31 December 2010

Friday Cartoon: News Years Resolutions

newyearsresolutions

For more silliness on new years resolutions for gardeners, do check out this post from the lovely Carol of May Dreams Gardens.

29 December 2010

Yet another reason to GROW your dinner.


This article in Wired caught my eye a while ago, and I'm just now getting around to blogging about it. It talks about some studies which indicate that the more we work for our food, the better it tastes, the more we enjoy it. Most interestingly, this isn't just a higher level psychological feeling of satisfaction -- the same apparently holds true for mice, indicating this may be a pretty fundamental part of how brains work.
That's interesting, but it gets more interesting. Work with brain scanning indicates that obese people get less pleasure from food than people with a healthy weight -- implying that they may be overweight because they have to eat more to get the same level of satisfaction.
In this article, they put that together to say that taking time to cook dinner will make it taste better, and therefore help you eat less and be healthier.
I'm inclined to take it a step further: A home cooked, home GROWN meal is quite the peak of deliciousness, leaving one so flushed with pleasure the thought of an oreo orgy can hardly come to mind and McDonalds sounds simply repulsive.
 As if I needed another reason to keep vegetable gardening...

19 December 2010

Sedums were (apparently) hot in 1810

I know I said I was taking this week off blogging, but this is just too fun not to share.
I've been playing with Google Ngram viewer. Basically, google has scanned a huge number of books, and you can search the entire database to see how often a word has been written in the past 200+ years. It is fascinating, and kind of addictive, giving a little window on how much we write and think about different topics.

Here is a chart of the use of "garden" (blue) and "television" (red) from 1800 to 2008
I love where the garden trend is going! Higher than it has been since the 1950s, and eclipsing television for the first time since the '70s. My generation is coming of age, and we're gardening it up!


It is also fun to look at individual plants. Here's hosta:
Maybe the hosta craze is (finally) over?

Heuchera is still going strong:


Turning to tender bulbs, here are dahlia (blue) and gladiolus (red)
I think it is high time for a come back...


In light of the current mania for succulents, I typed in "sedum"
The recent rise, I expected. But a huge spike in 1810? Who knew?
I could keep going on and on... I'm not sure how meaningful this data actually is, but it sure is fun to play with. Play with it yourself here and be sure to let me know in the comments what your favorite results are! (BTW, if you want to recreate my results, you'll have to change to search from 1800 to 2008 -- the default is 1800-2000)

17 December 2010

Friday cartoon: Gardener dreams

Merry Christmas everyone! (Unless you don't celebrate it, in which case, Happy Whatever Suits Your Fancy!)
The night before Christmas
I'm taking next week off blogging for the holidays, so I'll see you all in a week or so.

13 December 2010

Sciency Answer: Variegated plants are liars

Dear Mister Greensparrow Gardens Person:

I have a SCIENCE QUESTION (dah duhduh DAAAH) about variegation. Isn't the point of a plant being green for good light wavelength absorbency? I mean, plants that are other colors besides green still absorb most of the spectrum because of different kinds of chlorophyll, etc. But what about the plants that are variegated to have mainly white leaves? What is up with that? Doesn't the color "white" mean that all the wavelengths are reflected back? So how would they photosynthesize properly if they couldn't trap light efficiently? With some of these plants, there is still some green or other color, but it doesn't seem like it would be enough to support such a big plant. 

-Hannah

You are absolutely right -- completely white sectors on leaves don't photosynthesize, and plants that produce whiter leaves are going to be inherently less vigorous than ones with green leaves. So why are they like that?

Most variegated plants are essentially man-made -- they are unhealthy, mutant freaks that would die if we didn't like them and keep them alive in our gardens. Sort of like chihuahuas (except chihuahuas are disgusting and variegated plants are delightful.) Surprisingly, however, some wild plants, like some caladium, begonia, and dieffenbachia naturally have white patches on their leaves. Breeding has increased the amount of white on the plants we grow, but still, the wild plant have distinct white patches on their leaves. Why?

Because they are liars.

Imagine for a moment that you are a expecting mommy-to-be leaf miner. You are flying about, looking for a good leaf on which to lay your eggs so your babies can happily start eating away at them. First you see a leaf like this:

photo credit
This leaf is already infested with leaf miners. Lay your eggs on that leaf, and your babies will starve, because there isn't enough leaf to go around. So you keep flying, and see a healthy, green leaf like this:



This looks perfect! You land, and lay some of your eggs, and then happily fly on to find a home for the rest of your brood. But the next leaf you see looks like this:
photo credit
This leaf looks TERRIBLE! There must be a million leaf miners and caterpillars already there, munching away for this leaf to have so little green on it. So you fly on... fooled by a sneaky, variegated plant. The plant has made a trade off: less efficient photosynthesis in exchange for not being eaten alive.

In other words, natural leaf variegation is the plant equivalent of pretending you have whiplash in order to get insurance money. This is a fact that should make those of you who don't like variegated plants because they look unhealthy rethink your position. That is just what those plants WANT you to think! You are being fooled, just like the little leaf miners. Go buy some today just to show those plants you are smarter than them.

If you want more of the science behind white leaves, here are some good papers (subscriptions required):
The history of research on white-green variegated plants
Ecology of a leaf color polymorphism in a tropical forest species
Leaf variegation in Caladium steudnerifolium (Araceae): a case of mimicry?

Have a question? Get a sciency answer! Just e-mail me: engeizuki at gmail dot com

08 December 2010

My Top 5 Gardening Books

Genevieve is asking garden bloggers to list their top 5 gardening books -- just in time for winter book season!


Here is my list: 


The Explorer's Garden by Dan Hinkley
There are actually two of these -- one on perennials, one on shrubs and vines. Both are amazing, but I have a personal love for the first one, on perennials, because that was the book I stumbled upon as a beginning gardener who grew nothing but roses (for SOME insane reason) and that book opened up for me this whole other universe of growing, loving and collecting plants. To me, this book contains the magical essence of gardening as a passion, as a way of life. 


Gardening on Pavement, Tables, and Hard Surfaces by George Schenk
Okay. Just read that title. What? Gardening on tables? Hard surfaces? What does it mean? Don't get this book from the library, but buy your own copy, because it will blow your mind right out of your nose and all over the page, and librarians frown on this. Container gardening without the container. Floating table top gardens. Lawn you can roll up like a carpet. 


My Garden (Book) by Jamaica Kincaid
This book takes you right inside Jamaica Kincaid's mind while she gardens, and what you find there is a wild, exhilarating, poetic, funny, moving, swirl of images, stories, ideas, plants, and places. Which is a terrible description, but this book is indescribable. And wonderful.


A Pattern Language by Christopher Alexander, Sara Ishikawa, and Murray Silverstein
The subtitle to this book is "Towns Buildings Construction." So... why is it in my list of top gardening books? Because good design is good design, and these principles are universal. An example: I just flipped my copy open at random, and this is what I read: "Do not be tricked into believing that modern decor must be slick or psychedelic or 'natural' or 'modern art' or 'plants' or anything else that current taste-makers claim. It is most beautiful when it comes straight from your life -- the things you care for, the things that tell your story." There are over a thousand pages of truths like that. Go dig in. You'll garden -- and live -- differently for it.


Merry Hall by Beverly Nichols
I've reviewed this book before so I won't say too much, except: This is a must for any gardener. It captures so perfectly the JOY of gardening, the sheer bliss of this most wonderful of passions. 


So that's my list! What are you five favorites?

06 December 2010

Sciency Answer: Seed cleaning and sprouting

Today's question is from Keith Long, brought on by a comment this post on his blog:

My question is about Rhodochiton astrosanguineum seeds.
When you buy these they're very small seeds with the husk (of each seed) removed. Yet the germination rate is very poor. Either that or the the type of people who buy them clearly are incapable of following their instructions!
Yet once you have a plant, and have collected the seeds, the germination rate is near 100%. Clearly, I don't mess about removing the individual seed husk, I just put the seeds in. The seeds in their husk are nearly the size of a chilli seed.
Why are they husked? Why does this lead to such a low rate of germination? And merely out of interest, how on earth do they do it without losing the minute seeds?

The factor here is almost certainly not the husk covering the seed, but the freshness of the seeds. Many seeds rapidly loose their viability, and need to be sown right away, while others simply start taking longer to germinate the longer they sit around dry. Based on my poking around, it appears that very fresh Rhodochiton seeds germinate rapidly and easily, while older seeds will still sprout, it just takes significantly longer.

Which makes one wonder... why would seeds do that?

A gardener, of course, wants every seed to sprout as soon as it is planted. But in the wild, plants need to be more careful. If every seed sprouts right away, one flood or late frost can wipe out the entire next generation. So most wild plants have various tricks to ensure seeds don't germinate all at once, or germinate at the best possible time. For a plant like Rhodochiton, fresh seed that falls on moist soil will sprout right away, getting a quick start on the next generation. But any seeds get a chance to sit dry for a while drop into a deeper dormancy and hang around without sprouting, acting as a sort of insurance policy to make sure there are still seeds around if something happens to those that have already germinated -- much as gardeners usually don't plant the whole packet at once in case of damping off.
How readily or uniformly seeds sprout often depends on the climate they evolved in. Plants from desert areas with erratic rainfall are notoriously hard to get good germination from, instead one seed at a time will sprout over a very long period -- extreme insurance for a difficult, erratic climate. Plants from wetter, more predictable climates tend to have seeds that sprout more uniformly.
Plants that have been grown for a long time by humans almost always develop quick and uniform germination because without even trying to, we tend to select the individuals that sprout first. If you sow 100 seeds, and 10 sprout in a week, most people just prick out those ten and forget about the other 90, even though they may have eventually sprouted. Those quick germinating seeds will go on to have more rapidly germinating offspring, and so on, until they all sprout at once like most familiar annuals and vegetables.

To get to your other questions about removing the husks, seed companies usually remove them for a number of reasons: It looks neater and tidier in the seed packet, the cracks of crevices of the husks can offer ideal little hiding places for fungi. In some cases, it also allows the seed producers to get a good look at the seed itself and separate out small, shriveled seeds that are unlikely to germinate.
Cleaning off all the husks and chaff of seeds can be rather a pain. I worked for a while for the Ornamental Plant Germplasm Center, and spent quite a bit of time cleaning seeds. The first step is usually to gently rub the seed heads between to rubber blocks, which crushes and breaks up the seed husks. You can then separate the chaff from the seeds a number of ways. A fine sieve will let fine seed fall through but keep big chunks of chaff behind. We also had a cool machine which was basically a big plastic tube with a fan in it which allowed us to blow off the light chaff but leave denser seeds behind. Various other shaking, blowing, and sieving machines are used to rapidly get all the seeds in one pile and the other stuff in another. It is kind of cool, but when you are working with many different species as we were, you have to figure out the best machine and setting for each species, which can lead to a frustrating amount of trial and error.

Have a question? Get a sciency answer! Just e-mail me: engeizuki at gmail dot com

03 December 2010

01 December 2010

Science Answers: tap water versus rain water

Another great question from Annie of Annie's Annuals:

Is there something special about rain water ? I mean beyond "hydration"? As we are a Mediterranean climate here in the Bay Area, we have to use city water all Summer .  Then, after the first rain everything goes bonkers and all my garden plants seem to grow quite a bit overnight and vibrate with inner happiness.  No, I'm not currently on drugs and I swear this is true. I notice it every year. I know its not that they get watered deeply for the first time in a while- because our waterers  at the nursery water everything  every day whether I like it or not!  Can you solve my mystery?

I think I can solve your mystery. Let me start by telling you about another mystery.

Columbus Ohio has a lovely public conservatory which had a marvelous collection of palms. These palms had been happily, healthily growing for decades, then started mysteriously wasting away and dying. The workers at the conservatory hadn't started doing anything new, the plants weren't diseased or infested with insects. At a loss, they enlisting help from horticulture professors at Ohio State who determined the soil pH was WAY too high. Which was an answer, but lead to another question. They had been maintaining these palms the same way for decades, and everything had been fine. Why would the soil acidity suddenly get all out of wack?

Water.

The city, it turns out, gets water from three different treatment plants, and each uses water from different reservoirs and/or wells, making the water from each plant chemically different. As the city grows and changes, they sometimes switch a neighborhood from water from one plant to another, and they had changed the source for the conservatory's tap water -- but didn't mention it to them. After all, water is water, right? Nope. The new water source was radically more alkaline than the old one and suddenly all the plants that had been vibrating with inner happiness were stressed and dying. The conservatory started pH testing and treating their water with acid, and the remaining palms were saved though many beautiful trees had already died.

(a moment of silence for the palms)

The sad story of the palms goes to show that sources of water can be pretty radically different and have a big effect on plants. Truly pure water essentially doesn't exist. Water is sometimes called the universal solvent because almost anything can, and does, dissolve into it. Even ultra-super-extra-triple distilled water won't stay perfectly pure for long. As soon as it is exposed to air, carbon dioxide will dissolve into it and make it slightly acidic. So don't be fooled by "pure" bottled waters. If it was truly pure, it would cost a lot more (ultrapure, research-grade water costs about $25 a liter), and besides, extremely pure water tastes unpleasant, and isn't good for you.

City water comes from various sources like wells, lakes, rivers and treated sewage (yum...) and picks up all sorts of different minerals, salts, and gasses along the way. Water treatment plants remove some of those compounds, add others, and sterilize it to make it safe for people to drink. The emphasis here is on people, and some water treatments aren't all that good for plants. Some plants are sensitive to chlorine, and water softeners take out excess dissolved minerals in water (which are mostly fine for people or plants) and by replacing them with dissolved salts (which are very bad for plants). Rain water generally has less stuff dissolved in it than tap water, but it isn't pure either, not by a long shot. Clouds contain not just water, but also various dust, gasses, and (unfortunately) industrial air pollution, making rain water chemically different than tap water.

So how might the difference between rain water and tap water be effecting your plants? As demonstrated by the palm story I started with, pH could be a big one. Rain water is slightly acidic (or not so slightly, if you've got acid rain) whereas most tap water is alkaline due to dissolved minerals. It may be that over the summer your soil pH slowly goes up, out of the plant comfort zone, and then gets brought back down with the arrival of the fall rains. You could test this theory pretty easily be measuring your pH before and after the rains start.

Another option would be mineral and salt build up. Most tap water contains a fair amount of dissolved minerals, and fertilizers (of any sort -- organic or synthetic) are salts. As water evaporates from the soil, it leaves the minerals and salts behind, which over time can affect the health of the plants. In extreme cases, like house plant that have been around forever, you might even see a crusty white layer on the surface of the soil. Rain water is purer than most tap water, and coming in large amounts could flush out the excess minerals and salts letting plants grow more happily. You could sort of test this one by comparing your soil's salt concentration before and after the rains with an EC (electical condictivity) meter.

It could also be nitrogen. I didn't realize this until I started researching this answer, but rain water can have significant amounts of nitrogen in it (but, then again, so can tap water, especially in agricultural areas). The papers I've looked at on the subject find the amount to be pretty variable by region and season, so your local fall rains may or may not be giving your plants a fertilizer boost along with hydration.

Finally, as I mentioned above, the water treatment process adds chemicals like chlorine to tap water, which some plants are sensitive to. These may be slowly building up in the soil over the watering season gradually hurting the health of the plant.

In short, rain water is very different from most tap water, and the "inner happiness" your plant exhibit with the arrival of fall rains isn't a figment of your imagination nor a drug-addled hallucination, though it is hard to say for sure which factor or combination of factors are responsible for their joy.

Have a question? Get a sciency answer! Just e-mail me: engeizuki at gmail dot com.