Growing guide
How to grow philadelphus
Often you can smell the delicious scent of Philadelphus (mock orange) before you spy them in a garden. These medium to large shrubs produce masses of white blooms in early summer and are easy to grow, so why not see if you can make room for one in your garden.
Quick facts
- Heavily-scented flowers in early summer
- Medium to large shrubs
- Deciduous, loosing their leaves in winter
- Easy-to-grow in sun or light shade
- Grows well on most soils
- Prune after flowering
- Propagate by cuttings in early summer
All you need to know
What are Philadelphus?
These easy-to-grow shrubs produce a clusters of white flowers in early summer. These are last only a few week, but many scent the air, creating a lasting impression in early summer.
Choosing the right Philadelphus
The vast majority of Philadelphus are hardy so can be grown throughout the UK. As a result, the main choices come down to selecting a plant that will be the right size for your garden, as well as choosing a flower form you particularly like. If you go to a nursery or garden centre in early spring, you will often see the plants in bloom, which can be more helpful than looking for pictures in books or online as you can smell them too!Eventual size
The most important thing is to select a cultivar with an eventual size that'll suit your garden.- Large cultivars reach around 2.4m (8ft) tall so are suit the back of borders, or can be used as a substitute for a small tree in a tiny garden. A popular example is such as Philadephus 'Beauclerk'
- Medium height philadelphus, such as P 'Belle Etoile', that gets to around 1.5m (5ft). They are ideal to plant behind other summer-flowering shrubs such as roses or grown among tall perennial plants
- Small cultivars with compact and weeping habits include P. 'Manteau de Hermine' or P. maculatus 'Sweet Clare'. These are around 75cm (30in) tall and good at the front on a border or large container
Flowers and foliage
As far as the flower differences go, some are double or have coloured centres, but the overwhelming impression is of a profusion of white blooms. Choose one that appeals most.If you like coloured foliage, there is the golden form, P. coronarius 'Aureus' and a variegated P. coronarius 'Variegatus'
Top tip
Bear in mind that after their early summer glory, mock oranges revert to being backdrop plants - green and leafy shrubs, until they shed their leaves in autumn. While valuable in the chorus, it's probably no best to place them in a staring role in your garden, for example are a focal point.
Buying a philadelphus
These shrubs can be bought from garden centres and nurseries as container grown plants. They are normally for sale in 2-litre pots, but larger sizes are sometimes avaiable in garden centres and nurseries, and from online suppliers, with a larger choice available by mail order.Plants can sometimes be bought bare-root in the dormant season (winter), usually by mail order. These are ready for immediate potting up or planting out.
Buying: garden centre plants
Buying: trees and shrubs
When to plant
- Plant container-grown plants at any time of year, but they establish best when planted in autumn or spring
- Plant bare-root plants in the dormant season (winter) when the ground is not frozen or waterlogged. Alternatively pot up into a container to grow on
Where to plant
Choose a sunny or semi-shaded site in fertile, well-drained soil.- Avoid planting golden-leaved forms in full sun as it can damage foliage
- Check on the label for eventual width of the plant, to give plants enough room
- Also check eventual height when considering placement, as some are short and suitable for the front of the border, whereas a few are as tall as small trees
How to plant
Plant container-grown and bare-root Philadelphus as you would any shrub, by digging a hole deep enough to take the rootball, but wider. Improve the soil that goes back in around the sides of rootball with well-rotted compost or manure. Water in well and keep moist if you plant in spring and summer. Mulching newly planted shrubs will help retain moisture in the ground.If you're unsure, follow our step-by-step guide.

Planting shrubs
Trees and shrubs: planting
Feeding
A general-purpose fertiliser, such as a handful of Growmore per sq m (sq yd), can be applied in spring if your plant needs a boost or the plant is growing on poor soil.Mulching
Applying a mulch of organic matter is a good way to improve soil conditions and add some nutrients. It also keeps the weed competition down and preserves moisture in the soil.Mulching
Watering
Once established, a philadelphus shrub is unlikely to need watering unless your soil is very free-draining and there is a prolonged period of drought.Watering
Deadheading
Philadelphus don't need deadheading as they only flower once a year and removing the flowers doesn't improve the next flowering or promote growth in a noticeable way.Pruning young plants
Cut out any dead, diseased or damaged branches after flowering. If there's a branch that's crossing through the centre of the plant, you might want to prune that out too - that way you'll get an open shrub without congestion and branches that rub against each other.
Pruning established plants
Philadelphus are best pruned after flowering in summer. It's not vital every year, but it does promote development of new flowering wood.You do this simply by cutting back some older growth to new shoots lower down a branch and by thinning out from the base a few of the older stems entirely (limit yourself to removing one in five annually).
Shrubs: pruning early-flowering
Cuttings: softwood

Softwood cuttings
They can get aphid problems in ealy summer though, both greenfly and blackfly. You may notice these sap feeders when foliage starts to curl in response to their saliva. Interestingly philadelphus are one of the winter/spring hosts of the black bean aphid, the blackflies which can cover the tips of your broad beans a little later in the season. They don't have to be controlled and are usually tolerated.
If you're a member of the RHS, you can use our online Gardening Advice Service, via MyRHS, for any gardening queries and problems.

Discover philadelphus
Everything you need to know about choosing the right philadelphus for you
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