Kousa Dogwood is more upright, stiffly when young. With age it becomes rounded and spreading. Mosaic bark on older trunks – rich brown, tan, and gray – adds character, especially when wet or in winter. Similar to Flowering Dogwood, it grows 20 to 30 feet tall, though usually not broader.

A weeping Kousa cultivar, C. kousa Elizabeth Lustgarten, adds interest as a specimen planting. Its beautiful flower bracts line branches that arch out and downward. Given this habit, it generally stays smaller, growing only to 15 feet.

Dogwood hybrids

The greatest development comes from Rutgers University, where six hybrids were developed from Flowering Dogwood and Kousa Dogwood. They combine the best features of each – Flowering Dogwood’s stronger horizontal branching habit and the disease resistance of Kousa Dogwood. Like their parents, these hybrids will mature to 20 feet or slightly taller.

Rutger’s trees bloom earlier than the Kousa, midway between the bloom times for the parents. Because of hybridization, the flower is sterile and trees will not set fruit. This can be viewed as either desirable or a drawback. If you prefer not to attract birds, then the hybrids are for you.

Each hybrid offers variations on its parents’ blooms, some with pointed bracts, others with more rounded bracts. One outstanding variation comes with hybrid Stellar Pink (Cornus x Rutgan). It has Kousa’s pointed bracts, but with a distinctive soft pink color. Another, Constellation (Cornus x Rutcan), has beautifully full, rounded bracts similar to the Flowering Dogwood, in a soft white.

The formal names of these Rutgers Hybrids are similar and can get confused in the trade-as Rutgan and Rutcan mentioned above. Shop for trees when bracts are showing, if possible, to confirm that your tree blooms pink or white, as you wish.

Last but not least

There are two more 20-foot tree forms to consider. Their blooms lack showy bracts, but these trees abound with large clusters of flowers.

One is Cornus mas, or Corneliancherry Dogwood. Of all Cornus species, it is the most durable and longest-lived for Midwest use. It tolerates heavier clay soils, withstands sun or part shade, and has cold hardiness to Wisconsin’s zone 4.

It is an early-spring standout. More upright in habit, its multiple trunks extend into fine stems that bear myriad yellow flower clusters in March. The fruit ripen to a bright cherry-red in July. This fruit not only provides a snack for birds, it can be made into preserves or syrup-if you get there first. The cultivar, C. mas Golden Glory, is especially suited to the Chicago area.

Would I forget the Pagoda Dogwood? Not a chance! Cornus alternifolia is renowned for its strong horizontal branching with white flower clusters sitting atop glossy leaves in June. Whether single- or multi-stemmed, count on its layered branches to break up strong vertical architectural lines. It requires some shade to thrive, but has hardiness ratings to zone 3.

Don’t think of dogwood strictly as a shrub or a southern tree. Many types of dogwood trees will thrive in our area. Just give them some tender loving care and enjoy their beauty – without the drive south.

• Roberta Stewart is a horticulturist and woody plant specialist at The Planter’s Palette, 28W571 Roosevelt Road, Winfield, IL 60190. Call (630) 293-1040.

source : dailyherald.com

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