Hydrangea macrophylla ‘Twist-n-Shout is a lacecap variety. Lacecaps are some of the true aristocrats of the hydrangea world, graceful yet not as overwrought as some other cultivars. Hybridized by Michael Dirr from the University of Georgia, ‘Twist-n-Shout’ Hydrangea reblooms throughout the growing season. Part of the Endless Summer series, ‘Twist-n-Shout’ flowers on both new and old wood.

‘Twist-n-Shout’ is a fine hydrangea and you can have it in pink or blue simply by changing the pH of the soil. It was patented in 2007, and as I recall, made it into commerce around 2011. Before it was ‘Twist-n-Shout’ it was PIHM-1.

I don’t know if I trust plant descriptions from online retailers, as they repeatedly demonstrate a willingness to alter flower colors and stretch acceptable growing conditions in order to sell more plants. I do trust Michael Dirr, however, and the patent is interesting reading. The thing that jumps out is the resistance to powdery mildew, which is described by Dirr as excellent.

Hydrangea ‘Twist-n-Shout’ has beautiful red stems and flowers that are somehow hot and soft at the same time.

Dirr indicates ‘Twist-n-Shout’ hydrangeas are hardy zones 5-9. You will see most online retailers indicate hardiness to zone 4. I live in zone 8a, so I can’t say either way. I’d suggest giving ‘Twist-n-Shout’ a try even in colder zones and see what happens.

It was hybridized from ‘Penny Mac’ and ‘Lady in Red’. Penny Mac is a macrophylla that blooms through summer and produces flowers on both old and new wood. Penny mac can produce both lacecap and mophead flowers. ‘Lady in Red’ is a deep pink lacecap hydrangea that has smaller flowers than ‘Twist-n-Shout’. ‘Lady in Red’ has red stems and unlike ‘Twist-n-Shout’ blooms only on old wood.

Dirr’s hybridization efforts were successful in that he was able to selectively breed for the best qualities of both Penny Mac and ‘Lady in Red’. ‘Twist-n-Shout’ has larger flowers, remontant flowering, and those beautiful red stems.

Penny Mac is hardy to zone 5 and ‘Lady in Red’ to zone 6. So I circle back to the hardiness zone recommendations offered by many retailers and wonder how did they settle on zone 4 when even the patent did not indicate such cold hardiness? It’s a potentially important point because there are indications the plants may survive winter in cold climates but the flower buds may not.

Still, plants are adaptable and I suppose microclimates could create successful conditions for growing ‘Twist-n-Shout’ in colder areas.

Growing ‘Twist-n-Shout’ Hydrangeas

Hydrangeas are easy to grow if you have the discipline not to stray outside their comfort zones. Hydrangea macrophyllas uniformly prefer afternoon shade. It is a must. Morning sun with afternoon shade is perfect. You could also grow them in areas with filtered light. If you are looking for varieties that can handle afternoon or full sun, then any of the Hydrangea paniculata cultivars will do. ‘Limlelight’ is still the best.

Plant in good quality rich and loamy soil. Add plenty of decayed matter or compost into the planting hole. Adding a slow release fertilizer as the plants begin growth in spring is a good idea, although we normally just add one or two inches of compost every year.

By the way, hydrangeas, and not just ‘Twist-n-Shout’, make great container plants.

Pruning ‘Twist-n-Shout’ Hydrangeas

Regarding pruning, the terms new wood and old wood are normally specified for woody plants. New wood means plants bloom on the current year’s growth. Old wood means plants bloom on last year’s growth. The implications are crucial. Plants described as blooming on new wood can be pruned anytime without risking the current season’s flowers. However, if you winter prune oakleaf hydrangeas, which bloom on old wood, you are cutting off the current season’s buds.

I have a number of oakleaf hydrangeas in my garden that will not bloom this year because I unexpectedly had to prune them this past winter. It happens and is not the end of the world.

‘Twist-n-Shout’ blooms on both new and old wood. This means you can, in theory, prune any time you want and still get some bloom from the current season’s growth. Still, a good rule of thumb is to prune Hydrangea macrophyllas when the shrub is actively growing. The later in the season you wait, the more chance it will not have time to put on new growth for old-wood flowers the following spring.

Changing the Flower Color of Hydrangeas

Hydrangea macrophyllas are not choosy about pH, but it will affect the flower color. By the way, the flower color of white hydrangeas is not affected by pH. I am often written with the question of how to turn oakleaf hydrangeas or Annabelle hydrangeas pink or blue. It doesn’t work that way with the white hydrangeas.

With regards to ‘Twist-n-Shout’ Hydrangeas, you can affect flower color. Soils with acidic pH will yield plants with purple-blue flowers and alkaline soils will produce pink flowers. Lime can be added to move the pH to alkaline. If you need more acidic soil, incorporating a compost or soil mix intended for azaleas and rhododendrons will do the trick.

Michael Dirr

Michael Dirr has had a long and illustrious career. My favorite thing he did was introducing Calycanthus floridus ‘Athens’, a beautiful, soft yellow sweetshrub. Dirr is famous for a lot of things. Perhaps his crowning achievement is the Manual of Woody Landscape Plants: Their Identification, Ornamental Characteristics, Culture, Propagation, and Uses. 

Even with the unabridged title typical of academics, the book is a classic. I carried a copy everywhere I went as a student, and that was two decades ago. Now in its 5th edition, the book is over 1100 pages of insightful and accurate descriptions of hundreds of shrubs and trees.