The stunning flowering dogwoods have been having a wonderful year

THIS has been an amazing year for flowering dogwoods – Cornus kousa and Cornus florida – with stunning displays throughout the region. When in bloom, they are impossible to ignore: the yellow-green flowers are fairly inconspicuous compared to the four elegant bracts that surround them – a stunning combination which can be seen from afar. Most flowering dogwoods have bright white/green-tinged to creamy white bracts that sometimes turn slightly pink as they age, but there are also some full on pinky-red varieties for those who crave some colour.

Cornus kousa is a small, deciduous tree or multi-stemmed shrub native to China, Japan and Korea, flowering from late spring until midsummer. It typically has an upright, vase-like habit but becomes more rounded and spreading as it matures. The bracts are pointed at the ends, giving them a slight star-like appearance. Cornus florida is superficially similar, but is native to eastern North America and northern Mexico. It flowers a few weeks earlier than Cornus kousa and the bracts are generally a little larger and more rounded. Both species have excellent autumn colour, especially if grown in a sunny spot. Cornus kousa has the advantage of flowering for longer and being more drought and disease tolerant.

Flowering dogwoods are fairly low maintenance once established and require little to no pruning. They prefer an organically rich sandy loam soil but can tolerate heavier soils as long as they are not waterlogged over winter and are mulched annually with well-rotted leaf mould or garden compost to help enrich the soil. Likewise, they will perform better if the soil is consistently moist during hot summers – a mulch will help retain moisture and keep the roots a bit cooler. A neutral to acid soil is best – composted pine needles also make a good mulch - though some can tolerate a mildly alkaline soil.

Choose a position sheltered from cold winds and preferably in full sun if you want more blooms, but dappled shade is also fine. The best blooms are produced the year after a prolonged hot summer, which ripens the wood. When planting new trees always ensure they are well watered over the summer. At Harlow Carr we are watering our new trees at least once a week during the hot, dry weather. Be generous: the water needs to make it down beyond the current roots to encourage them to grow outwards and downwards later on when they try to find water of their own. Keep an eye on them during their second summer as many young trees need a bit of extra help until they have a more established, far-reaching root system.

Whilst flowering dogwoods are hardy in the UK, young trees take a little time to catch up and during a cold spring it’s worth fleecing them overnight once they are in leaf and if a frost is predicted. This may require a bit of effort initially, but it will be worth it once you have a happy, mature tree that can fend for itself.

There are numerous cultivars from which to choose: if you are looking for a tree that will bloom sooner rather than later, it’s advisable to get one that has been grafted rather than grown from seed.

Cornus kousa var. chinensis is the Chinese variation of Cornus kousa and is considered superior to the straight species, with excellent vigour and flowering slightly earlier, typically with slightly larger bracts and fruit. It can eventually reach up to 8m with a spread of 5m, although this would take 20 to 50 years.

Notable cultivars include Cornus kousa ‘China Girl’ which can flower after just two or three years, compared to the straight species which can take 10 to 15 years. Bracts are creamy yellow. Cornus kousa ‘Milky Way’ produces an abundance of milky-white bracts. If it’s size you’re after, Cornus kousa ‘Greensleeves’ is a good choice.

Personally, I think the white bracts are more striking, but if you can’t do without some colour, the likes of Cornus florida f. rubra might hit the spot. We have an excellent specimen in the woodland at Harlow Carr; its graceful tiered habit is worthy of admiration.

If you don’t have space for a tree, but love the blooms, Cornus canadensis offers beautiful, low growing, herbaceous ground cover. It requires a moist, acid soil and dappled shade.

Finally, the Cornus I would love to see up close is Cornus florida subsp. Urbiniana, native to Mexico. Its unusual bracts are fused at the tip, making them form a delicate, twisted cage around the flower. It would be a beguiling addition to any garden.