30 November 2011

Sciency Answers: How multicolor corn works

During Thanksgiving, people must have spent some time looking at decorations involving multicolored ears of corn, because I got several questions all essentially asking, What is up with that? How does a single ear can have many different colors on it, while you never see, for example, a single plant producing yellow, red and purple tomatoes? How does corn pull it off?
Corn does it the same way my parents had five kids, ranging from brown-eyed, brown haired me to my blond blue-eyed brother, with a smattering of hazel eyes and light brown/dark blond siblings in between. In other words, when you look at an ear of corn, you are looking at the next generation, and the genetics of each individual seed determines what color it is. With a tomato or any other fruit, what you see is produced by the mother plant, so it looks the same no matter the genetics of the seeds inside, just as my mother's pregnant belly looked the same whether that particular baby was a blond or brunette. But since each kernal of corn is a seed, you get a preview of the next generation.

As a gardener, and enthusiastic backyard plant breeder, I think this is one of the most fun things about corn. You get a little preview of the next generation before you plant the seed. Buy a mixed packet of petunia seeds and they'll all look the same, you have to plant them to find out what color they are. But when I buy different mixes of colored corn, I get to spend a very happy time sorting through them, picking out the colors I like best, so that when I plant them I get a customized mix of colors I like best.

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

21 November 2011

Creating New Heirlooms (Plus: Exciting news!)

Recently, I was telling a friend about my deep and abiding love for Russian tomatoes. I've grown several, and they have a distinctively rich flavor, often a beautiful dark color, and are well adapted for the cool, short summers of Michigan. 'Black Krim' is my favorite of the ones I've tried (though I think it is technically Ukrainian), and whenever I see the words like “heirloom from Russia” in a catalog, I pretty much know I'm going to like it.

That conversation got me thinking. I love Russian (and Ukrainian) tomatoes, but of course tomatoes don't really come from Europe at all. Tomatoes are native to South America, and, like a host of other delicious things (beans, squash, peppers, potatoes, eggplant, corn...) only made it to European gardens and tables after Columbus opened the new world to European explorers. Tomatoes, when they were first arrived in the old world, were a mix of varieties adapted to grow in warm South and Central American climates and selected for use in local food traditions and culture. Once they arrived in Europe, however, local gardeners took them on and made them their own. By saving seeds from varieties that performed well in their local climates and local cuisines, Italians created heat-loving, red, often green-shouldered varieties with a bright, clean taste, while Russians (and their neighbors) perfected cool tolerant, dark fleshed “black” tomatoes with a rich, smokey flavor.
Italian food. Plants from around the world.
As Europeans immigrated to the United States, they brought with them the varieties of tomatoes (and other plants) they grew up with in their home communities, and here they have continued to evolve. Just as Russian and Italian cultures and climate created distinctive tomato types, the melting pot of America brought a whole range of European heirlooms together to create distinctly new varieties, like the famous and wildly popular Brandywine tomatoes which came into being in gardens in Ohio and Tennessee.

It isn't surprising to me that the Brandywines, and other homegrown heirlooms like the Mortgage Lifter varieties, are so popular here in the US. After all, they were created here, the product of our culture, just as different European and Asian cultures have created their own specific takes on tomatoes that reflect their different values, cooking styles, and ways of life. Heirloom varieties are more than simply a crop, they are the result of a long, dynamic partnership between plants and people that has been going on since agriculture began. Weedy grasses give up life in the wild to become wheat and corn, one little plant scientists know as Brassica oleraceae morphed into myriad forms gardeners call broccoli, cabbage, kohlrabi, Brussels sprouts, and cauliflower, and of course, tomatoes sailed around the world to form a perfect partnership with Italian pasta.
Corn, before it teamed up with humans
Unfortunately, many gardeners today have given up their part in this ancient collaboration, ceding their role in the on-going evolution of the plants in their gardens to corporate breeders. Corporation, as they tend to do, have set out to replacing the endlessly diverse, personal forms of heirloom varieties created by and for a local community with new varieties which are efficient, uniform, and score well with focus groups.

This story has been told many times, and many gardeners have turned to growing historic heirloom varieties in response. But that is only half the solution. We've worked hard to preserve what previous generations have created. Now it is time to bring back the very art of that creation itself.
Pollinating tomatoes
Some gardeners are beginning to do this. Heirloom tomatoes came into being when their were fewer people in the world and have huge, sprawling vines that don't fit well in today's small yards or patios. A few years ago, a some gardeners were looking for delicious, beautiful varieties for their small gardens, and decided to do something about it. They got on-line and created the Dwarf Tomato Project, working as a community to breed a new generation of delicious heirloom-style tomatoes for small spaces. I love that, and I want it to spread. It is time we took back our plants, started making varieties for us, created by our friends, in our community, adapted to our local climate, soil, and tastes. It is time we started creating new heirlooms.

Which brings me to the big news of today's post. The working title of my upcoming book for Timber Press is Creating New Heirlooms, and it is going be all about the concepts I just outlined in this post. I'm super excited about it, and hope you are too!

01 November 2011

Sciency Answers: The great fertilizer debate

Gary has a question:

Are organic fertilizers such as GardenTone and HollyTone really worthwhile using or is putting compost on your garden beds just as good?

Feeding soil versus feeding plants
Compost provides two things when you put it in your garden. A small amount of fertilizer for plants to take up, and a huge amount of food for all the earthworms, bacteria, fungi, and such in the soil. The fertilizer component is released slowly over time as the compost is degraded by soil life and taken up by plants to use to build leaves and flowers. The soil eating the rest of it improves the texture and structure of the soil making it better at holding water, nutrients, and allowing plant roots to grow through it more easily, so the same amount of fertility is utilized much more effectively.

Fertilizers, on the other hand, just provide nutrients for the plants. Because they are not tied up in the complex structures of compost, they are released quickly in higher concentrations to the plant roots. There really isn't much of a difference between organic and synthetic fertilizers here. The compounds the plant roots actually take up are absolutely identical in either case, and, depended how they are formulated, both synthetic and organic fertilizers will be released fairly quickly in high concentrations. Since both lack the bulky organic matter of compost or mulch, neither are going to do anything to improve soil structure and health in the long term.

More isn't always better
Fertilizers need to be used with caution. I grew up in a rural area where most people's "lawns" were really periodically mowed meadows, never fertilized or watered, and full of as many flowers (what the lawn care companies call "weeds") as actual grass. But we got a new neighbor who had lived in the city, who wanted a green, all grass lawn. They bought a bunch of fertilizer, and dumped it on. Their grass turned a vivid shade of green almost over night. And after the next rain storm, so did the drainage ditch all down the street and a good portion of our stream with a mass of algae spurred into growth by the fertilizer bonanza. Because fertilizers are quite concentrated and release their nutrients quickly, it is easy to over do it. You can harm you plants, but long before you do, you'll harm the more delicate life in the soil, and pollute your local ground water and wetlands as all the extra fertilizer leaches out of your soil.

The bottom line
In my own garden, I rely almost exclusively on compost and mulch to provide fertility. I do use more concentrated fertilizers, but only rarely in my container plantings, and very rarely in new beds that haven't yet been beefed up with enough compost for hungry plants like vegetables. In my ornamental beds, I don't even use compost, just regular mulching, because keeping fertility relatively low there keeps my plants a bit smaller and more compact so I don't have to stake them. When I do buy fertilizer, I frankly don't see much difference between synthetic and organic, so I go with price and convenience, which leads me to a slow-release synthetic fertilizer.

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