ALBERT PARSONS/FOR THE SUN
Mature potato beetles overwinter in the soil.
Like the potato farmers of our province, home gardeners are busy these days digging their potatoes for winter storage.
Potato beetle larvae have voracious appetites. (ALBERT PARSONS/FOR THE SUN)
Potatoes come in several colours: (clockwise from bottom) Yukon Gold, Russian Blue, Red Viking, White Russet Burbank. (ALBERT PARSONS/FOR THE SUN)
Some urban gardeners grow a few potatoes in large containers. (ALBERT PARSONS/FOR THE SUN)
This annual gardening task is best performed on a sunny warm day after a period of dry weather so that you are not working in the mud.
If the soil is relatively dry when the potatoes are dug, the tubers will come out of the ground with little soil clinging to them. What soil that is attached to the potatoes will easily brush off after the potatoes have lain in the sun for a little while.
I often dig a whole row so the potatoes are exposed to the sun while I dig the rest of the row. Then I collect the potatoes into a pail and dump them out on an old bedspread — located in an airy but shaded location — to dry.
The potatoes should not be exposed to sunshine for very long or they will sunburn. When this happens, they turn green and become unpalatable. As you dig, you might encounter some tubers that are green on the top because they have been exposed to the sun while they were growing.
The best way to prevent sunburn on potatoes is to hill the potatoes early in the season so that there is enough soil over the hills to prevent any tubers from poking through the soil surface and being sunburned. Tubers that have sunburn on only one side can be used, but the green parts will need to be cut off and discarded.
I usually separate these tubers and store them apart from the rest of the tubers. We use them first, along with any tubers that were damaged during the digging process.
To prevent potatoes from being speared by the digging fork, it is a good idea to shove the fork into the ground far enough away from the centre of the hill to avoid spearing any of the potatoes that grow in a "wreath" around the plant stems.
Potatoes can be as far as 25 centimetres from the centre of the hill, and after spearing a few, you will soon learn the appropriate place to insert the fork into the ground.
Once the first few potatoes are unearthed from a hill, the rest can be harvested damage-free by shoving the fork quite deeply and lifting the remaining potatoes up from underneath.
Most gardeners plant their potatoes in rows about 35 centimetres apart. This allows enough space for the plants to develop and also provides enough room for surrounding soil to be pulled toward each hill during the hilling process.
Potatoes can be planted in early May as it usually takes a couple of weeks for tops to emerge and even if the tops get nipped by a late spring frost, the plants will soon recover. They like consistent moisture and a rich, friable, deeply tilled soil, and lots of sunshine.
The biggest pest in the potato patch is the potato beetle. These hard-covered beetles are whitish-yellow with dark stripes and winter over in the soil — so it is a good idea not to grow your potatoes in the same spot each year.
Commercial growers use a separation of at least 200 metres between this year’s location and last year’s crop, which is impossible in a small urban garden. But try to get as much separation as possible.
The adult beetles do little damage to the tops but they do lay eggs, which hatch into pink/red larvae with black spots and heads. They quickly sleletonise the potato tops if allowed free rein. It is this new generation of potato beetles that causes serious damage.
Frequent inspection of the potato patch is a vital part of prevention. If the numbers are small, the adult beetles can be picked by hand before they lay their eggs, thus preventing an infestation.
During inspection of the plants, look on the undersides of the leaves for egg clusters — they are bright orange and easy to see — and pick off and destroy any leaves that have eggs on them. This might be all that is necessary to prevent further damage to the plants.
Once many egg clusters hatch, however, and pink larvae begin to feed on the potato tops, more drastic measures are usually called for. There are vegetable dusts available that will kill the insects.
Some people claim that a dusting of plain old flour or finely ground wheat bran on the plants — dampened first — will do the same thing, but I have never tried it. Supposedly the bug eats the flour/bran and it clogs up its gut and it dies.
Another environmentally friendly method is to grind dry tansy leaves and dust the plants with the resultant dust.
Pyrethrum-based garden dusts are relatively non-toxic and can be used as well — perhaps a spray made of ground up pyrethrum (painted daisy) leaves would work as well.
Foliar sprays must be re-applied after each rain/watering and the beetles can be active all season, so this is a war waged all growing season.
After you have planted your potatoes, hilled them, watered and weeded them, fought off the potato beetles, and finally, dug them, you can store the dried tubers in cardboard boxes in a cool dark place where the temperature remains above freezing but below 8 degrees C. Higher temperatures will cause premature sprouting.
If stored properly, your potatoes will last all winter. You will be reminded of your summer garden each time you retrieve a few tubers for supper during our long winter.
Albert Parsons is a consultant for garden design and landscaping who lives in Minnedosa.
Republished from the Brandon Sun print edition September 26, 2013