How do you know if your potatoes are ready to harvest?
As straightforward as this subject may sound, there are different considerations you should be aware of before you begin harvesting.
How to grow potatoes
Before I begin this article – If you would like more information about growing your own potatoes, please read my article How to grow potatoes. This covers everything you need to know from planting, preparing seed, growing, harvesting and storage and more about this great vegetable.
When to harvest potatoes?
Although we know there are different varieties of potatoes, there are actually different “types” of potatoes which will ripen at different times of the year.
Different “varieties” of a plant means that there are different types of potatoes that have been grown and bred to genetically contain traits that may be needed or valuable to growers.
There are over 100 potato varieties that are well-known and commonly sold to fit a grower’s needs.
Some varieties are bred to be resistant to certain diseases that may be common in your area, while others are bred to mature at different times of the year.
This isn’t only dependent on the variety that you plant, but also depends on the obvious, when you plant it.
In this article, we will cover the main topic of harvesting potatoes, breaking it down into some main types of potatoes as well as what to look for as indicators for harvest readiness, and finally, we will briefly talk about storage considerations to have when getting ready to harvest your potatoes.
When to plant potatoes
When considering what variety of potatoes to plant, think about when you would ideally like to have a potato harvest.
There are potato varieties that are bred to do well planted earlier, in the colder weather and that will mature faster – these are known as early varieties.
Each of these varieties will have a different average for the time it takes for them to be ready, from the plant date to harvest date. On average, early season varieties will mature in around 75 to 90 days and are normally harvested in July when planted around February.
Some of these varieties may include Accent, Yukon Gold, Norland and Irish Cobbler, each slightly different in their general size, shape and texture. For more info about planting see: How to prepare your potatoes for planting
Mid season potatoes
There are also second earlies or mid season potatoes, these potatoes reach maturity in closer to 95-110 days and are normally planted later by a month or two as they don’t tend to handle the cold winter temperatures as well.
These are ready to be harvested between September or October, depending on the planting date.
A couple of varieties that you can choose from when considering mid-season potatoes include Gold Rush, Kennebec and Red Pontiac.
Finally, as the last harvest of the year and also generally considered to be a main crop, or even the main crop of potatoes are the late season potatoes.
These varieties mature in 120-135 days and are also normally the last ones to be planted if you are working on a garden schedule.
Late season potatoes will normally be harvest sometime between October and December, again depending on planting date.
Some varieties that work well as late season potatoes are Canela Russet, German Butterball and Purple Peruvian.
Varieties that work well as late season potatoes may also cross over as mid-season potatoes in many cases.
Preference for new potatoes or storage
Another difference in potatoes to consider when getting ready to harvest is what you want to use them for.
‘New potatoes’ are simply harvested earlier than when they are typically thought to be, when they will have very thin skin and be very small, normally used for cooking, stews and easy eating.
When to harvest new potatoes
When you see the flowers blooming on the top of the plant, that is your sign that indicates the potatoes will start forming soon. These potatoes can be harvested as ‘new potatoes’ within the next two to three weeks.
After they are harvested, they will need to be used within a couple of days or they will spoil since their skins are so thin.
When to harvest maincrop potatoes
‘Maincrop potatoes are harvested at the “normal” time, or in the middle or end of the autumn season, around November-time when the top of the plant, the stem and leaves, turn yellow and dry out.
Some growers will choose to harvest their potatoes as soon as the leaves begin to yellow and cut the tops off the tubers. The main reason for this may be that the potatoes are big and they dont want them to grow any more incase they crack or go hollow “Boast” in the middle.
Other growers make the decision to let the potatoes develop as long as possible and will harvest as soon as the stems and leaves are completely dried, brown and falling over.
This is when the potatoes that you pull up will be thicker skinned and will be able to be stored for a much longer time and retain their quality.
When thinking of a harvesting, consider the day that you go out to harvest seriously as this can greatly impact the storage quality of the potatoes.
Be sure to pick a dry day to harvest as harvesting potatoes and storing them when they are wet means they will rot.
As you harvest, have a bag or a bucket on hand to put them into, letting them come into contact with the sun’s rays as little as possible.
The sun will make them turn green and this indicates higher levels of a toxin (Solanine) the potatoes may contain, which will slightly poison and harm our digestive system.
This is a short video of us harvesting potatoes in good conditions in December using a small potato harvester. https://www.youtube.com/watch?v=MpJAJ_wHkxA
Finally, when getting ready to store the potatoes, consider the place that you will put them in.
It is best to move them there and keep them in the same spot with the same conditions until you are ready to use them.
The spot should be ventilated and cool, but not refrigerated and never below freezing. Refrigeration will cause the potato to convert the starch into sugars which turns the potato flesh black when frying. If a raw potato gets frozen it will turn to rotten mush when it thaws.
It is also best to keep them out of a lit area to prevent greening, so many people will store them underground or in a dark basement area.
Now that you have a good idea of potato varieties, harvesting dates and approximate times and storage, you should be ready to have a harvest that lasts you and your neighbors until the next season!