Hi Christina,

Thank you for contacting the UVM Master Garden helpline and providing your photos. The Kousa dogwood tree’s blossoms are gorgeous so it can be frustrating when it does not bloom. There are several factors that can affect the blooming:

- Inadequate soil moisture. Kousa dogwoods typically prefer well-drained, acidic (5.5 to 6.0 pH) moist soil that is high in organic matter. It has a shallow root system that benefits from a few inches of mulch and is more tolerant of dry conditions than the native flowering dogwood.

- Pruning. Improper pruning can remove the flower buds or disrupt the tree's growth pattern, affecting blooming. Dogwood trees only require periodic pruning to keep them healthy and should be done after they have finished blooming. Pruning dogwoods at other times can remove the immature buds and cause the dogwood tree not to flower.

- Nutrient deficiencies. Lack of essential nutrients, particularly phosphorus and potassium, can inhibit blooming. You may consider having a soil test to help determine if the soil lacks necessary nutrients. Soil test forms and instructions can be found on the UVM website: https://www.uvm.edu/extension/agricultural-and-environmental-testing-lab. Soil testing can also provide you with useful information regarding pH and organic matter content.

- Light requirements. It requires full sun to part shade. If your dogwood tree spends all day in shade, it may not be able to bloom correctly.

- Age. Young Kousa dogwood trees may take several years to reach maturity and bloom.

- Planting of the tree. From the photos, it is difficult to see the part of the trunk where the trunk flares out to become roots. If that is the case, the tree is planted too deeply. Additionally, avoid mulch directly against the trunk. For best results you should plant dogwoods at a level where the trunk flares out before it enters the soil. An illustration can be found on: https://tfsweb.tamu.edu/arborday/plantingsteps/

- Extreme temperatures. Plants placed where they are more susceptible to cold, such as in an open area and do not have protection from surrounding plants or buildings, will suffer limiting their ability to flower.

Additional information can be found on the following websites:

https://hgic.clemson.edu/factsheet/dogwood/

https://www.knoxcountymastergardener.org/resources/Documents/2021%20SB%20Handouts/Prune%20Like%20a%20Pro_Kousa%20Dogwood.pdf

https://www.uvm.edu/~pass/perry/oh40.html

https://www.oregonlive.com/hg/2023/05/my-big-beautiful-dogwood-is-hardly-blooming-this-year-what-gives-ask-extension-expert.html

I hope this information is helpful in order to determine the reason/s why your Kousa is not blossoming.