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Growing Tomatoes

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For each of the last 15 years, I've grown between 50 and 100 tomato plants from seed, which gives me a year's supply of tomatoes, tomato juice, tomato sauce, and salsa. And plenty to give away, also!

In southeastern Kentucky, the "frost safe" date is May 10th. To grow tomatoes from seed, you should start them 6-12 weeks earlier than your local frost safe date. I remember to get started sometimes between the Super Bowl and the SEC basketball tournament.


Start your seeds in a very light soil medium, either a commercial starting mix or a homemade mixture of sphagnum moss and vermiculite. I add some anti-fungal agent to prevent mold. Mix it with just as much warm water as the soil will hold. I plant the seeds in leftover food containers, label the variety (there are four different kinds this year) and cover the tray with a loose baggie. Then place the trays in a warm area, like on top of the refrigerator. When they sprout, remove the plastic and place them in a window or under a plant light. Water when needed, then drain the excess.

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I built special shelves in my southern-facing windows for plants. Young tomatoes need as many hours of sunlight as you can give them. Some of these plants are peppers and marigolds.

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When the seedlings have four leaves, you can separate them into their own pots. I use 2- or 3-ounce plastic bathroom cups, with holes in the bottom made with an ice pick. Peat pots dry out too quickly. Use potting soil, or a homemade mix of topsoil and your seed-starting mix. If you use compost, make sure you're not bringing insects into the house. Carefully jiggle the roots apart. Handle the seedlings by the leaves, not the stems, and try to preserve the roots. Bury them up to their necks, so that more roots will sprout from the underground part of the stem.

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If you plant more than one variety, label each cup, or else you'll never know how many you have of each when planting time comes! The CHE here is to designate cherry tomatoes. Water them thoroughly immediately after potting and check the pots for drainage.

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There is never enough window space, so I have a couple of plant lights as well. They run 24 hours a day so I can rotate plant trays under them for 12 hours at a time.

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When the outside temperature is above 50 degrees, you can set plants outside in the sun. This can be a chore, carrying plants out in the morning and in at night, but eventually the weather will be warm enough to leave them out overnight. By the first of May, I figure out how many plants of each variety I will need. I sell the others, which pays for my planting supplies, and give quite a few away to family and friends.

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Get your garden plot ready before the frost safe date by tilling the soil, laying a plastic mulch (if you don't like to weed), and setting up a trellis. A trellis will keep the vines and fruit off the ground. I use whatever is available, of course, so this trellis is made of branches, broom sticks, pipes, and rebar. Tomatoes should be planted two feet apart in rows three feet apart. That seems like a lot of room, but you'll need every bit of it. Unless you kill the plants.

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A wise man once told me you should dig a ten-dollar hole for a one-dollar plant. I dig a deep wide hole for each tiny plant and fill the hole with compost. Then I push the plant out of its pot by pressing on the bottom and slip the plant into the compost, once again burying it up to its neck. You can use the pots again next year. Water thoroughly soon after you plant. Wipe your feet before you go inside.


Water your plants every week if you don't get a good soaking rain. It's astonishing how fast they grow once they're outside! Use some soft string and tie the vines loosely to the trellis as they grow. You can see yellow tomato blossoms in this picture if you look closely. A pint of liquid fertilizer per plant every week will do a world of good at this stage, especially if your soil isn't all that great. I mix up 15-20 gallons of fertilizer at a time for this garden.

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Before long, the vines will be huge and you'll see some green fruits. Since they are green, you won't see how very many there are. I don't need to use pesticides, but you should keep an eye out for symptoms, especially if you use heirloom seeds. Modern varieties are quite resistant to disease and pests. The border of marigolds keeps out nematodes. The only critters that are drawn to my tomatoes are turtles, which can be apprehended and redirected easily.


Eventually, you'll spy a tomato turning red. This is a glorious day in the garden! It happens in mid-July where I live; your mileage may vary. For the rest of the month, I have enough tomatoes for salads and sandwiches. Then in August, I have to take a five-gallon bucket out twice a day to relieve the straining plants of their burden. Grocery stores love to advertise "vine-ripened" tomatoes, but I finish ripening most of mine in a window. Otherwise, the weight would tear the plants down! I pick tomatoes that are orange or light red. Once they start to turn color, they won't grow any bigger. When they are all red, they are the most delicious thing you've ever eaten.


Through the month of August, I am up to my elbows in tomatoes. The ripest are in the refrigerator, the barely ripe are on the counter, and the ripening fruits are in the window. When a bushel or so are ripe enough at the same time, I peel, chop, cook, and can them. By the time I come up for air in September, I have a year's supply of tomato products, a kitchen spattered in tomato juice, and a garden that has settled down to producing just enough for salads and sandwiches until the end of October.

See also: A Dozen Pumpkins, Do-It-Yourself Molded Pumpkins, and Salsa Time!

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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Live Smarter
Working Nights Could Keep Your Body from Healing
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The world we know today relies on millions of people getting up at sundown to go put in a shift on the highway, at the factory, or in the hospital. But the human body was not designed for nocturnal living. Scientists writing in the journal Occupational & Environmental Medicine say working nights could even prevent our bodies from healing damaged DNA.

It’s not as though anybody’s arguing that working in the dark and sleeping during the day is good for us. Previous studies have linked night work and rotating shifts to increased risks for heart disease, diabetes, weight gain, and car accidents. In 2007, the World Health Organization declared night work “probably or possibly carcinogenic.”

So while we know that flipping our natural sleep/wake schedule on its head can be harmful, we don’t completely know why. Some scientists, including the authors of the current paper, think hormones have something to do with it. They’ve been exploring the physiological effects of shift work on the body for years.

For one previous study, they measured workers’ levels of 8-OH-dG, which is a chemical byproduct of the DNA repair process. (All day long, we bruise and ding our DNA. At night, it should fix itself.) They found that people who slept at night had higher levels of 8-OH-dG in their urine than day sleepers, which suggests that their bodies were healing more damage.

The researchers wondered if the differing 8-OH-dG levels could be somehow related to the hormone melatonin, which helps regulate our body clocks. They went back to the archived urine from the first study and identified 50 workers whose melatonin levels differed drastically between night-sleeping and day-sleeping days. They then tested those workers’ samples for 8-OH-dG.

The difference between the two sleeping periods was dramatic. During sleep on the day before working a night shift, workers produced only 20 percent as much 8-OH-dG as they did when sleeping at night.

"This likely reflects a reduced capacity to repair oxidative DNA damage due to insufficient levels of melatonin,” the authors write, “and may result in cells harbouring higher levels of DNA damage."

DNA damage is considered one of the most fundamental causes of cancer.

Lead author Parveen Bhatti says it’s possible that taking melatonin supplements could help, but it’s still too soon to tell. This was a very small study, the participants were all white, and the researchers didn't control for lifestyle-related variables like what the workers ate.

“In the meantime,” Bhatti told Mental Floss, “shift workers should remain vigilant about following current health guidelines, such as not smoking, eating a balanced diet and getting plenty of sleep and exercise.”