Sunny Boulevard St. John's Wort

Sunny Boulevard® St. John’s-wort is the trade name for the named cultivar ‘Deppe’, a compact, rounded deciduous shrub with narrow green leaves and bright yellow flowers. It typically grows 2–3 feet tall, while published width estimates range from 2–3 to 3–4 feet, so allow 2–4 feet for its natural mound. ## Selection and bloom NC State describes ‘Deppe’ as an open-pollinated selection of *H. kalmianum* developed in a controlled breeding program in 2002. In UC Davis’s landscape trial, plants in Davis flowered from June through July and attracted pollinators. U.S. Plant Patent PP20,045 was issued June 2, 2009. [NC State Extension](https://plants.ces.ncsu.edu/plants/hypericum-kalmianum-sunny-boulevard-deppe/), [UC Davis Landscape Plant Irrigation Trials](https://uclpit.ucdavis.edu/hypericum_Deppe), and the [U.S. patent record](https://patents.google.com/patent/USPP20045P2/en) document this named selection. ## Siting Give it full sun for its best growth and flowering, in well-drained soil. Proven Winners lists average-to-low water needs and says it is very drought tolerant after establishment; water while young and avoid persistently saturated ground. NC State lists the cultivar for clay, loam, and sandy soils, and describes tolerance of occasionally dry and wet conditions. UC Davis observed poor performance under reclaimed irrigation water at its Irvine trial but good appearance across irrigation treatments at Davis, so local water quality matters. Sunny Boulevard suits a sunny border, edging, low hedge, or mass planting. [Proven Winners ColorChoice](https://www.provenwinnerscolorchoice.com/product/sunny-boulevard-st-johns-wort/), [NC State Extension](https://plants.ces.ncsu.edu/plants/hypericum-kalmianum-sunny-boulevard-deppe/), and [UC Davis](https://uclpit.ucdavis.edu/hypericum_Deppe) provide the selection and care details. ## Maintenance This naturally neat mound needs little routine pruning. If shaping is needed, NC State recommends pruning after flowering; the UC Davis trial also evaluated an early-spring cutback to 6–8 inches before growth. Keep it out of livestock forage: NC State notes that *Hypericum* species can cause photosensitivity and digestive irritation in farm animals. [NC State Extension](https://plants.ces.ncsu.edu/plants/hypericum-kalmianum-sunny-boulevard-deppe/) and [UC Davis Landscape Plant Irrigation Trials](https://uclpit.ucdavis.edu/hypericum_Deppe).