Thursday, September 8, 2011

Potatoes don't sunbathe and tomatoes like dry feet

I've been gardening seriously for 12 years now, so I've made a lot of mistakes.  There are a few that stick in my mind like slug slime.  These are the mistakes, due to lack of knowledge, or experience, that cost me a whole crop of certain plants.

The first is concerning potatoes.  They are a little finicky once unearthed from their cozy abode in the ground.  Sun is their enemy.  If they are exposed to sunlight for too long, self protection mode sticks in, and they develop toxins, turning green and making themselves generally unpalatable.  I knew this in my head, but didn't think anything of allowing my potatoes to sun dry on my front porch after harvest one year.

Thank you Lord, for this lovely potato that looks like an egg/rock.  I love it.  Now, please find me an earthworm to cuddle.
My friend Lisa, a seasoned gardener, stopped by that day and told me I might want to cover them.  By then, it was too late, and most of them had turned green...even the red ones were green beneath the red.  I read up on it, and it's really not a great idea to eat lots of green potatoes.  Potatoes are in the nightshade family, and ones exposed to too much sunlight contain higher concentrations of solanine, a toxin that can disrupt the nervous system.  The occasional green bit of potato won't harm anyone, but an entire crop might do some damage, particularly to children, because their small body mass cannot tolerate toxins in amounts we larger adults can.

How to prevent this?  When I harvest my potatoes, I shake off as much dirt as possible, but do not wash them.  This prevents rot from setting in.  Somehow, the dry dirt that eventually surrounds the potatoes protects them and allows the skin to thicken.  Dry your potatoes in a cool place, spread out a beneath breathable cover, such as a board.  I usually dry mine in my lawnmower trailer and cover the trailer with some plywood, allowing cracks for air to get in.

Whenever I'm in the garage, I stir the potatoes a little, and am sure to keep the door to the garage shut until my potatoes are safely stored.  Whenever I find a rotton potato, I throw it out.  Potatoes that have been cut when harvesting can sometimes still keep, but I put them in a separate container, just in case.  Once the dirt has dried, I weed out all the seed potatoes.  These are the potatoes that measure 1-2 inches in diameter.  I save them in a paper sack for the following year.  I usually stick any green potatoes in with the seed potatoes, because they can grow normal potatoes next year.   The rest of the potatoes go in paper sacks too, tightly rolled shut, and placed on a shelf above the garage floor, so moisture cannot collect in them.  The potatoes keep until the following spring, when they decide it's time to grow, and begin to sprout.  

My healthy Roma tomatoes from this year.  Unfortunately, I have a 3 year old who loves to pluck them, and then "plant them" again in the soil so they can grow.  I have about 50 green tomatoes on my windowsill, currently.

So I learned my lesson the hard way with potatoes.  What's another lesson I learned?  Tomatoes hate wet feet.  This means that they should not be planted in consistently wet soil, no matter how tempting it may be to save on watering time.  Tomato plants that do not  have well drained soil will develop beautiful fruit, but just as they are ready to turn yellow, then red, rot sets in on the bottom of the fruit, and they are ruined.  I had this happen to a gigantic crop of 20 plants.  It was very sad, and I believe I cried.

This rot is called Late Blight because it happens late in the tomato's fruiting cycle.  It is caused by the same mold, Phytophthora infestans, that caused the Irish Potato Famine.  This mold can set in and grow quickly if tomato plants are crowded and cannot dry out fully before evening.  It can also happen if the tomatoes are in consistently wet and soggy soil and cool weather.  This is the mold's ideal place to live.

Thanks to for the specific details on this disease.  

How do you protect your tomato plants, you ask?  Simply be a good gardener, and obey what all the gardening books tell you to do.  Tomatoes should be planted in well drained soil in full to partial sun.  Choose a sunny, dry place in your yard where you'll remember to water them in the morning, and you're ready to go.  If you can't find this, tomatoes do really well in pots, provided they are watered regularly, and have rich, well drained soil, and if it's consistently too cold out where you live, maybe it's time for a green house.

Like potatoes, tomatos are another plant you need to be diligent with around harvest time.  When I notice fall weather beginning to set in, I start to debate about when to uproot my plants.  This is because if tomatoes are left out in lots of rain, near harvest time,  their skins tend to split.  Where I live in the Pacific Northwest, this is a pretty common occurrence.  I if you live in a place with a short growing season like me, you are usually stuck with lots of green tomatoes on the vine when the cool weather sets in.  This used to disappoint me hugely, until I discovered that the tomatoes would continue to do their ripening while sitting nice and dry on the vine...inside my garage.

How to do this:  Just before the weather turns fall-like, carefully dig your tomato from the round, removing  your tomato cage along with it.   Shake as much dirt from the roots as you can, then bring the entire plant into a cool dry place, like a garage.  Set it on a clean, dry, elevated surface, and watch your tomatoes ripen right through the end of fall!  If it begins to get too cold in your garage, you can even pluck the still green tomatoes, and allow them to ripen on a windowsill inside.

Hopefully, these few lessons I learned in a difficult way will prevent you from some of the loss that I had.  Happy gardening!


  1. Thanks for sharing. We are neighbors here in the PNW (I am near Eugene, Oregon) and I have been struggling a bit with potatoes. Saw your comments on Northwest Edible Life's FB page and followed you here. Nice to hear from a fellow web foot!

  2. thanks for taking the time to check in! I hope my mistakes and learning experiences help guide you toward success! You can follow my blog on facebook. Just look for "Life in the Slow Lane"


I love it when people comment! Thanks for taking the time to do so!