Plants of the Week: July 1

It’s unofficially hydrangea week here at The Scott Arboretum of Swarthmore College. Most of them are currently in bloom and will persist all summer long. There are 346 individual hydrangea plants located throughout the arboretum. I feature 4 of my favorites below. Enjoy…

Hydrangea macrophylla ‘Lynn’ is sure to be an eye-catcher in any garden. Let’s Dance^TM Starlight big-leaf hydrangea is part of the new Let’s Dance^TM series which are the first ever reblooming lacecap hydrangeas. They flower on both old wood and new growth. Their colorful blooms are not the typical mophead variety, they are the unusual lacecap type which used to be rare to our region. This hydrangea’s flower heads consist of small closed flowers in the center surrounded by an outside ring of big showy florets circling them that change color based on soil acidity levels. Acidic soils cause blue flowers while basic soils result in pink flowers with a range of colors in between this spectrum, even on the same plant. The “hydra” part of its name signifies that it loves water, however good soil drainage is very important.

Photo Credit: Aaron D’Addio

Garden Location: Terry Shane Teaching Garden

While Schizophragma hydrangeoides ‘Moonlight’ is not truly a hydrangea, it is still in the hydrangea family: Hydrangeaceae. ‘Moonlight’ Japanese hydrangea vine is a deciduous, woody-stemmed, self-clinging vine that will easily climb walls and accent beautiful architecture such as the stone arches of Clothier Hall. It is known for its large, fragrant, cream-colored, lace cap flower clusters which closely resemble those of lace cap hydrangeas and can bloom for up to 2 months. Their foliage is heart-shaped, blue-green with green veins, and a silver cast until turning a pleasant yellow in autumn.

Photo Credit: Aaron D’Addio

Garden Location: Clothier Hall

Hydrangea quercifolia ‘Snow Queen’ is native to the southeastern U. S., making it one of the few hydrangeas native to the United States. ‘Snow Queen’ oakleaf hydrangea is noted for its unique, deeply lobed foliage closely mimicking that of oak leaves, hence its specific epithet. Another well-known characteristic of this plant, besides its leaf texture, is its large, dense, 6 to 8 inch long conical clusters of creamy white upright flowers which later transform into a pinkish-purple color with burgundy fall foliage. It flowers on the previous year’s growth. This plant also features cinnamon colored exfoliating bark, thus adding attractive winter interest.

Photo Credit: Aaron D’Addio

Garden Location: Terry Shane Teaching Garden & Hydrangea Collection

Hydrangea arborescens Incrediball^TM produces massive flowers that can be the size of a basketball! Incrediball^TM smooth hydrangea is a new selection from its native parent ‘Annabelle’ with four times as many flowers, and is undoubtedly the largest-flowered mophead hydrangea in the world! These huge blooms are on very sturdy stems, flower all summer long, and open lime-green at first, maturing into pure white, then returning back to lime-green again. This plant is very hardy and perfect for bouquets and fresh or dried floral arrangements. Cut back in spring to promote flowering on new summer wood.

Photo Credit: Aaron D’Addio

Garden Location: Terry Shane Teaching Garden