Red Foliage and What it Means

dwarf heavenly bamboo (Nandina domestica ‘Compacta’)

Red Foliage Unites Spring and Fall

If there is one phenomenon that unites spring and fall in the garden, other than mild temperatures and planting sprees, it would have to be a certain leaf color.  In both seasons, red foliage greets the eye.  In spring, new leaf and shoot growth on many plants emerges in scarlet to burgundy red, while in fall, the leaves of deciduous trees, as well as the foliage of certain evergreen shrubs such as heavenly bamboo (Nandina species), are also steeped in red.
Red Foliage is an Asset for Plants
Just as people may blush or become facially flushed in red in vulnerable moments, so too with plants.  Moreover, at least where plants are concerned in early spring, when frost is still an ever lurking danger to tender, young leaves, redness becomes an asset.  Leaves need to be as robust as possible to withstand a frost, and since new leaves are particularly susceptible to cold damage, they cannot afford to be in a weakened condition.  Studies have shown that green foliage is more susceptible to insect and disease depredations than red foliage.  Red foliage is less attractive to pests and less susceptible to disease so it will be in good overall health and thus more capable of withstanding a frost than if it were green.
Pests Less Inclined to Visit Red Foliage
One hypothesis as to why pests are less inclined to visit red than green leaves rests on the fact that insects have little interest in senescent or aging leaves.  As leaves get older in the fall, they begin to turn red or at least have some hints of red, the same color as new spring growth.  Thus, insects are fooled into thinking the new leaves are really like the old and stay away from them.
There are exceptions to this rule, such as the appearance of aphids on fresh, reddish burgundy growth of roses and the magnetic attraction exerted on insects by the bright red leaves of a carnivorous, insect devouring sundew plant (Drosera spathulata)  from New Zealand.  Relatively little research has been done on anthocyanins, the pigments that make leaves red, insofar as pest deterrence is concerned and why red leaves on certain species, as opposed to the vast majority of them, are still pest susceptible.
Photinia has Brightest Red Foliage
Speaking of red leaves, the species with the brightest red spring foliage, by far, is red tipped Photinia (Photinia x fraseri).  Not long ago, this plant was everywhere.  You would keep pruning the incipient red shoots and leaves in order to stimulate ever more new, red growtj since, as summer arrived, all foliage, new and old, would settle into being green.  Alas, this plant has been so devastated by photinia leaf spot, a fungus disease, that it has become a rarity.  But botanical plagues come and go and there is ample reason to believe that, in the not too distant future, red tipped photinia will once again grace our spring gardens.
Young Red Foliage in Spring
This spring, I have noticed pest free red to burgundy growth on lemon, eucalyptus, pomegranate,and carob trees.  There is something about this blood colored growth that always brings a smile to my face, and perhaps to yours as well. It might be the contrast, the uncanny defiance of green in the young foliage.  It could even be a reminder of our own rebellious youth, which still refuses to completely acquiesce to the more acceptable and predictable  green (the color of money?) that takes hold of our lives as we grow older.  This fresh red growth is an annual reminder that there is still blood in our veins and that our true calling is to live passionately and without compromise.
Sites (rites?) of spring involve an assessment of which tree shows off more brilliant pink flowers, peach (Prunus persica) or love tree (Cercis siliquastrum).  Both are blindingly pink and those of you who demand that plants flower over a long period of time will change your tune once you gaze upon either one of them in full flower. But let’s assume that you have no more room in your garden to plant trees, however epiphanical their blooming may be, yet nonetheless have a craving for pink.  Let me suggest Canterbury bells instead.  Canterbury is a suburb of London and, yes, if you ever happen to visit there you will see Canterbury bells (Campanula medium) wherever you go.  You may see it in blue, in purple, in white, or in pink.  But no matter which color you see, you will quickly admit that larger bellflowers you are highly unlikely to encounter, at least not in this lifetime.
Tip of the Week:  Senecio vitalis is not a species from which a hair product is made.  For you youngsters, Vitalis was a heavily advertised hair product in the 1960‘s.  I  remember regularly slicking it on my own hair before bounding off to my sixth grade morning class.  Senecio vitalis is an eminently suitable succulent mainstay for covering ground in a drought tolerant garden.  Not long ago, off Riverside Drive in Sherman Oaks, I saw a minimalist garden that consisted of nothing but Senecio vitalis specimens.  This is a clumping species that, in time, may completely cover your front yard.  Hats off to Sencio vitalis, even if it is without benefit to the hair exposed , in opposition to its species name, once hats come off.  By the way, for those of you who wish to relive your youth, Vitalis hair oil remains available through online vendors.

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