Plumbago - How to determine sunlight requirements | Green Patches - Mediterranean Gardening

Tuesday, October 4, 2011

Plumbago - How to determine sunlight requirements

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In this article I discuss how you can tell if a Plumbago is getting too much or too little sun.

Too much sun:

I have noticed that a plumbago can actually get too much sun.  If left in full direct sunlight at a temperature of around 95F to 100F (35C to 38C) which is what we get here in summer the flowers will turn yellow.  They will look bleached and wrinkly.  If the plant is not getting enough water the foliage will start getting yellow but still with sufficient water the flowers will lose their color.  If placed in partial shade but lots of filtered light the new flowers will resume their original color which in my case is lilac.  The flowers which have already bloomed will still be yellow so don't expect them to change color.

Too little sun:

If the plant is not getting enough direct sun or is in full shade all the time, the new blooms will be white.  They will also be smaller than normal, it seems like they were forced to bloom.  Even flowers which are covered in foliage and are not getting direct sunlight will turn out white.  Moving the plant to a sunnier place or a place which gets lots of filtered light should restore the color.

In my case my plumbago gets around 4 to 5 hours direct sun a day and for the rest of the day it gets lots of filtered light.  In the summer this is too much for it so I move it to a shadier spot but it still gets lots of light.  When I see that the new blooms are losing their color (this happens gradually in my case) I move it back out to a sunnier spot normally when the temperature start dropping.

Here's an illustration of flowers in the sun and flowers in full shade.  If the whole plant is getting paler or white flowers it's a good sign that it needs more sunlight.

This has nothing to do with watering needs which I always make sure are adequate.  Normally if the top two inches of soil are dry it's a good indication, then it's just a matter of increasing frequency in summer and reducing it in winter.

Plumbago Auriculata, Flowers
Plumbago in the sun

Plumbago Auriculata, Flowers
Plumbago in full shade

1 comment:

  1. We live about two hours west of Maroochydore in the hills in Qld. Our plumbago bushes flourish in sunny spots and we have one bush planted to the west of the house in full sun. They require very little water and generally rely on the rain. We only water them if we haven't had rain for a few weeks, as we only have tank water. I normally have a black thumb regarding plants but they are very hardy.