Sun Leaves Vs. Shade Leaves

Yes they can. Any leaf will adapt to the light conditions it receives however it must be a gradual process.

To give an analogy, think about building muscle. If you go and try to life 400 lbs having never trained, the weight will crush you. If you progressively work up to that weight over the course of days, months and years - eventually you may be strong enough to carry the load.

Same goes for tree leaves. This is why if you move a tree (or any plant) from one location to another, you need to pay attention to the environment.

For example, moving a plant from indoors to outdoors in the full sun would be disastrous. Uprooting a tree from a mostly shaded area to direct sunlight would also prove disastrous.

Shaded leaves have a larger surface areas whereas sun leaves tend to have smaller surface areas because shade leaves aren't exposed to as much sunlight. Being exposed to rather low light intensities, the leaves grow and expand in an attempt to capture as much sunlight as possible.

To give an extreme example (and even though we are talking about trees), think about Hostas. Hostas are a shade loving plant (one of our favorites) and they have evolved to have large surface area, deep green leaves.

Keep in mind, shade leaves are certainly bigger than sun leaves but the leaf thickness of the sun leave can be up to 50% more than the its shaded counterpart.

Sun leaves have extra layers of palisade mesophyll cells. As they are exposed to higher levels of light, the leaves require additional amounts of chloroplasts to capture and covert that light energy for the tree.

So although the leaves are smaller in size, they have a higher amount of photosynthetic capacity.

Shade leaves get much less sun than a sun leaves. As a result, the chloroplasts are larger. Larger chloroplasts contain more chlorophyll. Chlorophyll gives the plant its green color - among other things.

Sun leaves are lighter green simply because they don't need as large chloroplasts to capture light energy.

The palisade layer of the cell is where photosynthesis occurs in the leaf. Palisade mesophyll cells hold the chloroplasts which, if you remember from biology class, are the plant cell organelles that convert light into energy for the plant.

Great question. And the science isn't totally clear.

Sun leaves no doubt have adapted more to sun than shade leaves but like everything thing in nature, they can only adapt to their genetic limits which in this case refers to how quickly they can adapt.

Perhaps you've moved a plant from your house directly into the sunlight and noticed it quickly burnt. The theory being that the plant leaves were exposed to higher levels of radiation too quickly and temperature of the leaves became so hot that the photosynthetic cells were damaged resulting in photo-inhibition.

Another potential cause is excess levels of sun for the tree species combined with low level of moisture in the soil. Some species are much more sensitive to drought, and it can have an effect on the appearance of the leaves. If the injury isn't too bad, the tree should be able to heal itself.

Absolutely. There will always be a variety of adaptations among different species of tree for sun, and a variety of other factors.

Some examples of shade loving trees are Japanese maples, the American beech, and the Pagoda Dogwood.

Some examples of sun loving trees are the Grand Fir, Mountain Hemlock or the Snowbrush.

We are always hesitant to give blanket example lists like this because there are so many variables depending on your location. Not only that, but trees that love the sun or love the shade should not necessarily be planted in these extremes (sun only vs shade only type of thing).

Remember the leaves adapt and trees exist on a spectrum.

Tree leaves aren't hard to trim. That all depends on the branch.