Hybrid tea roses (Rosa ‘Osiria’) are known for their two-toned, dramatic petals.
It’s anything but generic.
Plant Attributes
Osiria Rose Care
The Osiria rose grows in various climates.
Credit: Getty Images
When adding one to your garden, start with good soil that drains well.
With this rose, things can develop slowly, so don’t get discouraged.
When planting, plenty of direct sunlight is ideal.
More sun spells more flowers.
However, you also want the location to protect from wind and rainthe heads will droop on weak stems.
Some cultivars can be invasive in areas where they can spread.
Light
Osiria roses grow best in full sunlight, at least four hours daily.
Sunlight also helps produce bigger, showy blooms.
Soil
All roses prefer soil rich in organic matter.
The hybrid tea rose prefers nutrient-rich, acidic soil that’s well-draining and loamy.
Add mulch to the ground in the spring after the last frost.
Mulching to the roots helps conserve water and protect the plants in warmer weather when the leaf buds begin.
Water
The Osiria rose water requirements vary depending on temperature and soil conditions.
On average, one to two inches of water every week is enough for the hybrid tea rose.
When it is time to water, you will know because the top few inches of soil are dry.
Avoid watering the foliage and instead focus on the roots.
Deep watering builds strong roots and helps during warmer temperatures.
Temperature and Humidity
Hybrid tea roses are relatively cold-tolerant when sold as bare-root plants.
These plants will go dormant in late winter or early spring.
Most rose varieties bloom best in warm, humid conditions, at least 80F.
Fertilizer
Osiria roses benefit from regular fertilization.
After the last frost and before new growth, start fertilizing plants every week or every other week.
Fertilizers designed for roses typically include nitrogen, phosphorus, and potassium.
Adding nutrients like iron and magnesium sulfate can help produce healthier plants depending on the soil.
Iron reduces yellowing leaves, and magnesium sulfate helps produce showy blooms.
Stop fertilizing about six weeks before the expected first frost to stop new growth and encourage dormancy.
Types of Osiria Roses
Osiria roses have several cultivar varieties.
Each cultivar highlights unique colors, fragrances, and petals.
Make these cuts at an angle, around 45 degrees, to help water drain from the ends.
Prune before new growth emerges in the spring.
Remove the dead, diseased, or damaged canes to encourage new growth.
If the branches are more substantial and healthy, prune only a third of the stem’s length.
Propagating Osiria Roses
There are several ways to propagate roses.
Cuttings, air layering, or budding can propagate the Osiria rose.
Several cultivar varieties are patented, so always check the propagation guidelines before growing from seed or propagation.
Budding is an easy way to create more Osiria roses using the parent plant’s buds.
Overwintering
The Osiria rose is relatively cold-hardy depending on the environment when meeting certain conditions.
The soil must remain moist, and pruning will help protect the plant’s roots during the colder weather.
Remove this additional soil after the last frost and before new growth emerges in the spring.
Pruning the canes is another way to protect the plant by reducing the energy needed to preserve longer branches.
Maintain proper water drainage and sunlight requirements to help prevent infections from forming.
Rabbits and deer are known to eat these flowers.
If plagued by a pest infestation, use insecticidal soap as directed until resolved.
How to Get Osiria Roses to Bloom
Maintain adequate sunlight and soil health to encourage blooms.
Fertilization should occur in early spring, after pruning, and after the season’s first bloom.
Protecting the plant’s root bulb during winter will help ensure healthy blooms.
Leaves Turning Yellow
Yellowing leaves typically indicate overwatering.
When the soil does not drain properly, Osiria roses can begin to droop.
Not enough sunlight and improper soil pH can also cause yellowing leaves.
Black spot disease is present when overwatering continues and will be visible on the upper side of the leaves.
After, apply a fungicidal spray for a few weeks to prevent the new spots from appearing.
Curling Leaves
Sawfly infestations can cause leaf curling in roses.
Fungal infections, such as powdery mildew, can also cause curling leaves.
Before white spots appear on the leaves, rose foliage may curl, indicating that powdery mildew is present.
Horticultural oils can also help to prevent the disease from spreading.
