Cornus controversa - Wedding Cake Tree and Cornus alternifolia: Planting and Care

Botany and description

Cornus controversa and Cornus alternifolia are two species of dogwoods with a tiered branching habit. Both belong to the subgenus Swida, like the well-known dogwoods with colourful stems: Cornus alba, Cornus sanguinea and Cornus sericea. These are dogwoods whose flowers lack an involucre of bracts. In older botany books, you may still find the names Swida controversa and Swida alternifolia.

Cornus controversa

The Cornus controversa or Pagoda Dogwood (also called Giant Dogwood) is a tree from the Cornaceae family. Its natural range extends from Japan to China, through Korea, India, Nepal, Bhutan and Taiwan. The natural habitat of Cornus controversa is mixed forests of deciduous and coniferous trees.

Its habit is quite characteristic: tiered, meaning in horizontal layers. Its branches grow almost horizontally, which earned it its common name of Pagoda Tree or Pagoda Dogwood. It is a tree with smooth bark that spreads over the years, developing a broad, pyramidal shape. The bark turns greyish with age, but young shoots are bright red.

Its foliage is deciduous and, surprisingly for a dogwood, alternate. Only this species and Cornus alternifolia have alternate leaves, while other species in the genus (C. alba, C. sanguinea, C. sericea, C. florida, C. kousa…) have opposite leaves. Cornus alternifolia, although smaller, is botanically similar to Cornus controversa, and both are cultivated in the same way. Each leaf has 5 to 9 longitudinal veins. The leaves are ovate with a pointed tip and angular base. The foliage is a beautiful glossy green on top and light grey-blue on the underside. The foliage turns fiery shades in autumn. Some cultivars have variegated leaves, like the now famous Cornus controversa ‘Variegata’.

Flowering occurs in spring from May to June. The flowers form wide, flat corymbs of numerous tiny cream-white star-shaped flowers with four petals. The fruits are small spherical blue-black drupes containing a small stone.

The absolute elegance of Cornus controversa ‘Variegata’, the colourful autumn foliage (©Wendy Cutler), and the foliage of the species type

Cornus alternifolia

Cornus alternifolia or Alternate-leaf Dogwood, native to northeastern North America, is more of a large bush and differs from Cornus controversa in a few ways: the young shoots are red-purple, sometimes almost black. The foliage is less rounded and more tapered than that of the Giant Dogwood. Moreover, it turns a very beautiful colour in autumn, changing from yellow (creating a striking contrast with the dark stems) to matte violet-burgundy later on.

The flowering, similar to that of Cornus controversa, occurs in late May or early June, after the foliage appears. The inflorescences are flat corymbs made up of numerous small cream-white flowers, positioned above the foliage. The fruit is a small blue-black drupe appreciated by birds.

The size of the Alternate-leaf Dogwood is also more compact, making it interesting for small gardens: about 5 m in all directions at maturity for the species type, and much less for the varieties. There are indeed some beautifully coloured varieties, such as ‘Golden Shadows’ with golden-yellow variegated leaves or ‘Pinky Spots’ with tricolour foliage: green, white and pink.

On the left, silhouette of Cornus alternifolia ‘Argentea’ (© Peganum), on the right foliage of Cornus alternifolia type

Our favourite varieties

Cornus controversa

Cornus alternifolia

Cornus controversa - Giant Dogwood

Cornus controversa, the type species also known as the Wedding Cake Tree, is one of the largest in the genus. Forming a true small tree, it charms with its remarkable silhouette, with tiered branches creating a living sculpture that becomes the garden's focal point.

• Flowering time July, August
• Height at maturity 12 m

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Cornus controversa Pagoda - Giant Dogwood

Cornus controversa 'Pagoda' has a more pronounced tiered habit than the type, giving it an exceptionally graphic silhouette.

• Flowering time June, July
• Height at maturity 12 m

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Cornus controversa Variegata - Giant Dogwood

Cornus controversa 'Variegata' is adorned with glossy leaves, broadly variegated with cream, which in summer become covered in snow-like, fragrant clusters of flattened inflorescences.

• Flowering time July, August
• Height at maturity 7 m

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Cornus alternifolia - Pagoda Dogwood

Cornus alternifolia, the type species also known as the Alternate-leaf Dogwood, forms a bush with a naturally interesting habit, featuring tiered and horizontal branches and a flattened crown that give it an attractive texture in the garden. It bears ample, dense foliage of a fairly dark green with a glossy finish, sometimes turning beautiful autumn colours depending on the soil.

• Flowering time June, July
• Height at maturity 5 m

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Cornus alternifolia Golden Shadows - Pagoda Dogwood

Cornus alternifolia 'Golden Shadows' forms a graceful bush, with tiered and horizontal branches covered in gold-variegated foliage that changes, taking on fantastic hues through the seasons. Margined with gold, it is tinged with red-orange in spring, greener in summer, then purple in autumn.

• Flowering time June, July
• Height at maturity 3 m

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Cornus alternifolia Pinky Spot Minpinky - Pagoda Dogwood

Cornus alternifolia 'Pinky Spots' forms a well-branched yet graceful bush, with tiered and horizontal branches, and bears foliage variegated with creamy white and pink on a green background, particularly colourful in spring. It becomes greener in summer, then purple in autumn.

• Flowering time August, September
• Height at maturity 3,50 m

See the product sheet

Cornus alternifolia Argentea - Pagoda Dogwood

Cornus alternifolia 'Argentea' has extraordinary foliage, variegated with white, turning red in autumn, dressing its tiered silhouette first in snow then in embers.

• Flowering time June, July
• Height at maturity 3 m

See the product sheet

How to plant a Cornus controversa?

Where to Plant?

The Cornus controversa and Cornus alternifolia are relatively undemanding when it comes to soil. The earth should be rich, non-calcareous, and not too heavy. The ground must remain moist year-round, as overly dry conditions will stunt the tree’s growth. It tolerates clay soils, but the soil must always be well-drained.

In terms of exposure, these dogwoods thrive best in partial shade, in a woodland-like setting. However, the Cornus controversa can grow in full sun if it is not too scorching.

When to Plant?

Planting can be done from March to April, or even better in autumn: from October to November. Autumn planting allows your dogwood to develop a strong root system for the coming year.

Cornus controversa ‘Variegata’ and Ophiopogon planiscapus ‘Nigrescens’

How to Plant?

• Soak your potted dogwood in a large bucket of water for several minutes to rehydrate the root ball.
• Dig a hole twice as deep and twice as wide as the root ball. Keep the excavated soil and loosen it.
• Loosen the soil at the bottom of the hole with a hoe or pickaxe.
• If your soil is not well-drained (very compact), mix gravel into the excavated soil. Avoid Rhine sand, which can sometimes do more harm than good in heavy clay soils, and skip gravel at the bottom of the hole—this creates a “sump” filled with water right at root level, which is also undesirable. Compost will also improve soil texture.
• Remove the tree from its pot and check the quality of the roots. Trim any damaged or rotten roots. Don’t hesitate to untangle the root ball and remove most of the potting soil, especially for autumn planting.
• Add several handfuls of well-rotted compost to the planting hole.
• Prepare a root slurry (pralin): a few handfuls of soil, a generous handful of decomposed manure, and rainwater until it forms a sticky mud. Dip the tree’s roots into this mixture. The slurry provides everything the roots need to kickstart growth.
• Place your tree in the hole, hold it upright, and backfill with the excavated soil.
• Ensure the collar of the tree (where roots meet the trunk) is not buried. Planting on a slight mound is ideal. Keeping the collar above ground allows lateral roots to spread and “breathe.” The tree is less prone to disease, better anchored, and grows faster.
• Gently firm the soil around the tree without damaging the roots and create a shallow basin to retain water at the base.
• Water thoroughly with ten litres of water. This step is crucial to eliminate air pockets between roots and soil.
• A good mulch of dead leaves or, even better, planting ground-cover perennials will keep the soil moist year-round.

Caring for Your Cornus controversa (Wedding Cake Tree)

Watering

The soil should not be dry in summer or waterlogged in winter! Flowering dogwoods are sensitive to water stress. We recommend using mulching to maintain moisture and also to protect the roots from winter harshness.

Water regularly during the first year, about one watering can per week. After that, watering is unnecessary except in regions where drought is common.

Pruning

No pruning is necessary. Cleaning is limited to removing dead branches in March. You may optionally remove branches that cross or appear poorly positioned (which is rare with this type of tree or bush). Do not attempt to restrict its growth in width and height, as this will spoil its shape. So think carefully about the size your dogwood can reach once mature.

Possible diseases and pests

The Cornus controversa can be affected by anthracnose (or black spot disease), a fungal disease. Anthracnose appears as brownish spots edged with purple, necrosis on the leaves and young shoots. These fungi take advantage of wounds to enter, so do not prune. Simply remove dead wood. Avoid watering the foliage and burn leaves showing signs of anthracnose, including those that have fallen to the soil.

Powdery mildew (white mould) may also affect dogwoods. A white felting appears on the leaves, which then become distorted and dry out. This disease can occur in humid conditions with significant day-night temperature variations. Ensuring good air circulation between plants helps prevent fungal infection.

Propagating a Cornus controversa

By sowing

Sowing is unpredictable, as few seeds are fertile and, in any case, sowing will rarely produce the same cultivar as the parent plant: more often than not, the seedlings revert to the typical Cornus controversa (which is also magnificent!). Harvest the seeds from ripe fruits in October, soak them for 24 hours, then sow them in pots with well-draining soil. Keep the pots in a cold frame and only bring them out the following spring. Place your pots in partial shade and keep the soil moist but not waterlogged. Transplant your young plants individually once they have four leaves, then plant them in the ground the following autumn.

By grafting

This is the method preferred by professionals. Shield grafting in November yields good results when using a typical Cornus controversa rootstock.

Warning! Some graft Cornus controversa and C. alternifolia onto other dogwoods, which are cheaper to produce and very vigorous (C. alba, C. sanguinea, C. amomum…). This solution is economical, but… often the rootstock produces suckers from the base, which makes the tree unsightly and obscures its tiered structure. In such cases, these suckers must be pruned back relentlessly. Beware of Cornus controversa and Cornus alternifolia sold at suspiciously low prices!

→ Learn more about dogwood propagation in our tutorial!

How to pair the Pagoda Dogwood?

If you’ve planted your Cornus controversa ‘Variegata’ as a standalone feature in your garden, for example at the centre of a short grass meadow, let’s keep the accompaniment simple. A few understated perennial groundcover plants will be perfect at its base: Pachysandras, Brunneras, Ajugas, Geranium macrorrhizum… and why not, if your soil is sufficiently moist, the Cornus canadensis.

But this type of dogwood also makes a striking statement in a modern, minimalist garden style alongside some ornamental grasses, such as Calamagrostis acutiflora ‘Karl Foerster’, Helictotrichon sempervirens or Carex comans ‘Bronze Form’.

As for the Pagoda Dogwood, despite its American origins, this small tree pairs beautifully with Asian plants in a Japanese-inspired garden style. A Cornus alternifolia ‘Golden Shadow’ will find good company with an Acer palmatum ‘Butterfly’, a Rhododendron ponticum ‘Variegatum’ with variegated leaves and mauve flowers (which will contrast beautifully with the yellow foliage of the dogwood) and a Pieris japonica ‘Forest Flame’. A few ferns will complete the picture.

Cornus alternifolia ‘Argentea’, Pieris japonica ‘Forest Flame’, Acer palmatum ‘Butterfly’, and Rhododendron ponticum ‘Variegatum’

Anecdotes and possible remarks

• The Pagoda Dogwood is called “Table Dogwood” in English;
• The species name “controversa” means “controversial” or “divergent” due to its branches that increasingly spread away from the trunk over the years;
• Its hard wood (as with all dogwoods!) is still used today in Japan to make kitchen utensils, small sculptures, or sometimes the bases of traditional shoes