November 2011 Newsletter©

Plants Are Smart!

Yes, these are Christmas cactus…in bloom…at Halloween.  Want to know why?  Well I’m going to tell you anyway! Many plants are stimulated into bloom by the length of the night.  Dianthus starts blooming as the nights get shorter in the spring.  Mums, poinsettias and Christmas cactus start blooming as the nights get longer in the fall. When the uninterrupted “photoperiod” gets just the right length, flower bud formation is stimulated and you get flowers.  Some plants are so sensitive to this period of darkness that turning on a light even briefly can disrupt the bloom cycle.  Streetlights, porch lights and gas lanterns often give off enough light to interfere with flowering. 

Until fairly recently, poinsettias had to be shaded for 12 hours by growers to get them in bloom at Christmas.  If you didn’t shade them, they would not bloom at Christmas and they are really hard to sell at any other time.  Homeowners who kept last years poinsettia had to put them in closets for 12 hours and even light coming under the door could disrupt the bloom. Now however, many poinsettias have been bred to come into bloom at the correct time without shading.  Which brings us back to my Christmas cactus, why are they early?

Under normal conditions, they would bloom at Christmas.  There are other varieties that normally bloom at Thanksgiving, but if you start shading them at just the right time, you can make them bloom whenever you want.  These have been in a western facing kitchen window with mini blinds for about 10 years.  There are tall trees just to the south and the amount of dark was just right for them to bloom at Christmas.  This year, I decided to move them outside on the deck.  Same side of the house but they were against a western wall under a 6’ overhang.  The overhang kept the sun away until later in the day, so they sensed a longer night which stimulated blooms…two months early. 

Plant the same variety of mum on the east and west sides of your house and they will bloom at different times. Lots of cloudy weather in April and May will delay the flowering of crape myrtles.  Most plants are “day-neutral”, they will bloom regardless of the photoperiod length. “Long-day” plants are those that bloom as the days get longer in the spring. “Short-day” plants are those that bloom as the days get shorter in the fall.  But it is not the light that regulates the bloom, it is the dark.  The light sensitive proteins that control flower production in the plants above, also stimulate root production in some plants and fall leaf drop in others.

Light, or rather lack of it, controls growth also.  Have you ever seen a plant next to a window “grow” towards the light or a plant next to a wall lean away for more light?  Correctly, they are “growing” away from the light.  The hormones that regulate cell wall length accumulate on the “dark side” of the plant.  This causes the cells on the “dark side” to “grow” or elongate which turns the plant towards the light.  This does two things for the plant. It turns the upper leaf surface towards the light so it can absorb more light to produce food and it also serves as a self-defense mechanism by allowing the foliage to shade and protect the stem from the sun.

On the surface of a leaf there is a waxy layer called the cuticle.  Light regulates the thickness of the layer and it has several functions.  It helps protect the plant from some insects and pathogens, regulate water loss and it helps protect the cells from sunlight.  Leaves on the outside of a branch in full sun have thicker cuticle layers than leaves on the inside of the plant.  That is why it is never a good idea to trim the top out of a tree when it has foliage.  The internal leaves, now exposed to full sun, will cook.  If you move a tropical plant from a bright light location to a lower light location, often the next few new leaves will be contorted as the plant adjusts the cuticle layer thickness to its new lower light situation.

So plants are smart enough to sense changes in day (or night) length and the direction and intensity of the light, but did you know that they can also talk to each other?

When some plants are attacked by an insect or disease, the chemistry of the plant changes.  Hormones are released that thicken the cell walls in self defense and in some cases toxins are formed to deter the attacker.  This change happens very rapidly and some of the hormones are released through transpiration into the air and are sensed by like, nearby plants.  The chemistry changes in the nearby plants also, even though they have not yet been attacked.  They were just warned by a neighbor…as much as a mile away!

Now let’s take a look a few camellias in bloom right now…

From the left…

Setsugekka (Camellia sasanqua) - This variety has large, white, semi-double flowers, petals are slightly ruffled. Upright habit with some slight weeping appearance to 12’ tall and nearly as wide.  Starts blooming in October and it often has flowers into late January or early February.  Hardy in USDA Zones 7-8.

Bonanza (Camellia sasanqua) – Semi-double to peony form scarlet red flowers.  Spreading habit to 5’ tall and 6’ – 8’ wide.

Two Martha’s – This is a USDA introduction, one of the Ackerman hybrids that are very cold hardy.  Semi-double rose pink flowers, upright open habit to 15’ tall and 10’ wide.

Winter’s Charm – Another Ackerman hybrid from the USDA with light pink, semi-double to peony form flowers.  Grows to 7’ tall and about 4’ wide.

From the left…

Shi Shi Gashira (Camellia hiemalis) – One of my favorites, this is a dwarf, compact, spreading cultivar to 4’ tall and up to 8’ wide, but 5’ – 6’ is more common.  Reddish/pink flowers vary from semi-double, to rose-double to peony form and bloom for a very long period. I’ve had them with blooms from late September until early January.

Chansonette (Camellia hiemalis) - This is another dwarf cultivar that grows to 4’ tall and 6’ wide.  Habit is somewhat open and pendulous.  Flower is a rose pink formal double.

Winter’s Star – Another USDA Ackerman hybrid with single light pink flowers.  Grows to about 6’ tall and wide.

Apple Blossom (Camellia sasanqua) – A very attractive two-toned flower.  Petals are white and edged in light pink.  This one grows to 10’ tall and wide.

We have over 40 varieties of spring or fall blooming camellias in stock right now, so come by and take a look!

Here is the picture that won the September contest.  Good looking coneflowers. I’ll show you the October winner next month.

I had a customer in this week that said she did not enter this contest because she did not know many plant names.  We occasionally have an equal opportunity contest like when the question was “How many stores does Dan West have?”  (We had some people miss that!)  This is another one of those contests.

These are two wonderful oaks.  One is a nuttall oak (Quercus nuttallii) and the other is a pin oak (Quercus palustris).  Both have exceptional fall red color.

The contest is…which is which?  You may enter twice per email.  All correct answers will go in a hat and one will be randomly chosen to win.

Warning: I will reveal the name of anyone that guesses twice and misses them both!

The contest ends on November 30th.  Email your entry to questions@danwestonline.com.  One winner will receive a $25 Dan West Gift Certificate.

Thanks for shopping with us at Dan West.