Cornus

Cornus is a large and varied genus. For the purposes of this website, they can be divided into 3 groups.

• Flowering dogwoods producing showy floral bracts in summer:
  This page provides an over-view of this group. We have a fabulous and extensive collection, though our primary focus is on the cultivars of Cornus kousa which are the best adapted for the British climate. We also have a tremendous number of hybrids from them, some of which are Semi-Evergreen, as well as an increased number of fully Evergreen Cornus. Our range of American dogwood includes cultivars of the two species Cornus nuttallii and Cornus florida as well as some spectacular hybrids between them. There is such diversity within this group that there really is a cultivar of these wonderful plants to suit every situation!
  

• Layered shrubs and trees: 
  Specifically the cultivars of Cornus alternifolia and Cornus controversa.
  

• Large shrubs or small trees having globular clusters of bright yellow flowers in February:
  Specifically the cultivars of Cornus mas and Cornus officinalis.

The flowering dogwoods are an attractive group of plants that is not as widely known and planted in this country as they deserve to be. 

The attractive parts of the flower head are bracts, which are actually modified leaves, but which resemble petals. Four of these showy bracts surround the tiny true flowers in the centre. These bracts are white in all the main species, but there are now many pink cultivars too. Since they are bracts not flowers, they last longer; often starting green and star-like before expanding to a more rounded shape as the true flower opens. In some cultivars, the bracts then mature to pink; particularly so on bracts that are more exposed. Thus it is less evident on plants grown in a shady or woodland position. In an open, sunny position a colour gradient can often be seen across the bracts according to their exposure on the actual plant, with some cultivars turning almost completely pink as the bracts mature. 

Many cultivars of C. kousa also produce attractive fruit. These resemble big round strawberries and are indeed edible. Although I'm not a particular fan, it's good to know that they will do no harm to inquisitive fingers! I'm told that they make excellent jam or even wine. And if that wasn't enough, many of them also give lovely autumn foliage colour in shades of orange and red. The intensity of colour may be defined by the weather and growing conditions, with some cultivars colouring more reliably than others. 

We are often asked just for the straight species Cornus florida, C. kousa or C. nuttallii as many people are unaware that there are so many better selected forms. We do not grow the straight species for several reasons. They would generally be grown from seed, which naturally gives rise to variation. The plants can take a number of years to flower and then prove to be inferior. Imagine the disappointment!

By grafting, we can perpetuate a particular feature; whether that's flower size, growth habit and size, flower colour or foliage variegation. Over the years and around the world, many forms have been selected for these various attributes and named. Thus it is possible to plant something that you know will give the shape, size and overall effect that you want, as well as already being of flowering maturity. So much more satisfactory than leaving it to chance.

Cornus nuttallii as a species is rarely a happy plant in the somewhat damp British climate and prone to sudden death when grown from seed. By grafting it onto a more robust rootstock we can not only guarantee its floral and other  characteristics, but we can also make it easier to grow.

We graft all the selections of these flowering dogwoods onto Cornus kousa, getting the young plants off to the best possible start. It also ensures that the plants will flower from a very early age. 

In this manner, the plants are tolerant of a surprisingly wide range of conditions. As with so many plants, the ideal growing conditions would give adequate moisture when the plant is in leaf and actively growing, yet drain adequately well in winter when the plant is dormant and not able to use the extra water. The nuttalliis and floridas especially have large leaves which can lose water rapidly in the summer, so summer moisture is particularly important for them. However, they can be vulnerable to fungal problems in winter, so good air movement is valuable too. Interestingly, we have been told of plants doing well on chalk too. Cornus are naturally shallow rooting, so a good surface mulch in the spring can be very welcome in drier sites. As with all mulching, do be careful to ensure that it is not banked up against the base of the trunk. Many of this group of Cornus are late into leaf in the spring, typically not leafing up before before May. This can be useful in areas prone to late frost, but a little worrying if you're not expecting it! Do not be tempted to water them to "help" them into leaf, since this is the time when they are probably most vulnerable to over-watering. Similarly it's important to be aware that the foliage is often held in a manner where they seem to "hang" from the twigs. This is entirely natural, and does not mean that they are wilting. 

The species mentioned above are all deciduous, so loose their leaves in autumn. There are all also a number of evergreen and semi-evergreen hybrids and selections of flowering dogwood that hold their leaves long into the winter; a group that we have significantly expanded in our collection in recent years. 

Some of these are truly evergreen, whilst others are better thought of as semi-evergreen because they will eventually loose some or all of their leaves dependant on the severity of the weather. As a group, these will grow happily enough in even a very shady site, but often flower to their full potential with more light. Most evergreens can be more vulnerable to severe winter weather simply by virtue of having foliage at that stage. We are extremely exposed here, so we have first hand experience of how well they can tolerate frost and even high wind, the latter provided the ground is not frozen solid for any length of time. It is difficult to accurately classify many of these selections because of limited information regarding their origins.

All in all therefore, these really are fabulous plants for multi-season interest, with the variation in all features between the cultivars enabling the perfect plant to be selected for every occasion. Given that as a species Cornus kousa is the best suited of the group for the British climate, it is the one of which we have the most cultivars in the collection here. Indeed the range of options can seem daunting, so feel free to email me with a list of your requirements and I will recommend the best cultivar to suit you needs accordingly.

Below are some photos to illustrate some of the diversity and features of this wonderful group.