If you’ve never heard of mock orange, you’ll want to grow it after reading about it in this article. These beautiful and fragrant shrubs grow across the dry, rocky landscapes of the western United States and Canada.
Over the past year, I have been building a new home with my partner, and we suddenly found ourselves with lots of land in need of landscaping. When I came across this species, I knew I needed to add it to our lineup.
Whether you’re looking for a simple shrub for the backdrop to your colorful garden or need something to add interest to a hedgerow, this species is ideal. It’s forgiving, beautiful, and easily adaptable.
Overview
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What Is It?
Mock orange is a long-living, low-maintenance perennial shrub with sweet citrusy-floral scented flowers blooming in the early summer months. The scent is described as light jasmine with strong overtones of citrus.
Brief History
Native Americans employed the woody stems for crafting tools, weapons, and furniture.
Mock orange, sometimes called sweet mock orange, has been cultivated since the 1600s and is thought to have originated in Northern Italy, Austria, and Central Romania. It was previously classified under the Syringa genus.
Native Americans used the woody stems to shape tools, weapons, and furniture. The flowers have always been used as fragrance, decoration, and in teas. It also serves as Idaho’s state flower.
Characteristics
This shrub is cultivated for its sweet, fragrant spring blooms.
The height and amazingly sweet, fragrant, and lovely spring blooms of mock orange lend well to borders, hedgerows, or screens. Dwarf varieties do great in containers on patios.
The scent in the air, reminiscent of orange blossoms, will have you aching for spring’s arrival. Plus, it will add elegance and visual appeal to any yard or flower garden.
Some people avoid this shrub because it’s fairly bland for the months it is not blooming. However, its evergreen leaves can easily be incorporated into an otherwise colorful garden and serve as a nice backdrop. It’s a great butterfly attractant, to boot.
Appearance
The growth habit is semi-rounded and can be easily shaped through trimming.
Clusters of 5-7, four-petaled, purely white, cup-shaped flowers are the star of this shrub which bloom in May and June. Leaves are oval, serrated, and dark green and grow densely. The flowers spill over the branches and can grow quite near the ground in a cascading fashion.
Some cultivars have double blooms. The flowers can be used as cut flowers and are a popular option among summer brides for their bright white color and dreamy fragrance. The shrub itself has a semi-rounded growing habit. It can be trimmed into different shapes fairly easily.
Native Area
This versatile plant can thrive from sea level to elevations of 9000 feet.
Mock orange is native to the Western and Northwestern United States, Europe, and Canada. There are 50-65 known species, with 27 of them being native to North America.
It can grow at sea level up to elevations of 9000 feet. It can be found in mild and sub-tropical climates, especially on sloped land, forests, and coastlines.
How to Grow
These shrubs require slightly more maintenance during the first 1-3 years of life. After that, it’s just regular maintenance, including pruning, pest scouting, watering, and fertilizing. It’s also very forgiving, even after neglect.
Light
Placing this plant in the shade can hinder flowering and overall health.
Mock orange prefers full sun and lots of open air. If grown in a shady spot, it may not flower vigorously. The best part about this plant is the fragrant blooms, so you don’t want to miss out on this feature.
Protect your plant from extreme heat and sun with shade cloth or move it into a shadier area if it lives in a container.
Water
Philadelphus coronarius becomes drought-resistant once well-established.
New plants and transplants should be watered consistently and planted in well-draining soil. Keep your eye on the moisture level during drought conditions and water as needed. They will not react well to being overwatered. Diseases may present themselves during this time.
Adding compost or a berm around the base of the plant will help the soil retain moisture. Once well-established, it is drought resistant.
Soil
Mock orange is adaptable to various soil types, including sandy, loamy, and clay soils.
These shrubs prefer well-draining soil with a pH of 4.0-7.0. However, it can handle higher pH and adapts to sandy, loamy, and clay soils.
Temperature and Humidity
To safeguard the roots during winter chills, provide water and apply mulch around the base.
Most weather patterns that happen in zones 3-8 pose no problem. No special treatment is necessary to protect from the cold or frost. Humidity doesn’t typically cause any issues, except the chance of disease may increase.
Before winter, water and add mulch around the base to protect the roots throughout the cold season.
Fun fact: The warmer the weather, the stronger the scent of the blooms.
Fertilizing
Apply the fertilizer during spring when tending to your other garden plants.
A slow-release feed is recommended, as these plants are not heavy feeders. Fertilize at the same time you apply general fertilizer on other plants in your garden, preferably in the spring. A single application should last the whole season if your plant is healthy. Follow the application instructions for whichever product you choose.
Pruning
Perform pruning to maintain the health of your plant, but remember it blooms on old wood.
Pruning should be done annually, whether your plant bloomed or not, to keep it healthy. Do this in May or June just after blooming so you don’t accidentally prune next year’s flowers. Like lilacs, rhododendrons, and forsythia, mock orange blooms on last year’s wood, so you don’t want to remove any of these during your pruning session.
Some growers recommend cutting the two or three largest canes down to the ground in the spring while pruning to help invigorate mature plants. This is called “renewal pruning” and should not be done on young plants still becoming established.
If you have an overgrown shrub, prune back about a third each year over the next three years to rejuvenate it. When doing this rejuvenation pruning, cut back the oldest stems to the ground each year, leaving the younger growth from that season, but do not remove all old wood. Flowering may suffer slightly, but this hard pruning is necessary in the long run to bring it back to peak performance.
Propagation
You can propagate in many ways, including taking cuttings in the summer or fall, starting them seed, dividing, planting pruned suckers, or layering.
Cuttings
If you opt for summer cuttings, ensure that blooming has already occurred.
To create new plants, you need a clean, sharp knife, a jar with water, potting soil, and rooting hormone. You can take cuttings from the shrub during the summer when leaves are still present, called softwood cuttings, or in the off-season, called hardwood cuttings. If you take cuttings during the summer, be sure blooming has already occurred.
How to take both softwood and hardwood cuttings:
- Cut a 3-inch long stem with some leaves remaining on the tip.
- Scrape off the bark and place it in clean water. This will prevent the cuttings from drying out as you continue to work.
- Once you have taken the cuttings you’d like, individually remove each cutting from the water, shake them off, and dip them in rooting hormone.
- Then, take a container filled with potting soil and make a slender hole deep enough to fit the cutting.
- Continue this process for each cutting.
- Water them gently and place them in a shady spot. You can cover them with plastic to help maintain moisture, but it’s optional.
Pro tip: The cuttings are very forgiving, so you can stick them together in clumps in a container while they grow. Allow these to grow until the following season before transplanting them into the ground.
Growing from Seed
Starting from seed is an alternative to buying or propagating from cuttings or suckers.
While most gardeners buy plants or create new ones from cuttings or suckers, starting from seed is an option. Stratify seeds for a few weeks in the refrigerator on a damp paper towel before sowing. Don’t overwet the towel. Just add enough to moisten the seeds.
When you’re ready to sow, add potting mix, some compost, and some sand to a container. Alternatively, you can just sow seeds in perlite or vermiculite. Optionally, you can add a little slow-release fertilizer to the mix.
Sow the seeds about ½ inch down into the soil. Do not cover them, as they require light to germinate. Water gently and keep them warm. They should germinate within two weeks. The initial growth stages are fairly slow. Seedlings should be ready to move into a larger container in about two months.
Division
Ensure that you preserve as many roots as possible during the separation process.
While the tree is dormant in fall or winter, dig up the root ball with a shovel and separate the clumps of roots and stem. Keep as much of the roots intact when splitting them up. Now, you can either replant, pot them up to give away to friends and family, or relocate your shrubs.
Treat the main plant you split as a new transplant and give it some extra love after the division as it recuperates. Flowering may be affected during the following bloom period, but they will fully recover.
Planting Suckers
A sucker is fresh, new growth that emerges between a leaf and the primary stem of a plant.
During your annual pruning session, remove suckers. A sucker is new growth that appears between a leaf and the main growing stem of any plant.
However, if you hope to propagate using suckers, leave a few on in the spring and snip them off in the winter when the plant has gone dormant. Pot them up like you would with a fresh cutting, as described above.
Layering
The layering propagation technique uses a branch that remains attached to the parent plant.
Air layering, or layering, is a propagation technique that utilizes a branch of a plant still connected to the mother plant. This only works if you have a decent amount of space for propagation, as the branch you select will be the stem of the new plant.
How to layer:
- Select a low-growing, healthy branch.
- Bury it with soil except for the top 6-12 inches. There should be greenery visible above the soil surface.
- Feed as necessary and keep it water until new roots form. Stake if necessary.
- Six to eight feet between these shrubs should allow for proper growth, ample airflow, and nutrients.
Creating a new plant this way takes 6-12 months, depending on conditions. The new plant will be an exact clone of the mother plant.
Planting
Provide ample watering until it establishes itself, then observe its growth.
If you’ve purchased plants from a local nursery or your suckers have grown large enough to be transplanted, map out where they will be in your garden. Remember, leave six to eight feet in between plants. Gather your transplanting supplies and head out.
Dig a hole large enough, about twice the size of the root ball. Set it in the hole, surround it with soil, and tamp it down. If you’re transplanting in the spring, do your annual feed now and water it to settle the soil around the root system. Water it amply until it becomes established, then watch it grow!
Location
The mock orange thrives on sloped terrain, aiding in soil erosion control.
Due to the captivating jasmine-like fragrance, many growers plant as close to their home or patio as possible. Imagine the sweet orange-perfumed air blowing in on a breezy summer day.
However, if you need some height in your perennial garden, pop one along the back edge for interest and year-round greenery. They also grow very well on sloped land, helping to reduce soil erosion, and also look great in the back of a cottage garden.
Popular Varieties
You can choose from climbing, dwarf, and standard-size versions. There’s something for everyone’s landscaping needs. Here are just a few options.
‘Belle Etoile’
The flower’s center carries a subtle purple hue, adding a touch of intrigue.
Meaning “beautiful star” in French, this cultivar is sure to impress. Its flowers are larger than others, and it blooms longer, giving you more time to enjoy the intense fragrance it offers. The center of the flower is tinged purple, making it slightly more interesting than some others.
At full maturity, it will be about five to six feet tall, which will take 5 to 10 years to reach.
Philadelphus x Virginalis
This cultivar thrives along the coast, enduring strong winds and salty conditions.
This hybrid, commonly referred to as the virginal mock orange, is considered a “climber” because as it’s growing to its 10-foot mature height, it tends to get leggy. It can be pruned to control the direction of its growth.
Philadelphus x virginalis does well on the coast, tolerating high winds and salty regions. As with other non-hybridized cultivars, this hybrid blooms on old wood. The flowers start out in a lovely cupped form and gradually unfurl as they mature.
‘Aureus’
To extend the duration of its cheerful appearance, consider pruning right after the flowers have faded.
Unlike other cultivars, Philadelphus coronarius ‘Aureus’ features bright, bold yellow leaves in the spring that change to green with age. If you prune immediately after the flower blooms fade, this may encourage a flush of new yellow leaves, giving you more time to enjoy its cheerfulness.
It’s considered medium in height, growing to 6-8 feet tall at full maturity, and was the recipient of the Award of Garden Merit of the Royal Horticultural Society.
‘Miniature Snowflake’
‘Miniature Snowflake’ is known for its greater disease resistance and beautiful double white flowers.
This compact cultivar only grows to be about 3 feet tall, so if you don’t have much space to play around with, this is a great option for you.
It seems to be more disease-resistant than some other cultivars and features double white flower blooms.
Common Problems
Although fairly resistant to pests and diseases, there’s always a risk.
Pests
Early scouting for pests is essential to manage them effectively.
There are not many pests that threaten mock orange, but keep an eye out for aphids, spider mites, and black scale.
How to prevent pests:
- Insecticidal soap, a heavy water stream, and diatomaceous earth may help with aphid infestations.
- Regular pruning to open up your plant and spraying neem oil will help prevent infestations of black scale.
- For biological control, attract parasitoid wasps.
Be sure to scout early for pests to keep them in check.
Diseases
To prevent diseases, ensure adequate plant spacing for improved air circulation.
This species is relatively disease-resistant. However, if you experience heavy spring rain, your shrub may be at risk of powdery mildew, bacterial blight, or brown spot.
Several different fungi cause powdery mildew and can be brought on during wet, humid spells. Bacterial blight is caused by bacteria that can overwinter in your soil and be flared up by excessive spring rain.
How to prevent disease:
- Space out plants to allow for proper airflow
- Remove infected branches immediately
- Water at the base and do not overwater
Key Takeaways
Choose a suitable cultivar for your soil type and available space to ensure successful growth.
- Select the right cultivar for your soil type and the space you want to fill.
- Plant in full sun and well-draining soil.
- Water at the base in extended periods of drought, but do not over-water.
- Prune annually after blooming has occurred in the summer, but don’t remove all the old wood as it buds on old wood the next year.
- Feed with a general fertilizer in early spring.
Frequently Asked Questions
Plant alongside forsythia, lilacs, and witch hazel to form a hedgerow. Space appropriately. Alternatively, plant along the back of a perennial flower patch. They aren’t heavy feeders, so as long as you prune to keep from shading out other plants, they make great companions.
This may be a sign of overwatering. Make a watering schedule and adjust it as needed, leaving more time in between each watering session. You don’t want the roots to become water-logged.
As long as your shrub is healthy and you regularly prune it, it should grow about two feet per year.
Improper pruning and over-fertilizing may be the culprit. If your shrub is overgrown, it focuses on new growth and keeping itself healthy instead of flowering. Prune every year after blooming to keep your shrub in tip-top shape for flowering the next year.
Be careful when feeding surrounding areas, as too much nitrogen may cause your tree not to bloom. Soil test if you’re unsure what’s going on and adjust accordingly.
Consider the height of the cultivar and the space you want to fill. If you don’t have a location that receives full sun, mock orange may not be ideal for your space. Although it can survive in shady areas, it won’t thrive and may not flower, which is the best part about this plant!
Final Thoughts
Mock orange is a beautiful, underrated option for hedgerows, patios, and perennial gardens. You simply can’t beat the sweet-smelling fragrance its summer blooms emit, and during the remainder of the year, it makes a lovely, dark green backdrop for the rest of your showy garden flowers.
