BLOG RERUN: Happy Diwali!

(a version of this blog post was originally published on November 13, 2012)

Diwali is officially tomorrow, but I might not be in a position to post a new blog tomorrow. Instead of posting a Diwali celebration blog a day late, I figured it's better to post it a day early! Happy Diwali! :)

Species name: Tagetes sp. (probably T. patula)

Common name: marigold

Location: picture 1 is from Teaching College English (click HERE), picture 2 is from eHow (click HERE), and picture 3 is from the WikiJunior Flower Alphabet (click HERE)

Tomorrow is the first day of a five-day celebration by Hindus, Sikhs, and Jains in India and around the world. It is known as the "festival of lights" or Diwali (or Deepavali, depending on what part of India you're from). I tried following how the exact date of Diwali is determined for any given year, but got lost after the mention of lunar days. For us non-Indians, it's sometime between mid-October and mid-November. This year it happens to be on November 3rd. So how does this relate to a blog about plants, when it's a celebration of lights? Well, read on...

With over a billion people of the world celebrating Diwali, and with it being the single most important holiday to Indians around the world, there is an enormous demand for decorations. Just like North Americans decorate for Christmas or Hanukkah (or whatever else you celebrate), Indians decorate for Diwali. And like any true Indian celebration, A LOT of flowers are involved. In fact, there are so many flowers involved in any Diwali household celebration that the demand for flowers in India skyrockets; a flower arrangement selling for 30-50 rupees on any non-Diwali day would sell for between 700-900 rupees tomorrow. I encourage you to name any other commodity in the world whose value increases that much over such a short time, just to fall right back down to what it was all within a week. There are people in India who make their entire year's salary in one week. It's an incredible phenomenon! So how does this relate to marigolds? Well, quite unusually, it turns out.

Normally, the celebration of Diwali involves decorating the ground in a specific pattern with rose petals. Because of the unfavourable weather earlier this year, roses are in short supply compared to what they usually are, and on a day like Diwali when there's a surge in demand, flower suppliers just can't keep up. They knew well in advance that there would be no way they could meet demands, and so substitutes needed to be made. Marigolds were always popular flowers around Diwali because of their colours, but this year they became extra valuable. The value of marigolds increased almost one hundred-fold for this year's celebration alone! Could there be a day that climate change causes a huge shift in how festivals like Diwali are celebrated? Perhaps. The flower supply market in Kenya, one of the leading producers of carnations, roses, gerbera daisies and baby's breath worldwide, has already started to suffer as a result of increased incidence of drought. While the temperature is not expected to change much (only 2-3 degrees Celcius by the year 2100; compare that to a projected 7-8 degree change for the Arctic), the incidence of severe weather patterns is expected to increase. Drought will be more widespread and worse than it is now, and when there is drought relief it is expected to be in the form of violent storms. Not exactly weather conducive for flower growing, in a greenhouse or not.

Marigolds themselves are some of the most highly praised garden plants worldwide. They are native to North and South America depending on species, but were spread worldwide for ornamental plant use by early world explorers. Marigold petals are added to a wide variety of food items for the golden colour they give off, especially when fed to chickens. It brightens the colour of the egg yolk and makes the egg appear (to humans; chickens don't care about the colour of their yolks) to be more nutritious even though the nutrition hasn't been changed at all. Marigold petals are also popular in herbal teas to balance out the bright pink colour of so many other herbal tea ingredients (like rosehips or hibiscus petals). The roots of marigold plants are full of antifungal and antibacterial chemicals called thiophenes, which are starting to be investigated as chemicals of possible medicinal value. The roots have been used for centuries by Native South Americans as treatment for fungal infections of their agricultural crops with moderate success. Unfortunately, North Americans and Europeans found out this antimicrobial effect the hard way; when planted near legumes, which rely very heavily on microbial activity in the soil, the yield of the crop decreases dramatically. The scent of marigold flowers is so pungent that it repels a wide variety of crop predators, and so can be useful when planted beside non-legume crops like tomatoes, potatoes, eggplant and peppers. The flowers of the marigold plant also attract pollinators, some of which will also eat insect parasites of crop plants like aphids. A great story of insect-plant mutualisms!

Happy Diwali to all of my blog readers in India, and Indians living around the world! Diwali ki Subhkamnayein! That's the best I can do...my keyboard doesn't speak Hindi :)

Happy Diwali!

Species name: Tagetes sp. (probably T. patula)

Common name: marigold

Location: picture 1 is from Teaching College English (click HERE), picture 2 is from eHow (click HERE), and picture 3 is from the WikiJunior Flower Alphabet (click HERE)

First of all, I would just like to address the third image, and the fact that Wiki now has a flower alphabet meant to teach children not only how to identify flowers, but also teach them the alphabet and how to read. Are you kidding?! Way to go, Wikipedia! I am SO impressed. With that out of the way...!

Today is the first day of a five-day celebration by Hindus, Sikhs, and Jains in India and around the world. It is known as the "festival of lights" or Diwali (or Deepavali, depending on what part of India you're from). I tried following how the exact date of Diwali is determined for any given year, but got lost after the mention of lunar days. For us non-Indians, it's sometime between mid-October and mid-November. This year it happens to be on November 13th. So how does this relate to a blog about plants, when it's a celebration of lights? Well, read on...

With over a billion people of the world celebrating Diwali, and with it being the single most important holiday to Indians around the world, there is an enormous demand for decorations. Just like North Americans decorate for Christmas or Hanukkah (or whatever else you celebrate), Indians decorate for Diwali. And like any true Indian celebration, A LOT of flowers are involved. In fact, there are so many flowers involved in any Diwali household celebration that the demand for flowers in India skyrockets; a flower arrangement selling for 30-50 rupees on any non-Diwali day would sell for between 700-900 rupees today. I encourage you to name any other commodity in the world whose value increases that much over such a short time, just to fall right back down to what it was all within a week. There are people in India who make their entire year's salary in one week. It's an incredible phenomenon! So how does this relate to marigolds? Well, quite unusually, it turns out.

Normally, the celebration of Diwali involves decorating the ground in a specific pattern with rose petals. Because of the unfavourable weather earlier this year, roses are in short supply compared to what they usually are, and on a day like Diwali when there's a surge in demand, flower suppliers just can't keep up. They knew well in advance that there would be no way they could meet demands, and so substitutes needed to be made. Marigolds were always popular flowers around Diwali because of their colours, but this year they became extra valuable. The value of marigolds increased almost one hundred-fold for this year's celebration alone! Could there be a day that climate change causes a huge shift in how festivals like Diwali are celebrated? Perhaps. The flower supply market in Kenya, one of the leading producers of carnations, roses, gerbera daisies and baby's breath worldwide, has already started to suffer as a result of increased incidence of drought. While the temperature is not expected to change much (only 2-3 degrees Celcius by the year 2100; compare that to a projected 7-8 degree change for the Arctic), the incidence of severe weather patterns is expected to increase. Drought will be more widespread and worse than it is now, and when there is drought relief it is expected to be in the form of violent storms. Not exactly weather conducive for flower growing, in a greenhouse or not.

Marigolds themselves are some of the most highly praised garden plants worldwide. They are native to North and South America depending on species, but were spread worldwide for ornamental plant use by early world explorers. Marigold petals are added to a wide variety of food items for the golden colour they give off, especially when fed to chickens. It brightens the colour of the egg yolk and makes the egg appear (to humans; chickens don't care about the colour of their yolks) to be more nutritious even though the nutrition hasn't been changed at all. Marigold petals are also popular in herbal teas to balance out the bright pink colour of so many other herbal tea ingredients (like rosehips). The roots of marigold plants are full of antifungal and antibacterial chemicals called thiophenes, which are starting to be investigated as chemicals of possible medicinal value. The roots have been used for centuries by Native South Americans as treatment for fungal infections of their agricultural crops with moderate success. Unfortunately, North Americans and Europeans found out this antimicrobial effect the hard way; when planted near legumes, which rely very heavily on microbial activity in the soil, the yield of the crop decreases dramatically. The scent of marigold flowers is so pungent that it repels a wide variety of crop predators, and so can be useful when planted beside non-legume crops like tomatoes, potatoes, eggplant and peppers. The flowers of the marigold plant also attract pollinators, some of which will also eat insect parasites of crop plants like aphids. A great story of insect-plant mutualisms!

Happy Diwali to all of my blog readers in India, and Indians living around the world! Diwali ki Subhkamnayein! That's the best I can do...my keyboard doesn't speak Hindi :)

The oak of champions

Species name: Quercus rubra

Common name: Red oak, champion oak

Location: Ontario

The red oak, who's "official" common name is actually the Northern Red Oak, is native to North America, specifically the northeastern United States and southeastern Canada. It is a popular ornamental and lumber tree worldwide, and has been spread across Europe and Asia. It's also the state tree of New Jersey.

The pictures I selected to showcase the red oak aren't exactly your typical tree pictures. We had three oak trees growing in the front yard: one angled slightly over the neighbour's driveway (they never park there anyway), one angled slightly over our driveway (it's just a car!), and one angled slightly over the house (...it's just a house?). Since the one angled slightly over the house swayed more than just a little in the wind, it was decided that it would probably be best to cut it down. The top picture is what's left of "Curly" from our Three Stooges trees. Upon closer inspection (middle picture), the stump actually shows some pretty cool things about red oak trees! Even using a regular camera lens, you can actually see some of the cells that make up oak wood since they're so large. These cells are present in all trees, just larger in some than others, and are called vessels. Along with tracheids, they are the two types of cells that conduct water up the tree from the roots to the leaves. What most people don't know is that the only part of the tracheid and vessel system is still useful in a tree, and that's what's on the very outside of the tree. Trees actually grow by adding a new layer of wood to the outside of the tree, pushing the bark further outwards (which is why bark cracks and has ridges in it!). So that "old wive's tale" that you shouldn't carve your name into a tree because it might die? It's true! Injuring any part of the new growth of a tree leaves it open to infection even if there's still enough remaining wood for water transport.

Another neat thing that you can see from this tree stump is the ring pattern itself. Not all tree rings are created equal! In temperate areas, we always have trees with rings. Tree rings are created by the tree's generation of new tracheid cells. These tracheids are larger in the spring because there's lots of water and nutrients around, and smaller in the summer because of the lack of water. This makes a difference in density of the wood, creating what looks like stripes in the wood to our eyes but are actually just gradients of different sized cells. Red oaks are also what we call "ring porous," where all of the vessels are restricted to the spring wood, giving an even more distinct ringed appearance of the wood (which also gives a more pronounced grain when turned into furniture or flooring).

The last picture shows a phenomenon called "oak apple," which is the result of a parasitic wasp called the gall wasp laying eggs inside the plant tissue. This causes the plant to release wounding hormones at the site, which then causes tissue to be rebuilt. The gall wasp exploits this reaction by the larvae injecting these hormones continuously into the plant, causing the plant to make a bigger and bigger gall or apple. Once the larvae have matured, they bore a tunnel out of the gall, moult on the gall surface into the adult form, and fly away. In general, oak gall won't kill or otherwise harm the tree except in localized areas. If you're planning on growing a "show tree," the oak apples themselves are not very sightly. But if you do happen to have them, you should be thankful! Oak apples are one of the sources of a reddish-brown pigment used as ink ever since the Middle Ages, and they're actually the main source of ink for some of the oldest, most important texts of modern times. Now you know!