• In cold climates roses can be mulched, but if you really want to make sure your bushes are protected, practice a winterizing method called the "Minnesota Tip."
  
  
• Roses need a lot of water (how much "a lot" is will depend, of course, on many factors). As in the case of sunlight hours (see above), not all rose-watering methods are created equal. On the average, it is best to water rose bushes twice a week -- and to water them thoroughly. It would be better to water twice per week deeply than to apply four shallower, less thorough waterings over the same time period.

These are some of the basics of rose bush care. Not too difficult, right? In fact, since there's a logical reason behind all these tips, they're probably easier to remember than the rose color meanings, which would seem to be rather arbitrary. On Page 2 we'll look at pruning techniques, as well as selecting a rose bush and getting it into the ground properly in the first place....