Monthly Archives: October 2012

An Autumn Walk Through Sam Lewis State Park

After work I dropped by Sam Lewis State Park and took a few pictures of the fall colors. The day was warm and a little hazy so I wasn’t able to take many panoramic shots. Also the colors of the first picture might seem a little extreme – using the vivid setting on the camera was the only way to see the wind turbines through the haze! All the other picture show the “natural” color of the day.

Turkey Hill Wind Turbines in Lancaster County across the Susquehanna

York County

Looking Up I

Looking Up II

Looking Up III

Sunlight Through a Tree

Lichens and Leaves

View from A Picnic Table

Fall Colors: Part I – Yellow, Gold and Orange

Here in PA it’s the peak of the fall colors. Deciduous trees are transforming, leaving the green of spring and summer behind and turning into the bright yellows, reds and oranges of autumn. Seeing this change all around me, it got me thinking about what causes this change. So I did some research and found some fascination information about the fall colors.

The entire process begins with the tree knowing that winter is coming and that the growing season is about to end. I had always thought that the onset of the changes in leaf colors was due to the cooler days of autumn. But trees have evolved a much more reliable way of knowing when winter is on its way. Temperatures can vary from year to year but the one constant is the increasing length of night. As the days get shorter, the trees know it’s time to start shutting down and going into dormancy.

During the growing season there are two main pigments present in leaves of trees – chlorophyll and carotenoids. Chlorophyll is the green pigment that traps the sun’s energy and, through the process of photosynthesis, allows the leaves to produce sugars to feed the tree. Carotenoids are yellow/orange pigments that give carrots, bananas and corn their color. In the cells of leaves, both of these pigments are located in organelles called chloroplasts. The interaction between these two pigments is interesting. Chlorophyll is constantly breaking down and being replaced by the leaves. If this green pigment is exposed to the full energy of the sun with no protection, it’ll break down faster than the leaf can produce it. What protect the chlorophyll are the various carotenoids that are also present in the chloroplasts. These yellow pigments act as a “sun block,” absorbing some of the sun’s energy to protect the chlorophyll while still allowing enough energy to fuel photosynthesis. A leaf in the summer has a perfect balance of greens and yellows to allow it to feed the tree.

When the days become shorter, the leaves produce less chlorophyll until there is none left. When this happens, the carotenoids, which have been masked by the green pigments, are revealed and we see the yellow, gold and orange colors of autumn leaves.

Carotenoids Revealed

Since these carotenoids are always present in leaves, the display of yellow colors in the fall are fairly consistent from year to year. Environmental factors have little effect on them. The red, crimson and purple colors are a different story and I’ll explore them in my next post.

When I drive by a tree that’s exploded in bright yellows and golds, I’m seeing the carotenoids that have been in the leaves all year. But with the chlorophyll gone, these yellow pigments get their chance to shine. After spending all summer protecting the chlorophyll, I think it’s only appropriate that they have their moment of glory, short-lived as it might be.

Something I Learned while Driving….

As I drive around the area, I always have my eyes open to the various plants that people have in their yards. I often get ideas of plants to grow and ways to grow them from my PA neighbors.

For the past months I’ve been driving by one house and noticing these green plants growing in their front yard and by the mailbox. I wasn’t sure what they were since I was driving by each time I saw them. The plants were about 2-3′ tall and had no flowers.

Helianthus

That is until now. In late September those nice, manageable green plants started to grow. And grow. And grow. I then had an idea of what they were but now that they’ve topped out at 7′ and are covered with yellow flowers, I can finally identify these plants – they’re perennial sunflowers (Helianthus), probably maximilianii. This plant is sometimes called a prairie sunflower. They’re beautiful plants and you can’t help but notice them. The only problem is that their enormous height looks strange in the front yard and growing by the mailbox. And I don’t want to even think about what will happen to these plants if we have a wind storm!

I’m not writing this to mock the people who planted them – every gardener has planted a great plant in the wrong location. I put cottage marigolds along the walkway one year and the bushy plants took over and make it difficult to walk to the front door. I planted a euonymus (Euonymus japonicus)  in a shady corner of the house and it went wild. I had to cut it down and am still, years later, spraying small shoots of new growth with Round Up. I have another euonymus that has to go, Euonymus alatus, a winged burning bush. I planted it by the front door and between growing too large and always being covered with aphids, it’s just not worth the effort. (Maybe I need to stop trying to grow euonymus!)

Helianthus Flowers

In the right location, all of these plants would be fine but where I planted them, they just didn’t work. The same is true for the people with the helianthus. This behemoth is great in the back of a border or in a clump at the corner of a house. But by the mailbox , it’s just too big.

I’ve often thought of growing some Helianthus maximilianii but after seeing them in a neighbor’s yard, I know there isn’t a good spot for them in my garden. So I’ll cross that plant off of my “to grow” list.

Who knew you could learn so much about gardening just by keeping your eyes open while you’re driving?

Time to Start Bringing the Houseplants Inside

Philodendron

During the summer I put my larger foliage plants outside on the fire escape. It’s a western exposure but there’s a large oak tree that keeps the area shaded. I’ve found that plants like ficus, dracaena, philodendron and others do well in this location.

But when the weather gets cooler, I know it’s time to start bringing the plants back inside the house. But before I bring them inside, I want to make sure that I’m not bringing insects into the house. By this point in the season, the insects are slowing down but if I bring any into a warm house, they’ll come back to life with a vengeance and once they’re in the house, it’s hard to control them.

To make sure this doesn’t happen, I check the plants closely to see if there are any visible insects. If there are, I wipe them off the leaves and/or stems with a paper towel.

But even if I can’t see any insects, there can still be some living in the leaf whirls, hiding in the places where the petioles and stems meet or there may be eggs that I don’t notice. So while the plants are still outside, I spray them with an insecticide to kill any remaining insects.

In the past I would drench the plant with insecticidal soap, an organic product that you can find in any garden center. That worked pretty well but lately I’ve been using a systemic insecticide that contains imidacloprid. It’s available in a spray that’s quickly absorbed by the plants. It also comes in a granular formula that can be applied to the soil a few weeks before bringing the plants inside. The benefit of the granular formula is that it will also kill any insects in the soil and limit fungus gnats when the plants are in the house.

The final step before bringing the plants inside is to give them a shower. After a summer outside the leaves can get a little dirty so I put each plant in the shower and spray the top and bottom of all the leaves.

I have a few weeks before the plants have to come inside. It’s time to check for insects and apply the insecticide. The other thing I have to do is find a place to put all of the plants – that’s the truly hard part of bringing the plants inside!