Of potatoes and blue roses: be a mad plant tinkerer

A few weeks ago, I saw an interesting article in the Wall Street Journal (of all places) talking about people who are bioengineering plants at home to develop, among other things, a true blue rose.   I love to see this.  “Tinkerers” have long been a proud tradition of people who make true impacts and discoveries.  I think of the ultimate plant “mad tinkerer” Luther Burbank who established himself as a foremost expert on developing new plants all from his crazy tinkering that developed the potato that you’ll find at nearly every fast food joint and created plants such as the shasta daisy and the wonderberry.  I also think of a contemporary plant tinkerer – my friend and fellow GP Joseph Tychonievich.  I love seeing all of his new plants and envy his creativity.

I can only hope that more and more people, and younger people especially, have an interest in amateur plant science. We live in a time when science education has reached a fervor, with about every school and youth program focused on STEM education.  We even have 4-H clubs that meet in our office that are completely focused on robotics and coding.  While this focus on science is great, my issue is that it focuses mainly on the “sexy” disciplines (engineering, chemistry, physics, etc) and little on life sciences like plant biology.

I’m heartened to see many many schools adding gardens to incorporate into the curriculum.  Here in my county we’ve helped build and advise over two dozen school gardens.  I’ve also seen some new tools to inspire young plant scientists, including an online community of scientist mentors who give guidance to budding plant science students (Planting Science). Who knows, maybe we’ll inspire a new generation of Luther Burbanks.  We can only hope.

Is a tomato a fruit? Or a vegetable? Yes. And yes.

I’m not sure why this is the question that just won’t die, but I got it again at a event where I was speaking recently, so I am hereby going to issue the final, official, definitive ruling on the age-old question: Is a tomato is a fruit or a vegetable?

The answer is:…

(Drum roll please)


Fruit. And Vegetable. At the same time.
Fruit. And Vegetable. At the same time.

That’s right, folks. Vegetable and fruit are not mutually exclusive categories! Fruit is a technical, botanical term like leaf and petiole and petal which refers to a specific part of a plant. Vegetable is a cultural term referring to parts of plants that we eat.

In other words: lettuce is a leaf and a vegetable, celery is a petiole and a vegetable, broccoli is a flower bud and a vegetable, and a tomato is a fruit and a vegetable.

The real mystery to me is why this question always comes up around tomatoes and only tomatoes, when there are lots of other vegetable-fruits in the grocery store. Peppers, zucchini, pumpkins, eggplants, and cucumbers are ALL fruit. And vegetables. But somehow no one seems to wonder about them.

Joseph Tychonievich

Why you (probably) shouldn’t be starting seeds yet

As a beginning gardener I learned that to give plants like tomatoes and peppers more time to grow and produce the largest possible crop, it was best to start the seeds early indoors.

gazaniaseedlingsAs soon as I learned that, I wondered: Well, if starting my tomatoes 6-8 weeks before transplanting them outside is good, surely 10 weeks would be better, right? Or 12? Or 16?

Turns out, earlier isn’t always better, and here are some of the reasons why.

First, you probably don’t have enough light. If, like most home gardeners, you are starting seeds under florescent bulbs, it is difficult to give sun lovers like tomatoes and peppers enough light. Light intensity drops off rapidly as you move away from the bulbs, so you know to keep the bulbs right above your seedlings. This works great when the plants are small, but as they grow it becomes very difficult to give both the tops and the bottoms of the seedlings enough light. The result is dying lower leaves and spindly, unhealthy growth.

rootboundSecondly, you are almost certainly going to get some crappy root systems. If you’ve followed this blog for a while, you’ve no doubt read Bert and Linda talking about all the potential problems with the root systems of container grown trees and shrubs. Well, most of the same problems develop with other plants grown in small containers. The roots start circling and they are slow to grow out of the rich soil of the container and into the native soil around them once transplanted into the garden. The longer your transplants grow indoors, the more likely they are to develop problematic root systems. Keeping transplanting them up to larger and larger containers can help mitigate the problem, but that quickly takes up far more space than most home gardeners have for there seedlings.

How big and impact that circling root system will have on the health of the plant varies by species. My personal experience growing zinnias, for example, is that they handle circling, pot-bound roots so poorly that plants from seeds sown directly in the garden quickly over-take and out-perform plants started weeks earlier indoors.

So follow the recommendations for the timing of seed starting. It really does work better. You should be able to get advice on when to start seeds from the catalogs you are shopping, extension offices, or you can use Margaret Roach’s excellent seed sowing calculator.

If you DO decide that earlier is better, that you can provide the light and generous pot sizes to avoid problems, there’s no harm in giving it a shot. But if you do, try starting a second batch at the later, recommended, time and growing the two side-by-side in the garden so you can really compare and see which perform best in the actual conditions of your garden, and if all that extra time and space under your lights or in your greenhouse was really worth it.

Joseph Tychonievich

Not raking leaves: Too good to be true?

Rejoice, gardeners and homeowners, for your deliverance from the drudgery of raking leaves has arrived. Or so goes the proclamation from a viral article that popped up on social media this past fall.

The article in question was posted on the Woman’s Day magazine website based on information from the National Wildlife Federation As the article points out, leaving piles of leaves on the lawn are good “habitat” and homeowners should just let the leaves fall where they may for the sake of supporting critters in the lawn. Of course, you can always believe everything you see online, right?  Let’s take a look at what research can tell us.

Not so fast. There are a few issues with this new proclamation. Not that I am a great fan of the rites of autumn that dictate that we remove leaves from the lawn. It is one of my least favorite garden tasks, as evidenced by the fact that I wait until every last leaf has fallen before I get the leaf blower out so I’m certain that I don’t have to do it more than once.

Many people rake up leaves in the lawn because of aesthetics — we don’t want our neighbors to see a messy lawn. But there are lots of other issues that leaving leaves on the lawn can cause. Let’s take a look at all the reasons why leaving a layer of leaves on the lawn may not be the best idea.

First, the claim that leaving leaves where the fall on the lawn provides “habitat” for wildlife. What wildlife? The original source suggests small mammals, butterflies, and moths — specifically providing a place for overwintering. While I’m sure that there are some perfectly nice little critters that will make their home in the leaf litter, I have a name for what a lot of those things that find their home in your new “habitat” may be— pests.

Plant debris provides excellent overwintering opportunities for many garden pests. I also suspect that some of the wildlife that would find a comfy abode in the leaf litter would be small rodents, like mice and voles, that would enjoy nothing more than to snack upon some of the woody plants in your landscape. I also found some research that says removing leaf litter from residential areas reduces populations of ticks (article). Definitely something I wouldn’t want to welcome with open arms to my lawn.

Now let’s think about how plants make their food — they use sunlight for the process of photosynthesis. The article in question advocates letting leaves pile up where they fall on the lawn.  This means piling up on the grass (or in my case, whatever passes for green).  A layer of leaves on top of the grass will inhibit the plants from making their own food. While grass may not be actively growing in the winter, as long as it is green, it can still perform photosynthesis and store the food for spring. Even if you have a species of grass that turns brown in the winter, a pile of leaves would become an issue when things warm up in the spring.

It also turns out that a thick layer of matted leaves on top of the soil can create a barrier that reduces oxygen in the soil — thus creating an anoxic condition that will reduce or damage roots. Not only do the leaves create a barrier, but research has shown that the rapid consumption of oxygen by leaf litter bacteria lead to anaerobic conditions in the leaf litter itself (article).

Give the reduction in sunlight and soil oxygen, grass can have a difficult time thriving in areas of heavy leaf litter. Some other research results I found indicate a layer of leaf litter reduces the amount of herbaceous plants (in woodland) (in a field study). If you think about it, you don’t see many small herbaceous understory plants in forests with lots of trees — it isn’t just the shade from the trees that causes a problem.

I’ll also point out that for dog owners, leaving a layer in the yard can make it much easier to fall prey to what we refer to as “yard bombs.” I’m sure other dog owners have felt this pain.

Now, I’ll be the first to tell you that leaves are a valuable resource for lawn and gardener, so don’t think that I’m anti-leaf. I put all of the leaves that fall in my yard to work for me. While leaving the leaves to pile up into layers on the lawn is not a good idea, using a mower to chip them up and leave them in place will provide valuable organic matter and nutrients for the soil. So if you don’t want to rake them up, run over them with the lawnmower so they will break down quickly into the soil (and don’t smother out the grass).

If you do rake up (or vacuum up) the leaves, there are a few things you can do with them. First, the shredded leaves make a good winter mulch for landscape beds (put the plant suppressing power to work controlling weeds). You can also bag them up and store them for use in composting next spring and summer when you have fresh green plants to add to them.

This article originally appeared in the Charleston Gazette-Mail on November 15 (sans citations).  

You can find my other articles online at wvgardenguru.com


Our brightly colored world

By Dr. John Palka (from his blog site)

We are now headed into the dark part of the year. The winter solstice is less than a month away. For the moment, however, let us think not about these short days and long nights, but back to the summer—and especially to summer’s brilliant flowers. How do all these colors come to be? What allows us to perceive them? Why don’t we see the world in the black-and-white of old-style photographs?

Let’s start our exploration of these questions in the northwestern corner of Washington’s Puget Sound, a stone’s throw from the Canadian border. Here lie the San Juan Islands, hundreds of islands, islets, and projecting rocks so beautiful that people sometimes ride the ferry just to glimpse them from the deck, never even getting off to walk on land. These complex and convoluted landforms are home to thousands of birds and marine mammals, their shores are decorated with exotic-looking creatures bumping up on one another, and every bit of soil is covered with rich vegetation—stands of Douglas fir and cedar, a bright coastal fringe of madrones with their vivid red-orange bark and brilliant white blossoms, and grasses that turn golden with the advance of summer. In the spring the islands are carpeted with wildflowers, and none more richly than eleven-acre Yellow Island.

Yellow Island has been owned and protected by The Nature Conservancy since 1979. Its flora is basically intact, the way it once was on all the islands, and in the spring it is brilliant.

The masses of yellow that give the island its name are buttercups.

The photographer finds it hard to move forward, there are so many sights to delight the eye and invite a picture. The biologist is thrilled that such a place still exists, so close to the densely settled metropolis of Seattle and its surrounding cities. And I, in addition to these feelings, find myself marveling at the colors themselves.

The purplish-blue camas lily, prized by Native Americans for its edible bulbs, abounds.
As does the brilliant red Indian paintbrush.

All the Colors of the Rainbow

The plants on Yellow Island glow with literally all the colors of the rainbow, from blue, through green and yellow, and on to orange and red. They call out a question that scientists and philosophers have asked literally for centuries—how do leaves and flowers come to have the colors they do? Indeed, why are objects of any kind seen by us as having distinguishable colors?

The sensation of color is an everyday aspect of conscious experience for most of us, but what makes it so? It needn’t be, for we are all familiar with a world without color, as portrayed in the marvelously evocative black-and-white prints of master photographers. It is also different for those who have some form of colorblindness.

For us to experience a colored world requires the operation of many mechanisms, not all of which are understood by today’s science. The foundation of the entire complex chain of processes leading to conscious experience is, however, the interaction of light with molecules. Inasmuch as there are two partners in this interaction—light, and the molecules that are affected by light—we will need to consider both of them.

Let’s start with light, particularly sunlight, the natural light in whose presence all life on Earth evolved. Thermonuclear reactions occurring within the Sun emit massive amounts of energy that streams out in all directions, through the solar system and beyond. The total quantity of solar energy reaching the Earth is just right to warm the planet to a temperature that has enabled the evolution of life. It arrives on Earth’s surface in the form of a vast range of wavelengths of electromagnetic energy, from the extremely short-wavelength and highly energetic gamma rays and X-rays at one extreme, to the long- wavelength, low energy radio waves at the other. Between these two ends of the total electromagnetic spectrum the ratio of wavelengths (and hence also of energies) is 1018, or 1 followed by 18 zeros. Gamma rays are of atomic dimensions, so short that we have no sensory experience to compare them to, while radio waves are measured in miles. Nevertheless, their basic nature is the same. Extraordinary!

Visible light is a tiny, tiny slice of wavelengths in the middle of this vast range, with ultraviolet (sunburn!) just to the shorter wavelength side, and infrared (heat!) to the longer wavelength side. The spectrum that underlies our experience of light and of the visible world runs from violet to red. Here is what this spectrum looks like on the ceiling of a friend’s apartment, with the colors separated by a faceted glass ball she has hanging in her west-facing window.

spectrumAnd here is the same spectrum seen in a rainbow over the rolling plains of Montana, north of Yellowstone National Park.

Rainbows and Flowers

The sunlight that reaches our Earth literally consists of all the colors of the rainbow. But what about the flowers? How do we relate the colors contained within the apparently colorless light that is shining on a meadow to the colors we experience as being the property of the buttercups, the camas, and the paintbrushes?

To come to a deeper understanding, think about a colored liquid that you can handle easily yourself, say red food coloring. You grasp the tiny bottle, squeeze a few drops into a small glass of water, and voilà, you have red water. White light shining in from one side of the glass emerges as red light from the other side. Test it. If you let light shine through the glass and onto a sheet of white paper, you will see a patch of red.

What happened to turn the white light that entered the glass into the red light that exited? When light struck the dye molecules that were dissolved in otherwise colorless water, some wavelengths of light were selectively absorbed. If they were absorbed, they could no longer pass through the solution and be seen on the other side. The color of the light exiting from the solution, therefore, is due to the wavelengths that were not absorbed.

This is a bedrock principle that underlies our experience of color, and that we will explore in several subsequent posts. Molecules absorb some wavelengths of light and fail to absorb others, and the wavelengths that are not absorbed are ones that can reach our eyes and be seen. Notice that there are two partners dancing to manifest this principle, the light and the molecules absorbing the light. This partner dance will be our foundation as we explore the amazing realm of color. For now, just go out into the world and pay attention to the colors you see, being grateful for the privilege.

Blast from my petunia past

A few days ago I recorded a podcast with Margaret Roach were we talked about all our favorite seed sources. One of the many things we mentioned were the great species petunias available from Select Seeds. Which caused me to flash back to my time in graduate school doing research on petunias, and dig up these old images.

Petunia integrifolia (top left) Petunia axillaris (top right) and their F2 hybrids (everything else)
Petunia integrifolia (top left) Petunia axillaris (top right) and their F2 hybrids (everything else)

At the top are Petunia integrifolia (purple) and Petunia axillaris (white) and below are an assortment of flowers from a population of F2 hybrids between the two. This cross is interesting because it is a recreation of the original hybrid that created modern hybrid petunia.

Petunia exserta (top left) Petunia axillaris (top right) and their F2 hybrids (everything else)
Petunia exserta (top left) Petunia axillaris (top right) and their F2 hybrids (everything else)

But more fun is a similar cross with the one hummingbird pollinated petunia, P. exserta! It is fun to see the ways the colors and flower forms recombine in new ways in the seedlings.
I don’t have anything profound to say about these pictures… just, hey, isn’t genetics cool?
Joseph Tychonievich