The Season of White

With what seems to be an endless array of Hydrangea paniculata cultivars entering the market, July has turned the garden into a snow white scene. The Asian Hydrangea paniculata was first published as a new species in 1829, but was not grown in the Americas until Arnold Arboretum director, Charles Sargent brought back seed from an 1892 expedition to Japan. That original plant, now, 131 years old, measures 16′ tall x 25′ wide. I’m not saying you need to plan for your Hydrangea paniculata to reach 131 years old, but the average of a house in the US is 46 years, so logic says we should at least plant for a 50 year mature size.

Below is our clump of Hydrangea ‘Rensun’, which is marketed under a completely different name, Strawberry Sundae. The introducers of this lovely clone tout this as maturing at 5′ tall x 4′ wide, but our 6 year old specimen is already 7′ tall x 11′ wide. Based on that growth rate and the mature size of the species, I’d expect it to reach 14′ wide x 22′ wide in 50 years. It’s truly fascinating why it’s so difficult to for plant breeders to get more accurate measurements before these plants are introduced to market. One can only imagine the maintenance problems caused when you locate plants based on the size given on the plant tag, only to have the plant get 2-4 times as large as your space allows.

Hydrangea paniculata ‘Rensun’

A Taste of Honey

Looking stunning now is one of our favorite native shrubs, the golden leaf selection of Hydrangea quercifolia, named ‘Little Honey’. Our plant below is now 19 years old, and measures 4′ tall x 7′ wide. There are few woodland plants that can brighten a corner the way this gem can–and this is without the spikes of white flowers. Hardiness is Zone 5a-9a.

Slightly Deranged Hydrangeas

We love the genus Hydrangea, but are really fascinated by those at the far end of the family tree. While most hydrangeas flower in late spring, we actually have a couple flowering now we’d like to share.

The first is Hydrangea involucrata, a native to both Japan and Taiwan. The word “involucrata” indicates it has some serious involucres (the bracts surrounding the inflorescence). The first image shows the plant in bud, the second in full flower, and the third image is after the flower color has faded. All three stages are on display at once in the garden this week. They typically reach 6′ in height and width. Winter hardiness is Zone 6a-8b.

Hydrangea involucrata in bud
Hydrangea involucrata in bud
Hydrangea involucrata flowering
Hydrangea involucrata

Hydrangeas flowering
Hydrangea involucrata

Hydrangea amamiohshimensis (below), from Japan’s southern Ryuku Islands, was once considered a hydrangea cousin, until a 23andMe test confirmed it was actually a true hydrangea. Prior to the test, it belonged to the genus Cardiandra, which was effectively a perennial hydrangea, dying back to the ground each fall like most perennials. It too is in full flower in the woodland garden this week. Perhaps now that it has a recognizable name, more folks will be willing to grow it. This is the only one of the four former cardiandra species that has survived in our climate.

Hydrangea amamiohshimensis

Summer Textured Ferners

Here’s a fun textural image from the woodland garden, featuring Hydrangea quercifolia ‘Little Honey’, Farfugium japonicum ‘Aureomaculatum’, and Athyrium ‘Ocean’s Fury’. Off to the left side are three more ferns, Dryopteris x celsa, Adiantum capillus-veneris, and Ctenitis subglandulosa.

Hydrangea quercifolia 'Little Honey', Farfugium japonicum 'Aureomaculatum', and Athyrium 'Ocean's Fury' and ferns - Dryopteris x celsa, Adiantum capillus-veneris, and Ctenitis subglandulosa
Hydrangea quercifolia ‘Little Honey’, Farfugium japonicum ‘Aureomaculatum’, and Athyrium ‘Ocean’s Fury’

Bobo and Bro

Here’s a fun combination from the gardens today with Hydrangea paniculata ‘Bobo’ underplanted with Sedum ellacombianum ‘Cutting Edge’, which nicely echos the various shades of green in the flowers.

Immaculate Maculata

Even with all of the amazing new Hydrangea macrophylla introductions, it’s hard to beat the old Japanese cultivar, Hydrangea macrophylla ‘Maculata’. Hope you enjoy this shot from JLBG this week.

Keeping up the Spirit

In 2009, we first planted the Tom Ranney (NC State) introduction of Hydrangea ‘Spirit’..his creation of a pink-flowered selection of the usually white-flowered NC native Hydrangea arborescens. Here it is today, twelve years later and still looking superb in the gardens at JLBG. Over $1 million dollars from the sale of this plant has been donated to breast cancer research. What a lovely plant and lovely story!

Friday Morning Podcast

Here are some interesting fruits and seed pods from the garden this week.

Many Hydrangea have colorful sepals that persist long after the plant has flowered, extending it’s season of interest.