Pink Kousa Dogwood not so pink - Ask Extension
I planted a Cosey Teacup Kousa Dogwood in 2020. For the first few years the Dogwood flowers were a deep shade of pink. This year the flowers are hard...
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Pink Kousa Dogwood not so pink #868015
Asked May 11, 2024, 3:10 PM EDT
I planted a Cosey Teacup Kousa Dogwood in 2020. For the first few years the Dogwood flowers were a deep shade of pink. This year the flowers are hardly pink and the whole tree resembles an ordinary Kousa. The tree was originally planted in an area where there was a large ornamental Cherry tree. The remaining roots are throughout the front lawn and around the Cosey Teacup. I don't know if that makes a difference. I haven't tested the soil - what is the optimum ph for a Pink Kousa. Also we want to prune the tree to keep it small so we don't overwhelm the small front yard. When would be the proper time to prune it.
The 1st pic was in 2020, the second taken today. Although different perspectives, the flowers in the 2nd pic has hardly any pink compared the the 1st pic.
Thank You
Montgomery County Maryland
Expert Response
The leftover cherry roots are likely inconsequential, though they are degrading into nutrients the tree will be able to use later, as its roots infiltrate that area. Although we don't have research determining how pervasive the issue is, in our experience, pink-flowered dogwoods of all types (kousa, florida, etc.) can be paler in color in springs with warmer weather, and richer pink in cooler conditions. Plant genetics certainly plays a role in flower color richness, but the rest of the impact likely comes from environmental conditions like ambient temperature. The Rosy Teacups cultivar is a hybrid between Kousa Dogwood (Cornus kousa) and Pacific Dogwood (Cornus nuttallii). Its west coast parent likely prefers cooler conditions than we get here, since it is native in the Pacific Northwest as well as the mountains of California. If that is true, then the color of the blooms might be at the mercy of the weather any given spring.
According to Rutgers University, the mature size listed for this variety is in the range of about 20-25 feet high and wide, typical for a non-dwarf kousa-type dogwood. It would be best to let the tree get as close to its mature size as possible, as regular pruning creates wounds that might risk getting colonized by borers or wood decay, either of which can be treated. There are a few dwarf dogwood cultivars that would not need pruning to restrain size, though options for flower color may be more limited in that case. Virginia Tech advises that dogwoods should not be pruned outside of a narrow window of time in the June-July period, mainly to avoid interrupting flowering. (If you didn't mind losing some flowers for a year, you could probably prune in late winter as well, since that will remove some of that spring's blooms.)
Kousa Dogwood is not as picky to soil pH as our native dogwood is, though slightly acidic soils are still preferred. That said, Kousa Dogwood can also grow well in near-neutral soil (around pH 7.0) without any intervention, so if the lawn has been limed in the past few years to raise pH, that's probably not an issue.
Miri
According to Rutgers University, the mature size listed for this variety is in the range of about 20-25 feet high and wide, typical for a non-dwarf kousa-type dogwood. It would be best to let the tree get as close to its mature size as possible, as regular pruning creates wounds that might risk getting colonized by borers or wood decay, either of which can be treated. There are a few dwarf dogwood cultivars that would not need pruning to restrain size, though options for flower color may be more limited in that case. Virginia Tech advises that dogwoods should not be pruned outside of a narrow window of time in the June-July period, mainly to avoid interrupting flowering. (If you didn't mind losing some flowers for a year, you could probably prune in late winter as well, since that will remove some of that spring's blooms.)
Kousa Dogwood is not as picky to soil pH as our native dogwood is, though slightly acidic soils are still preferred. That said, Kousa Dogwood can also grow well in near-neutral soil (around pH 7.0) without any intervention, so if the lawn has been limed in the past few years to raise pH, that's probably not an issue.
Miri
