Whether you grow potatoes in the ground or containers there are several options for when to harvest. Once you dig them up, enjoy your homegrown potatoes fresh from the garden or follow the tips to cure them for long-term storage.
If you are new to this, there is a handy beginner vegetable garden plan here.
Harvest Potatoes From the Garden
It’s all fun at potato harvesting time. You’ve grown your plants for weeks or months and now you get to see how many potatoes have formed underground and what size they are.
Use these tips to know when it is the right time to harvest and how to save your potatoes in storage for use in the coming months.
- When to Harvest Potatoes
- How to Dig Up Potatoes
- Curing Freshly-Harvested Potatoes
- Storage Tips
When to Harvest Potatoes
The best time to harvest homegrown potatoes depends on the variety you are growing and what you want.
- Do you want smaller, tender ‘new’ potatoes?
- Would you rather wait a few more months for bigger, thicker-skinned potatoes suitable for cold-room storage?
Two Types of Potatoes
Potato tubers (the part growing in the ground that we eat) can be harvested any time after their first buds or flowers appear. This is a sign that the tubers are indeed forming in the soil.
But, to get the best each variety has to offer, find out its best traits.
Some potatoes are bred for early harvests and others are better as mature potatoes. And some are fine both early and later.
- New Potatoes | Also called young or baby potatoes; first earlies and second earlies | Ready in 2-3 months
- Storage Potatoes | Also called mature or main crop potatoes | Ready in 2-5 months
New potatoes are thin-skinned and should be consumed within weeks of harvest as they do not store well. They are called ‘waxy’ or ‘smooth’ because of their low starch content, which is compensated by the creamy texture.
Examples: Red Bliss, Magic Molly (95-100 days), German Butterball (85 days), Red Pontiac (80 days)
Storage potatoes have thicker, protective skins beneficial to longer-term storage. Most of these are high in starch and fluffy inside after cooking. The younger tubers are also fine to eat: they just don’t store as well as the more mature ones.
Examples: Idaho, Russet, Purple Majesty, Yukon Gold (sometimes not great in storage)
If you are a big potato fan, you could grow several varieties and enjoy fresh potatoes for months.
If you are new to growing potatoes, find a good source for certified disease-free ‘seed potatoes’ (tubers you plant to grow more potatoes) available to you (in person or by mail) and pour over the catalogue. There are so many interesting varieties to try.
What is the ‘eye’ of a potato? Appearing as notches on the tuber, eyes are axillary buds that can grow branches and form new plants. Seed potatoes (the potatoes we use to grow new plants) must have eyes to successfully grow.
Signs Potatoes Are Ready
As we head into fall, most potatoes still growing in our gardens will be storage potatoes.
Harvesting these main crop potatoes requires two steps before they stored: digging up and curing.
As the cooler weather sets in, the potato plant’s foliage usually starts to yellow and brown and die off and that is a big hint that harvest time is near. This is not to be mistaken with potato plant diseases or disorders: die off is a gradual, natural process.
I’ve had some varieties stay green without ever dying back until frosts set in—and still provide nice, big potatoes, but generally the tops do wither and die in autumn.
If you know the expected number of days to maturity for your variety, that’s another useful piece of information for getting the timing right. This tells you how long from your planting date you should expect it to take for the plant to produce potatoes for harvesting.
When this foliage die-off phase starts, you can cut back the growth to (perhaps) prevent disease or leave it—but don’t pull those spuds out just yet.
Harvest Before Frosts
Fall harvest time is always a juggling act with the weather. Potatoes are okay with light frosts but you want them out of the ground before hard frosts set in.
However, it is best to wait at least two weeks from the onset of yellowing foliage if you can. During this time, the potatoes (tubers) toughen up (in a good way), making them much less susceptible to damage and rot.
But, if there’s a real risk of freezing (or flooding), pull them out.
That said, if the potatoes are deep enough in the soil, they may very well have the perfect storage conditions where frosts can’t touch them. Not that I’d suggest in-ground storage (it’s unpredictable and inaccessible in winter), but we always miss a few when harvesting and it’s a rite of passage to unexpectedly dig up some of last year’s potatoes during the next planting season.
How to Dig Up Potatoes
If you grow your potatoes in bags or containers like I do, you can tip the whole thing over and pull everything out. I do this on a piece of tarp on the ground or my potting table if the container is not too heavy.
Harvesting in-ground potatoes requires more care. Use a garden or spading fork and allow a wide girth, digging far around the plant and getting deep below the potatoes to minimize any chance of piercing the spuds. If some do get pierced, set them aside for dinners this week.
If your soil is loose or sandy, you may be able to pull the potatoes out of the ground simply by grabbing the base of the plant and lifting the whole thing up.
Curing Freshly-Harvested Potatoes
Here you are with a nice pile of freshly harvested potatoes and it’s time to prepare them for storage.
Curing, also called hardening off, allows the skin to further toughen up.
Potato Curing Steps
- Remove excess soil with a soft brush, careful not to damage skin.
- Keep potatoes spread apart in well-ventilated, fairly cool, dark place for 10 to 14 days. Do not expose them to light.
- Ideal temperature range is 50 to 65°F | 10 to 18°C with high humidity (90 percent) which helps prevent drying out.
Most of us do not have perfect conditions like this but just do the best you can and check them daily, discarding any that start to shrivel or rot.
How to Store Potatoes
The Problem with Green Potatoes
We store potatoes in darkness because light causes the skin to turn green from the chlorophyll just like many other plants do.
That green color alone is not a problem but those same conditions that trigger greening can also increase the concentration of glycoalkaloids, a combination of two toxins, which you do not want to eat in high concentrations. They are always present in lower concentrations.
The toxins tend to congregate in the peel which can be removed. Unless the inner potato is also green, it is safe to eat. A bitter taste also indicates levels are too high.
Short -Term Potato Storage
You probably already know from experience what does and does not work in your home.
Based on food waste statistics, it seems we’ve all tucked away bags of potatoes only to find green, shriveled, sprouted or disease-ridden messes some time later.
In average household conditions (60-70°F | 15-21°C) with moderate humidity (50%), kept in darkness, potatoes should do fine for a few weeks or possibly a few months.
Any potatoes nicked or damaged during the harvest (but otherwise fine) should be consumed first.
If a potato is starting to sprout, you can eat it, but do so soon before it becomes bitter tasting.
The rest should go in long-term storage (see below).
Long-Term Potato Storage
The old-fashioned storage method is to wrap the potatoes in newspapers and tuck them in a cardboard box in a cool basement or cold room.
Optimum conditions for longer term potato storage: 40°F | 5°C temperature in a humid, dark place.
Cold storage of potatoes lowers the respiration rate (good) and reduces the chance of sprouting or decay.
If you have room, the fridge is also a good option, wrapped in newspaper or cling wrap and protected from light.
They will sweeten in the fridge so always let them return to room temperature before cooking to have that starchy goodness we all love.
Other Long-Term Potato Storage Options
- Make fries or chips and freeze them. You could use a deep fryer or an air fryer.
- Can potatoes in jars using a pressure canner.
- Freeze or freeze dry mashed potatoes.
Potatoes | Solanum tuberosum
- Ideal growing temperature: 70°F / 20°C. Do not like heat beyond 85°F / 30°C.
- Herbaceous flowering perennial, usually grown as annual.
- Botanically, potatoes are tubers (a specialized stem) not a root vegetable.
- Same genus as tomatoes: belong to nightshade family.
- Propagation: fastest method is to plant tubers (use certified disease-free). Can also grow from seed.
- Flower colors: purple, pink, red, white, blue with yellow stamens.
- Tuber colors: light brown, red, blue, gold.
- How to Harvest and Store Homegrown Potatoes
Shop Online: Potato Grow Bags (Amazon)
Why We’ve Been Told Not to Use the Fridge For Potato Storage
High Heat Discoloration
The advice to avoid refrigerating potatoes originated from a specific issue in the commercial production of French fries and potato chips.
While potatoes last longest when kept cool, cool potatoes processed at high cooking temperatures turn dark brown or black due to their reduced sugars (converted starch), making them appear burnt (although they are not) and unsavory. This is obviously not desirable for mass-produced potato products.
The discoloring is not an issue when boiling or baking potatoes.
One workaround at home—if you’re making fries or chips—is to let refrigerated potatoes return to room temperature before cooking at high temperatures, also known as reconditioning. This avoids the unwanted color change and gets those sugars back to starch.
It’s kind of crazy to think how many potatoes have been left to spoil in kitchen cupboards all these years because of a guideline specifically for commercial producers. We could have been using our fridges or another cool storage area and avoided many tons of food waste.
There is more information on this topic in the podcast episode (see player, below).
~Melissa the Empress of Dirt ♛