How to grow Exochorda

Native to China and central Asia there are about 5 species of exochorda with only 3 in common cultivation worldwide.

Commonly called ‘The Pearl Bush’ due to its subtly fragrant 5 petalled pristine white flowers in racemes resembling a string of pearls from between every leaf bud in spring or summer, borne on last years growth.

I kid you not the words ‘flower to death’ can be used on this genus as the plant is classed as relatively short lived -25 years- often producing so much flower the plant can suffer. Visibility you’ll never forget seeing an exochorda in full flower. – Similar to a spiraea but with much larger flowers.

Within the Rosaceae family, exochorda are bushy deciduous shrubs with oval pale green leaves which turn shades of yellow and orange in autumn before fall. Plants range in height from approx. 1m to 4m in height dependent upon variety.

After flowering a fruit called a coccetum can be produced which looks like an inedible star fruit. Consisting of five fused carpels that split open to release flattened seeds. The placentary cords external to the carpels give the genus its name, ‘exo’ meaning outside in Greek and ‘chorde’ meaning a cord

Zantedeschia is a genus of flowering plants from the family Araceae and is native to southern Africa. With a rich history dating back to the Ancient Romans, these deciduous or semi-evergreen perennials have been used as a symbol of celebration. Zantedeschia was Named after Professor Giovanni Zantedeschia, an Italian botanist.

There are two main forms of Zantedeschia: hardy and tender. Hardy forms of the plant can be grown outdoors, enjoy moist soil and full sun or partially shaded conditions - these are known as Arum lilies. Tender forms of Zantedeschia prefer being grown in containers or pots and should be brought inside over the winter - these are known as Calla lilies.

With tuberous flora in all colours from whites, yellows and oranges to deep reds and purples, Zantedeschias are not to be overlooked in any garden, as long as they have sufficient sunlight to grow in.

Ready to learn more about growing Zantedeschia? Read on for all there is to know...

Key Information

Soil pH

Position

Hardiness

Here we list out the most popularly cultivated species and hybrids.

	Species	Common name
HARDY – cold winter (H6/ -15°C to -20°C) Grow anywhere in the UK	Exochorda korolkowii	Pearl Bush
	Exochorda racemosa	Pearl Bush
	Exochorda serratifolia	Pearl Bush
	Exochorda x macrantha	Pearl Bush

Where & when to plant Exochorda

Position - Full Sun or Part Shade Sheltered location

Soil - Moist free drained humus-rich soil, acid – neutral -not chalk.

Flower - Spring or Summer

Hardiness - H6/ -15°C to -20°C

Exochorda can be planted all year around when purchased grown in pots. Bare rooted plants are best planted in late winter or early spring when the ground is not frozen or waterlogged.

If container grown plants are planted out during the active summer growing season make sure that they are watered regularly until the plant has settled into its new location. Water at soil level rather than the foliage.

Larger growing plants can be planted in the garden as a specimen whilst there are more compact varieties which can be planted in mixed borders or patio containers. Most exochorda prefer a little shelter from late spring frosts which can cause tip dieback that effects flowering.

Try growing as solo plants, garden borders, hedges and especially with more dwarf varieties such as Exochorda ‘Blushing Pearl’ in patio containers for a stunning display which can be moved into view when looking its floral best!

Plant in moist yet free draining soil that has a pH of 6 – 7. Exochorda will grow in most soil types (clay, sand, loam) except chalk which will be too alkaline.

How to plant Exochorda

For planting in the garden, dig the soil area removing any large stones and weeds and breaking up any lumps. Mix in some organic matter, ideally leaf mould, though manure or garden compost are also fine. Rake level and firm with your heels. Rake level again.
Water plants well and allow to drain before planting.
A good tip is to dig a hole twice the size of the root-ball. Fill with water and allow to drain before placing in the plant which is especially good for summer plantings.
Remove the plant from its pot placing the plant in the hole, ensuring the top of the root ball sits level with the surface of the soil. Too low and the plant may rot, too high and the roots can dry out. If bare root hold the plant at soil surface level allowing roots to dangle into the hole.
Backfill with soil and firm in gently with your foot.
Soak soil well with water.
Mulch around the base with well-rotted organic matter.

For planting in containers, first choose an appropriately sized pot around 5-7cm larger than the rootball of your plant (you’ll need to gradually increase the pot size every few years). Always ensure there are plenty of drainage holes in the bottom.
Use a good quality potting compost if you have it and mix with garden soil. Mix in some horticultural grit and, if not already present (check the labelling on the bag) some slow-release fertiliser granules.
Start by partially filling the pot with compost; enough so that when placed on it the upper surface of the root ball is about 3cm lower than the top of the pot.
Fill around the plant with compost, firming down with your fingers then adding a little more so it is held tight.
Pick up the container and lightly tap on the potting bench or ground a few times to help further settle the compost around the plant.
Soak well with water.
A mulch with horticultural grit will look attractive and help to prevent a ‘cap’ or crust forming on the top of the compost (something container plants can suffer due to the artificial nature of their watering).

What to plant with Exochorda

Outdoors, plant alongside plants with different shaped or coloured foliage as a contrast. Try Alstroemeria, Camellia, Ceanothus, Clematis, Ferns and Grasses, Hardy Geranium, Roses, Petunia, Tulip, Narcissus (Daffodil) and Viburnum.

Shop Ceanothus

Shop Syringa

Shop Viburnum

How to care for Exochorda

Pruning and Deadheading

Exochorda are easy care garden plants falling into RHS pruning Group 2. Prune immediately after flowering has finished.

Exochorda flower on previous season growth, so by pruning straight after flowering the plant has time to develop new shoots this year for flowering next summer.

Cut back flowered growth to strong young shoots lower down. Each year cut out up to 20 percent of ageing stems to near the base. Cut out any damaged or dead shoots back to their point of origin or to ground level.

Where there are many stems remove some to ground level to keep the bush open and avoid congestion.
Finally take out any weak, spindly or twiggy shoots right to the point of origin or to ground level so the plant concentrates its resources on strong new shoots that will bear the best flowers next summer.

Watering

Exochorda enjoy moist yet free drained soil. On planting outside, they benefit from a good watering in on planting and then regular soakings until established. After this they should need watering only in very hot, dry conditions. Allowing the top few centimetres to dry out between soakings is a good rule of thumb to avoid overwatering. To check this, wiggle your finger down into the soil until you hit a cool, damp bit.

Feeding

On healthy, fertile soil, a mulch of well-rotted organic matter (i.e., a layer of leaf mould, manure, or garden compost applied to the soil around the plant) should provide enough nutrients for your exochorda. This has the added benefit of suppressing weeds and locking in moisture. Mulch when planting, and then again each spring.

If you garden on poor soil or your exochorda looks in need of a boost, applying a granular general purpose feed to the surface of the soil and lightly working in can reap benefits. This is known as a top dress and should be done when you’re mulching in spring – first apply the feed, then cover with the mulch.

Container-grown plants are different as they rely solely on the gardener for nutrition. Get off to a flying start by making sure you use a good quality compost with slow-release granules mixed in. These generally provide nutrients for around 6 to 8 weeks, after which you’ll need to apply a liquid feed every 2-3 weeks until the end of the growing season (i.e., September-ish).

Remember to repot your exochorda every few years into a slightly larger pot using fresh compost. In-between, it’s worth removing the top few centimetres of compost each spring and replacing with a fresh mix of compost and slow-release granules.

Cold Protection

Exochorda are hardy garden plants and should not need any winter protection. Plants prefer a more sheltered location but grow well in exposed hedgerows too where other plants help provide shelter.

Pests and Diseases

Exochorda are generally considered problem-free, yet on rare occasions can suffer from honey fungus. This is a common disease which effects the base of the plant where visible signs of white mould can be seen.

How to propagate Exochorda

The recommended way to propagate exochorda is by softwood cuttings.

In late spring to early summer collect some branches containing tender new season growth early in the day..
Choose a non flowering tender young shoot which is approximately 5-10cm long from its tip.
Using a sharp knife trim below a node (leaf joint) Remove the lower sets of leaves leaving 2 to 4 leaves at the top.
Pinch out the soft tip to just above a leaf joint and dip the base into rooting hormone powder or liquid.
In a ready watered and drained pot level filled and lightly firmed with good quality new compost, make a hole for the cutting with a dibber. Insert the base of the cutting until the first set of leaves are just above the surface.
In a 9cm pot you can put 3 cuttings in a triangular formation making sure the leaves are well within the edges of the pot.
Cover with a plastic sandwich- like-bag to form a mini propagator is a good idea for the first few weeks. Hold the bag in place on the pot with an elastic band or string. Ensure the bag is stiff enough to hold upright above the plants foliage. The plastic bag holds in moisture keeping the humidity high which reduces the rate of water loss from the cutting, increasing the success rate of propagation.
Place the pot on a saucer away from direct sunlight, yet in a light area that is around 18-24^o
At least twice a week remove the bag to allow some ventilation to the cuttings for 15 minutes. Check the soil surface feels damp.
Rooting takes 2 to 4 weeks. Gently pull on one of the cuttings if it shows resistance then it is likely roots are forming. The bag can now be removed for longer periods of time gradually acclimatising the cuttings to their surroundings. (Hardening Off)
Remove any dead or decaying material regularly.
Once hardened off for 2 -4 weeks the cuttings should be ready for potting on individually. Carefully remove the plants from the pot as one root ball. Checking for signs of good rooting - if not ready leave to develop for few more weeks. Carefully separate each cutting ensuring a good portion of root is kept intact potting on into individual 9cm pots. Water well and leave to develop in a light sheltered environment until established.

Propagation by Seed.

Ensure the flattened seeds are clean and dry. Best sown in Autumn which will give the seeds a winter cold period to stratify the seedlings ready for spring growth.

Fill seed tray with good quality seed compost. Level and firm with the bae of another seed tray. Water well.
Carefully scatter the seeds across the compost surface of the tray
Cover the seed to their own depth with sand or grit.
Place the seed tray in a cool, light sheltered spot and keep moist. Protect against pests such as slugs, and mice.
Germination should take place in spring.
Once seedlings are large enough to handle they can be pricked out individually and grown on.

* Many plants carry Plant Breeders Rights and cannot be propagated for commercial purposes.

Common Exochorda questions

What do you feed exochorda?

Follow the instructions in the guide above on how to feed your exochorda.

Is exochorda a climber?

No exochirda is a free standing garden shrub or small tree.

Can I move exochorda?

Yes you can move a planted exochorda to a different location in the garden. Best time to move is in winter or very early spring, before new growth has begun. Ensure the ground is not waterlogged or frozen. Dig around the root ball – depending on the plants size. We would recommend at least a diameter of a 3^rd of its height. Dig around and under gently easing the plant out of the location. Move to its selected site and follow the guide of how to plant above.

Is exochorda poisonous to dogs?

Exochorda does not have any reported toxic effects.

Is exochorda good for wildlife?

Yes exochorda does provide pollen for pollinators and its foliage provide shelter for insects.