The flowers of Cercis appear in the early spring before the leaves unfurl and the pea shaped flowers are a very beautiful sight. There are many cultivars available with flowers of white, pastel pink right through to very dark pink—almost red. However there is a great variation in the amount of flower and this is dependant on several factors.
Firstly some species are much more prolific than others. The chinensis varieties are the most floriferous, with the texensis coming in second place.
Secondly there is variation in varieties within species so in canadensis the Forest Pansy which is so treasured for its wonderful red leaves, actually has very few flowers. (the new Merlot is much better in this character)
Thirdly the age of the plant is important. Cercis is the only temperate tree to have the character called “cauliflory” which is the ability for a plant to flower on its main stems and woody branches rather than the new growth and shoots and so the potential number of flowering nodes increases with age as the plant becomes larger and the wood more mature.
Finally the location of the Cercis is important. In cooler climates like the UK, flowering is somewhat less than in southern Europe or the USA where the very hot summers cause the wood to become mature and more likely to produce full canopies of flowers the following spring. However in the southern half of the UK good flowering is still achieved particularly with the chinensis varieties, while the red leaf colour especially of the Ruby Falls and Merlot is far more pronounced in our climate with the cooler nights. These usually also give better autumn leaf colour displays in our climate. To maximise flowering in the UK place the tree in a warm location, even full sun is ok, and use one of the better flowering varieties. It will do well and bring enjoyment for many years. If you live in one of the cooler areas as we do then relax and appreciate the wonderful leaf colour and appearance of the Ruby Falls or Merlot.