I am back at school taking the Advanced Master Gardener program at Van Dusen Gardens, and botany terminology are swirling around my head.
This is the third or fourth time since high school I've had the pleasure of learning how plants fit into the natural world and how they are classified, and even when you've heard it before - it never fails to open your eyes.
For me, the science of horticulture is especially key for gardeners, and whatever level we chose to understand is fascinating. I work with plants all the time, but often disregard the bones of plant structure - remember cells and mitosis? And the hows and whys of what plants do?
A client asked me the other day for a suggestion of a tree with wonderful fall foliage. When designing for a residential lot, it's important to remember to plan for fall like you would spring and summer blooming plants.
Everyone enjoys the colours of fall foliage, but do you ever wonder how the leaves of a Maple turn red, or where yellow and orange leaves come from?
As fall progresses and temperatures get cooler, trees stop producing chlorophyll (the molecule that is responsible for keeping leaves green).
Levels of chlorophyll drop off and yellow and orange carotenoid pigments in leaves are revealed. Small amounts of these colours have been in the leaves through summer but they are covered up by the green chlorophyll and we don't see them until fall.
Some great suggestions of small trees with brilliant yellow fall foliage are Sango Kaku, the Japanese coral bark maple, Ginko biloba or Princeton Sentry, Acer shirasawanum or Aureum, the full moon maple, and one of my favourites - Cercidiphyllum japonicum or Morika Weeping.
Reds and purples that are found in leaves are made mostly in the fall too. In a tree like a maple (Acer), sugar is trapped in the leaves after photosynthesis stops. Sunlight and cool nights turn the sugar into a red colour.
Some deciduous trees with beautiful red foliage include: Acer circinatum (the vine maple) - which you should try and buy when in fall colour as not all of them are red.
Cornus Kousa, the oriental dogwood, Oxydendrum arboretum - also known as the Sourwood tree, Crataegus phaenopyrum (Washington hawthorn) and the Liquidambar styraciflua (Sweet gum).
Step into fall.
