Magical Plants

Posted by & filed under Shrubs.

Hydrangea macrophylla 'Harlequin'Well the summer heat was turned on last week, so I decided to do my best magic trick by disappearing into the shade.  I’m not very good at magic, so I decided it is time to learn from the masters. I headed for the Hydrangea Garden.  Besides, it’s pretty shady there which always helps me to keep cool.

So who are these grand magicians?  Why the hydrangeas themselves.

What makes them so great?  First, like any good magician, the art of misdirection is a useful tool.  The average person walking into the hydrangea garden today will say to themselves, “What lovely flowers.”  Of course, are they really looking at flowers?  Yes and no. That is the art of deception.  When we see a big ball of little red or blue or white flowers, we are not looking at Hydrangea quercifolia 'Alice'one flower, but a corymb, which is a compound inflorescence (a grouping of flowers).  Hydrangeas have a variety of corymbs, but generally they fall into three groups – mopheads (the big round balls), lacecaps (a flatter flower) or panicles (cone-shaped ones).

The mopheads are some of the better magicians.  They make you think you are looking at flowers, but really they hide the true flowers deep inside the corymb.  The outer layer is made up of sterile florets and big showy sepals.  Sepals are the part of the plant that protects the actual flower.  Here they deceive you into thinking they are the flower.  

Hydrangea macrophylla 'Teller Pink'The lacecaps will show you the true flowers.  They are the small parts in the center and the larger sepals form a nice ring around the outer edge.  Before the true flowers open, the buds often look like a dish of pearls in the center of a colorful ring.  Since they show you the actual flowers, I think these magicians are more like Penn and Teller – they let you in on the secret but still dazzle and entertain you at the same time.

Panicles sometimes show their true flowers, but they are more like bad magicians, just trying to cover them up and not doing it well.

Hydrangea macrophylla 'Altona'Then of course, many of these hydrangeas are skilled at another trick.  They can change color.  How do they do that?  Come closer and I’ll share their secret.  
A little closer.
It’s aluminum.

Yes aluminum is the secret to hydrangea color.  If there is aluminum in the soil and available for the plant to take up, then the hydrangea will have blue flowers (or at least sepals).  Soil pH affects its ability to soak up the aluminum, so the more acidic the soil, the better it will be at this and the bluer it will get.  If the soil is too alkaline, or basic, then it will stay red.  Not all hydrangeas are affected the same way.  Some will usually stay red, some will stay blue and many white ones don’t care, but their true flowers may be affected.  Even flowers (and sepals) on the same plant may be different colors depending on how much aluminum it can soak up.  Now that’s a great trick.

So don’t let stories of Jack and his quick growing beans fool you.  The most magical plants in the Garden are hydrangeas and they are blooming right now.  Come see them during their limited engagement.  You won’t be disappointed – even if you know how the tricks are done.

Hydrangea macrophylla 'Le Cygne' Hydrangea macrophylla 'Bailmer'
Hydrangea macrophylla 'Kardinal' Hydrangea macrophylla 'Libelle'

One Response to “Magical Plants”

  1. Ann Onymous

    Don’t think much of panicles, do we? And if we apply Mitchum extra-strength anti-perspirant to the stem of the flower will it magically change color?