Potatoes are one of the home garden’s favorite staples and one of the easiest crops to grow, and store. Small new potatoes are ready to be harvested within 10 weeks, while large, mature potatoes might take 80-100 days. Let us take a look at some of the signs that will tell us how to know when to harvest potatoes.
You know it is time to harvest large, mature potatoes when the foliage dies back. However, potatoes can be harvested right after the flowers appeared on the stalk. The flowers are indicators that the potatoes have formed underneath the ground. After the flowers appeared, the potatoes can be harvested. They will be small but can be harvested and eaten if small potatoes are what you are looking for. For those who like big, mature potatoes, wait and harvest once the foliage flops down, starts to dry, and starts to die off. Harvest potatoes using a garden fork or a garden shovel digging about 12-18 inches back from the base of the potato plant. While most of the potatoes will be around the base of the plant, there might be runners that grow out and away from the base. Dig and turn the soil then take out the potatoes. Dig carefully to avoid skewering or slicing any of the potatoes as they will not be suitable for curing and storing after they have been damaged, but can be eaten after being harvested.
How do you know when to dig up potatoes?
For small potatoes, dig them up at the flowering stage or shortly after the flowers fall off of the stalk. For large, mature potatoes, they can be dug up when the foliage starts to dry and die off. There can still be some green foliage but when the majority of the foliage is dead it indicates the potatoes stopped growing and can now be dug out. For extended storage, you can leave the potatoes in the ground for up to two weeks after the foliage has completely died off for the skin to toughen up. Do not leave them in the ground for more than two weeks after the foliage has completely died off as the potatoes can then start to sprout or rot, depending on soil moisture and temperatures.
I like my potatoes medium to large. I also like to dig them up once I know they are ready and I need them for cooking. I simply dig out as much as I need for the cooling that day, and leave the rest to grow and mature more. I dig them all out when about 50% of the foliage is nearly dead. At that point, the foliage is not feeding the tubers anymore and the potatoes stopped growing. I dig them up, cure, and store them. As soon as I dig my potatoes out, I plant new ones for my fall garden.
TIP: I start sprouting smaller potatoes about 2-4 weeks before I intend to plant them. I simply get small potatoes at the store if I don’t have any of mine, and let them sit in a basket in the dark basement. For planting, I only buy the small potatoes from the store that already have the sign of sprouting, so I know they will grow well.
How to harvest potatoes from a grow bag
To harvest potatoes from a grow bag, simply turn the grow bag upside down on a tarp or wherever you are comfortable to spill the soil. Using hands in gloves turn the soil and look for the potatoes. Harvest them as you turn the soil and use them immediately or let them cure before storing them. The soil from the bag can be refreshed and used again.
TIP: I never throw away any old or spent soil as long as the soil is healthy and carries no viruses or anything harmful. I always refresh the old soil by mixing it with my homemade compost, leaf mold, aged manure, and this fertilizer and it is ready to be used again. Old soil is also a great large garden bed, or large container filler to put on the bottom.
A GOOD READ: Can you use old soil?
What do potato plants look like when ready to harvest?
To harvest small potatoes or baby potatoes, look for a plant that has blooming flowers or a plant with flowers freshly fallen off. For the larger, mature potatoes, the plants will have a yellow to brown color, and most of the stems and foliage will be withered. This is the sign that there are mature potatoes underneath the ground that are ready to be harvested.
I am always very happy to see my potato plants flowering as potato flowers are a sign of tubers being formed underneath the soil surface. After flowering, it does not take long to the harvest time to harvest mature potatoes.
How do you know when potatoes are done growing?
Potatoes are done growing when the foliage has flopped over and started yellowing and drying out. If in doubt, when the foliage is dead, it is a sure sign of potatoes being mature and not receiving any feed through photosynthesis at which point they are done growing.
Do you always itch like I do, when you see your potato plants flopping? When they flop, I get so excited and just want to dig them out to take a peek. And I do. I usually dig out the first plant at the beginning of the bed just to see how large the potatoes are this year. Every year is different. Sometimes the potatoes are great, and other times they are smaller than expected. But that feeling when you dig in and you see that first large potato, what a satisfaction! I then cook freshly dug potatoes the same day and enjoy the rewards of my hard work together with my family.
How long can you leave potatoes in the ground?
Potatoes can be left in the ground for about 2 weeks after the foliage has completely died off. The skin of the potatoes will be tougher and these will be more suitable for longer storage. Do not leave the potatoes in the ground for too long after the foliage has died off as they might rot, start to sprout, or become infested by pests and develop holes.
I do not like to leave my potatoes in the ground for too long. How could I? I itch for such a long time to dig in! I like to dig out my potatoes once the majority of the foliage is flopped and yellow. I do not wait for the foliage to die all the way, because I like to replant potatoes as soon as I dig the first harvest up. I then plant my second potato crop which I harvest around the first frost. I use frost covers like this one if I need to keep the potatoes in the ground longer and the danger of the first light frost is upon us.
A GOOD READ: When and how to plant potatoes
What happens if you leave a potato in the ground too long?
If you do not harvest potatoes in time, depending on the moisture of the soil and temperature, the potatoes underneath the ground might start to sprout, rot, or get infested by pests. Wireworm holes or dry core holes might appear in the potato tubers, these potatoes are no longer suitable for longer storage and will go bad. Other pests like flea beetle, and potato tuber moths, might find their way into the tubers and cause damage. It is important to get the potatoes out no longer than two weeks after the foliage has died off.
Will potatoes regrow if left in the ground?
If potatoes are left in the ground in a non-freezing, mild climate, they will continue to grow but crowd each other and produce small entangled tubers. They might also rot and get infested by pests. The harvest will be full of small or infested tubers. For best production and to maximize the harvest, dig the potatoes out and replant them.
Best time to start a fall garden
