Growing winter potatoes is best done in a warm climate or in sheltered containers. This is simply because it can be difficult to dig them up if the ground is frozen hard. The potatoes will also suffer from frost if they are left in the ground during winter in a cold climate.
However, there is nothing to stop you from growing potatoes in a conservatory, greenhouse, or a room set up for growing plants within your home. For example, even if you live in a place where frost and snow are common in winter, you will simply need a greenhouse heater that switches on automatically to prevent the temperature dipping below freezing point.
When you are growing potatoes during the winter, it is important to remember that growth will slow down when the days are shorter and colder. Therefore you need to start them in the summer (August or early September) if you want to harvest at Christmas, or a little earlier for Thanksgiving in the northern US. It is a wonderful feeling to be able to serve your own new potatoes with the family dinner on these holidays!
What is chitting and is it necessary?
You will often see recommendations that you should leave potatoes in a dark, cool place and wait for them to begin to sprout (chitting) before you plant them. If you have time to do this, that’s great. You may see that some potatoes are failing to sprout and you can pick out the ones with the healthiest looking sprouts to plant. However, if you don’t have time for this, don’t worry about it. Most potatoes will grow just fine without chitting.
If using tub containers, you can put 3 plants into an 18 inch diameter container. Be sure that the containers are cleaned well with water and have drainage holes. Place a couple of inches of gravel at the bottom of the container to prevent waterlogging.
Then, for growing potatoes in the winter, place 3 inches of mulch, leaves or straw on top of the gravel. This will produce heat as it breaks down and help to keep the potatoes frost free.
Plant them in about 3 inches of compost and fertilize well. Continue to add more compost and fertilizer as the plants grow, so that you gradually fill the container. If you can find organic potato fertilizer, that is ideal. Manure is too strong and will burn the roots of the plants.
The plants will continue to grow after the container is full. Then they will flower and a few weeks later the tops will start to die off. At that time the potatoes are ready. If you leave them a couple more weeks, they will continue to grow bigger.
Good varieties are Maris Peer, Charlotte and many others. You can buy seed potatoes or (provided you are growing in containers) you can use organic potatoes from the grocery store or locally grown organic potatoes from a farmers’ market.
Do not plant bought potatoes that are not seed potatoes in the soil of your garden, however, because they can carry disease which will then stay in the soil and affect future crops. For the same reason, if you grow grocery store potatoes in containers, do not spread the compost on your garden after you are done growing winter potatoes.