How do I know when my potatoes are ready to harvest?
It helps to know what type of potatoes you are growing since different varieties mature at different rates. Early season varieties can mature in as little as 70 to 90 days whereas late season potatoes can take 120 days or more to reach their maximum potential.
As long as you are careful to break as few roots as possible, you can begin harvesting young potatoes once the plants have started to flower. For some varieties, this can be in as little as one month after planting.
Your main crop will be ready when the tops die back, but that doesn’t mean you have to race out to your garden and harvest them immediately. They can safely be left in the ground for several weeks after they have matured. However, they are susceptible to damage caused by insects - particularly grubs and wireworms – as well as voles, so it's a good idea to dig them up as soon as you can find some time in your busy schedule.
Ideally, a week or two before you are ready to harvest your main crop, you should cut back the stems to about two inches above the soil surface. This forces the tubers' skins to toughen, increasing their chances of storing well. However, almost no one I know actually does this, so if you skip this step, chances are your potatoes will make out fine in storage.
Potato tubers are usually pried out of the ground with a garden fork since it tends to inflict less overall damage than a shovel. Once out of the ground, the potatoes need to be brushed to remove surface soil and then cured in a sunny spot for the afternoon. Do not wash the potatoes or harvest them on a rainy day. Any moisture left on the potatoes will make them susceptible to mould and fungus and once one potato rots, the rest are in danger of following suit.
At the end of the day, sort through the tubers, setting aside any that are damaged or undersized. These are the potatoes you'll be eating first. The remainder need to be stored in paper bags, burlap sacks, cloth bags or any other container that allows air to circulate while blocking out light.
Place your potatoes in a cool, dark room for the winter, reserving the golf ball sized ones for next season’s seed potatoes.
If you have any questions or comments, please send them to me at vanessa@gardenmuse.ca.
Originally published in the Creston Valley Advance on September 10, 2009.
