Mock Orange (Philadelphus) – The Complete Guide

The beguiling fragrance announces the presence of the mock orange from afar. Its concentrated flowering creates a picturesque scenario as a majestic solitary or lush hedge.

The following answers to common questions convey how uncomplicated the opulent ornamental shrub proves to be in cultivation.

Planting Mock Orange

Plant a mock orange in the fall in a sunny to partial shade location. While you weed and loosen the garden soil, soak the still potted root ball with water in a bucket.

To allow the powerful heart root system to spread unhindered, the planting pit should have twice the volume of the root ball.

Proceed as follows to plant a mock orange:

  • Enrich the excavation with bark humus, compost, horn shavings, or horse manure.
  • Pot out the plant, place it in the center, surround it with soil, press it down and water it.
  • Spread a layer of mulch with leaves, grass clippings or bark mulch.

Make sure to maintain the previous planting depth if possible. Finally, shorten the shoots by one-third to encourage lush branching.

Care Tips

Mock orange is relatively easy to care for. The straightforward care program presents no hurdles even for novice amateur gardeners.

Here’s how to care for mock orange properly:

  • Water regularly in the planting year, later only during summer drought.
  • Start fertilizing with compost in March to get the growth going.
  • Perform light pruning immediately after flowering.
  • Perform rejuvenation pruning preferably in autumn and winter, during the foliage-free period.

Light winter protection is advisable in the year of planting, as frost hardiness only builds up over time.

To do this, before the first frost, spread a thick layer of autumn leaves on the root disc. Then, fix the leaves layer with fir fronds.

Which Location is Suitable for Mock Orange?

The undemanding nature of the plant is reflected not least in its wide range of locations. The mock orange thrives tirelessly in all sunny to semi-shady locations with normal garden soil.

Ideally, the soil should be humus-rich, nutrient-rich, fresh, and, above all, well-drained. Where these ideal conditions are not present, soil additives provide compensation.

You should optimize excessively dry, lean soil with compost, bark humus, or horse manure. Loosen clayey soil with a tendency to compact with quartz sand, fine chippings, or lava granules.

Only from a location with impending waterlogging, do we strongly advise against the cultivation of mock orange.

When is Flowering Time for Mock Orange?

The multifaceted genus of mock orange (Philadelphus) gifts us with species and varieties that bloom at different times.

If you can’t get enough of the stunning blooms and enticing fragrance, combine the hybrids and species tactically for an extra-long blooming season.

The following suggestions may serve your inspiration:

  • Sweet mock orange (Philadelphus coronarius): Blooms from May to June.
  • Fragrant mock orange (Philadelphus x virginalis): Blooming from late May to mid-June.
  • Mock orange ‘Girandole’ (Philadelphus x virginalis ‘Girandole’): Blooming from June to July.

Although a mock orange per se does not have the potential for repeat blooming, efforts are sometimes rewarded nonetheless.

Immediately after the first flush of flowers, cut out any that have wilted and add a little compost to the root disc.

Pruning Mock Orange Properly

Although the flowering period extends into the summer, the mock orange is not treated as a summer bloomer when it comes to the topiary.

In fact, like a spring bloomer, the shrub blooms on previous year’s wood. Thus, pruning in early spring will deprive the plant of its already established buds.

Consequently, you should shorten excessively long shoots at the end of the flowering period.

For comprehensive rejuvenation pruning, on the other hand, choose a frost-free day in late winter by cutting all branches to 12 inches (30 cm) growth height.

This measure is carried out at the expense of this year’s flowering but is rewarded with vital and lush new shoots. During the deciduous period, thanks to this prudence, you reduce the stress for a mock orange to a minimum.

At the same time, take this opportunity to thoroughly thin out the shrub by removing dead wood, stunted, diseased and frostbitten branches at the base.

Every 2 to 3 years, completely cut out over-aged wood. You can recognize this by the darker and cracked bark.

Watering Mock Oranges

While freshly planted mock oranges require a regular supply of water, the need for watering decreases as they age.

During the first few months, keep the soil consistently moist without allowing waterlogging to form. This is especially true after a spring planting.

In later years, water the flowering shrub whenever natural rainfall is insufficient.

Fertilizing Mock Orange Properly

Starter fertilization in March stimulates growth and willingness to bloom. Treat your mock orange to a portion of compost and horn shavings, nettle manure, horse manure, or guano pellets.

Since the ornamental shrub naturally has vehement vigor, it will take care of itself for the rest of the season through its vigorous root system.

Overwintering Mock Oranges

An adult mock orange is completely hardy and will make it through the cold season in good health without any horticultural measures.

Since frost hardiness gradually builds upon young plants, we recommend light winter protection during the planting year.

To do this, cover the root disc with a layer of grass clippings, autumn leaves, or coniferous twigs. The already established buds should receive a cover of jute ribbons or garden fleece.

Propagating Mock Orange

For mock oranges, propagation by cuttings has proved excellent in practice. Here’s how easy it is to propagate:

  • In June, cut semi-woody head cuttings with a length of 4-6 inches (10-15 cm).
  • Defoliate in the lower part so that at least 1 pair of leaves remains in the tip.
  • Fill small pots with lean substrate to insert the cuttings by two-thirds.
  • Water them, put a transparent cover over them and let them root in a semi-shaded location.

Keep your cuttings constantly moist and keep them out of bright sunlight. Fresh sprouts will signal successful rooting.

By fall, more than 50 percent of the cuttings will have developed into vigorous young plants.

Mock Orange in a Pot

Because of their expansive heart-root system, mock oranges rarely feel comfortable in pots. This circumstance applies equally to mighty sweet mock oranges with a height of up to 10 ft (3 m) as well as to the compact hybrids with a growth height of up to 5 ft (1.5 m).

Even with optimal water and nutrient supply, a mock orange in a container usually falls far short of expectations in terms of growth and abundance of flowers.

Is Mock Orange Poisonous?

The toxicity of mock oranges is a controversial topic among amateur gardeners. We wanted to know exactly and asked botanists at a university.

The result is that so far, no investigation has been able to prove a toxic content so that there can be no question of even marginal toxicity. Thus, you may also enjoy the magnificent ornamental shrubs in the family garden.