Potomac Rose Society

Potomac Rose Society

Species Roses Classes of Roses Old Garden Roses Modern Roses

Modern Roses After 1867 Floribundas Polyanthas Grandifloras Hybrid Teas Modern Shrubs Miniatures & Minifloras Large-Flowered and other Modern Climbers

Floribunda - Iceberg Rose

In 1954 Queen Elizabeth was designated the first Grandiflora. The shrub is large, the flowers similar to those of the hybrid tea, but with sprays like a Floribunda. Grandiflora

Hybrid Tea roses grow on single, long stems. Flowers are large, buds are pointed. Hybrid Teas bloom in flushes in the spring and fall. They come in all colors. Hybrid Tea

Golden Showers

Miniatures and Minifloras Miniatures are small roses growing on small bushes that sometimes exhibit Hybrid Tea form. Minifloras are similar to Miniatures, but often somewhat larger.

Shrub Roses A catch-all for roses that do not fit into other categories. They range from 4 to 15 and grow in all directions. They have large clusters of flowers. Some are hardy and very disease resistant. David Austins and Knockouts are shrub roses.

Fundamentals of Site Preparation You have found a site with good sunlight, good drainage, airflow, and one not compromised by large trees, subject to the limitations of our area Next Step: What are the keys to preparing your site? 1. Digging a proper hole 2. Amending the soil Both are absolutely critical and must be done correctly at initial planting post initial planting it is very difficult to fix either

What makes a Proper hole? Common Problem: Too often people fail to dig a big enough hole Result: Roots struggle to spread beyond the limits of the initial hole which compromises growth as the plant struggles to take up nutrients Solution: Dig a circular hole with the following dimensions: Depth: 24 inches deep Diameter: 24-30 wide Note: When digging, place the dirt aside, we will use it in the next step: Soil Amendment This is A LOT of digging and depending on soil type, and your back, you might want to consider an alternative: RAISED BEDS

Soil Amendment 101 Common Problem: Roses can still fail even with an ideal site and a proper hole if soil is not amended properly Background: In the DC Metro Area our native dirt is highly acidic and contains lots of clay Good for azaleas and blueberries but not roses Should you discard ALL of your clay soil? No! It has some nutritional value and can be optimized: Solution: In a wheelbarrow or on the ground, mix the following: one half (½) of the dirt you removed when digging the hole an equal amount of compost (leaf grow or garden grow) add some Perlite 2-3 shovels-full per wheelbarrow

General Items Applicable to All Check level of bud union University of New Mexico

Potted Roses Minimize disruption to roots Check level of plant in hole Spokane Rose Society

Bareroot Roses Dormant Typically arrive in early to mid March Plant as soon as you can after arrival Don t let roots dry out Soak in water for 24 hours Dip in 5-10% bleach solution

Bareroot Roses Excavate hole Prune canes and roots Mix in soil amendments Prepare mound of soil Check level of bud union Backfill and water Mound around plant for protection Sunset.com urbanext.illinois.edu

Pruning Principles High pruning for more flowers earlier or low pruning for fewer, bigger flowers later Prune to remove weak and crisscrossing canes Remove growth an inch or more below a canker Remove of damaged, dead, or broken canes back to healthy growth Remove sucker growth as close as possible to main root.

Pruning will encourage future basal breaks. Basal breaks refer to new shoots, soon to be producing canes, which arise from the bud union. These should not be confused with "suckers" which arise from the rootstock below the bud union. Remove all suckers.

Roses Must Have Water Background: Roses are over 90% water Roses with 30 inch drip line diameter need 2 inches of water per week which is 6 gallons, applied 3 gallons at a time twice per week Is rain enough? NO! While you could use a simple rain gauge to measure rainfall, rain is seldom sufficient especially in July & August How can you supplement rain? Soaker hoses Sprinklers Drip systems Using a hose 21

Roses Must Have Water (cont.) During hot summer weather, increase watering frequency: 100 degrees 3 gallons applied 4 times/week 90 degrees 3 gallons applied 3 times/week If you have good drainage, more water will not hurt If soil is compacted, use a garden fork to open holes to a depth of 6-8 inches and gently rock to open airways 22

Fertilizer Overview Without fertilizer roses will not thrive. Roses are very heavy feeders. Nitrogen is the most important part of a fertilizer program. Nitrogen Needs: Roses 24-48 lbs N per 1,000 sq ft / year Grass 3-4 lbs N per 1000 sq ft / year Trees l lb N per 1000, sq ft / year 23

Nitrogen: Common questions about the most important nutrient How much should you apply? (very few of us have 1000 sqft of roses or measure in lbs)? What type should you apply? When should you apply? What else should you apply with Nitrogen? There is no single answer. Rosarians are split between two approaches: Practical or Anecdotal Approach Try a recommended program and adjust as you gain experience and learn from others. Scientific Approach Calculate Needs Remember everyone s microclimate, sunlight and soil are different to some extent 24

Practical Fertilizer Programs Remember: Roses must be hydrated before fertilization and must be watered after fertilization Date Program 1 Program 2 15-Apr 15-Jun 15-Aug 1½ cups Osmocote (18-5-12 8 months) ~or~ 2 cups Osmocote (15-9-12 6 months) 1 cup Mills Magic (6-5-1) ~or~ 1 cup Espoma Plant-Tone (5-3-3) 1 cup Mills Magic ~or~ 1 cup Espoma Plant-Tone 2½ cups Espoma Plant-Tone ~and~ ¼ cup Milorganite (5-2-0-4 Fe) 2½ cups Espoma Plant-Tone 2½ cups Espoma Plant-Tone ~and~ ¼ cup Milorganite Note: Roses in Pots are different. Beginning on April 15, use 2 tablespoons Peters (20-20-20) dissolved in one gallon water and repeat every month through October 25

Major Rose Diseases Blackspot Powdery Mildew Canker Crown Gall Downy Mildew Botrytis Rose Mosaic Rose Rosette Disease

Blackspot Fungus produces round, black spots on leaves. Some leaves will yellow and fall off; complete defoliation can occur. Can also grow on canes/stems. Infection spreads in wet periods. Usually starts on lower leaves. Overwinters in leaf debris and on stems. Disease of most concern.

Blackspot Control Avoid shady locations (roses need sun anyway). Plant (and prune) to allow good air circulation. Clean up fallen debris and overwintering leaves in the spring. Don t wet leaves in evening (but rain will happen). Look for blackspot-resistant rose varieties. Remove lower leaves a few inches up the plant. Begin spray program when bushes leaf out in early spring (spray details at end of talk).

Botrytis Watch for brown or spotted blooms, canes, or shoots. Can develop into masses of gray spores which disperse in a cloud of dust. Infections are favored by cool and rainy weather around 60 F. Can be particularly damaging when rainy, drizzly weather continues over several days. Control: remove spent blooms; sanitation; preventive fungicides (Chipco, Compass, Phyton 27).

Major Insect Pests of Roses Aphids Rose Slugs & Leaf CuFer Bees Thrips Midge Cane Borers Japanese Beetle Spider mites (an arachnid, not an insect)

PesJcide Sprays 101 Many insecjcides, fungicides, mijcides labeled for use on roses. Available products are ever changing. Same acjve ingredient may be sold under different names. Big-box stores vs. garden centers vs. mail-order chemical sprays vs. natural or organics CAUTION WARNING DANGER ALWAYS read and follow label direcjons.

Simple Spray Programs To Prevent Blackspot & Mildew: Banner-Maxx (aka Honor Guard aka Infuse) every two weeks & combine with Mancozeb every other spraying Insects (only when damage present): Water spray, soaps (aphids) Orthene or Merit (aphids, thrips, rose slugs) Spider Mites: Water spray Avid/Lucid

Even Simpler Programs Ready-to-Use Products available at Home Depot, Lowe s, garden centers, etc. Bayer Advanced: 2 in 1 and 3 in 1 products. Combine insecjcide + fungicide +/- mijcide and ferjlizer. READ THE LABELS. RTU liquids in spray bofles; hose-end bofles; granular for soil applicajon. Also FerJ-Lome, Green Light, Garden Safe, Spectracide products. Above lines include organics like neem, hort. oils and soaps.

Whew...that s all folks!