Improved varieties of reliable and durable mock orange (Philadephus cvs.) are wowing gardeners with their masses of showy, white, single or double, orange-blossom-scented blooms that flower for about three weeks in late spring, from mid-May to early June.
Recent introductions produce larger blooms than older types, with several others being more compact and shorter (around one metre tall), making them versatile enough to grow in small spaces, large containers or the front of a border.
Many of the new offerings are fast growing and form a dense mound of gently cascading branches. They tolerate heat, drought and cold, too.
Younger plants often have red, chestnut brown or orange bark, which starts to peel beautifully as the shrub matures to reveal a brown or tan colour underneath. Stems can be easily thinned out (the shrub is quite forgiving of exuberant pruning) to show off these colourful and textured branches.
Mock orange has no serious pest or disease problems. There is some susceptibility to aphids and leaf miners, the latter being more of a nuisance than a threat. Aphids, meanwhile, secrete sticky honeydew that can attract sooty mould, which blocks sunlight from the leaves. This inhibits food production and causes the plant’s health to decline, which makes it more vulnerable to other pests and disease.
- Plant balled and burlapped shrubs in spring and container-grown ones in summer (water well) or fall.
- Grow in full sun (for best flowering) to part shade.
- Prefers a well-drained, moisture-retentive, organic soil, but tolerates a wide range of soils, except those that are waterlogged.
- Mulch newly planted shrubs with a five-centimetre layer of shredded bark or small wood chips around the root zone in the spring and fall to suppress weeds and conserve moisture.
- Top-dress shrubs in early spring with a 2.5-centimetre layer of compost and an organic mulch (five centimetres deep) applied overtop.
- Mock oranges bloom on the previous year’s wood, so prune immediately after flowering.
- Thin out crowded branches to promote good air circulation and allow light to penetrate into the centre of the shrub. Prune to shape leggy specimens.
- Rejuvenate overgrown mock oranges by removing one-quarter to a third or more of the oldest branches, right down to soil level. Prune in early summer right after flowering. For taller cultivars, shorten the branches by a third to reduce the height of next year’s blooms.
- Dislodge any aphids with a forceful stream of water.
- Propagate by taking softwood cuttings in summer or hardwood cuttings in winter.