It’s time to dig up your tender, homegrown potatoes when the buds drop or the flowers that do bloom begin to fade. Another good indication is seeing unopened flower buds dropping from the plant. At this point, the leaves will still be green but some will begin fading to yellow.
You can harvest potatoes as soon as they reach the size you desire. Generally, “new” potatoes are ready approximately 60-90 days from planting, depending upon the weather and the potato variety. One sign that young potatoes are ready is the formation of flowers on the plants.
Regular potatoes are ready to harvest when the foliage begins to die back. (See each variety for days to maturity.) The tops of the plants need to have completely died before you begin harvesting.
First Earlies There will be no sizeable tubers until the plants have finished flowering, so it’s not worth even thinking of lifting them until then. Once the plants have finished flowering, try a test dig to see if they are of a useable size. Only harvest what you need for a couple of days at a time.
If you don’t harvest potatoes when the plant dies back, a couple things could happen. Most likely they will rot if the soil is wet, or they ‘ll die once the ground freezes. But if you live in a warm and dry enough climate, any tubers that survive over the winter will sprout again in the spring.
About 99% of all the potatoes you ‘ll ever eat have been grown to maturity, dug from the ground and then “cured” – stored for a period of 10 days to 2 weeks in a climate-controlled environment. Truly new potatoes are sold right after harvest, without any curing.
If all conditions are ideal, you may harvest about five to 10 potatoes per plant for your gardening efforts. Yields are based on both the care your give your plants during the growing season and the variety of potatoes you choose to grow.
When storage temperatures exceed 45 degrees, potatoes should keep for two to three months, but sprouting and shriveling may occur. “Planting sprouted, shriveled tubers the following spring is not recommended because of excess disease levels, particularly viruses,” Mosley said.
If the potatoes are still firm and the skin is not green, yes, then you may certainly eat them. When you harvest them, inspect them for diseased looking tubers. Though it is recommended to plant certified disease free tubers. Practice crop rotation and plant the potatoes in a different area than they were last year.
Harvest begins in early September and can run through most of October. Most of the potatoes are harvested in the last two weeks of September and the first two weeks of October. Some varieties will be harvested earlier than that, but they don’t account for much production.
Potato plants will fall over when the plants are mature and ready for harvest. Potato plants can also fall over if they are too tall due to over fertilization, especially with nitrogen. Temperature, watering, diseases, and pests can also cause your potato plants to fall over, possibly without producing any potatoes.
Potato plants don’t need watering when they are established. The earthing up process will significantly raise the level of the soil trapping in any moisture below. Also the roots of potato plants go down a reasonable depth, enough to find moisture in almost all conditions.
ANSWER: Don’t worry if your potato plants aren’t producing blooms. They contain a toxic level of solanine, a poisonous alkaloid that forms when parts of the potato plant are exposed to sunlight. Solanine is the reason parts of the potato tuber turn green when they are in contact with sunlight.
The plant could look large and healthy, but the potatoes themselves may only be small and immature. If you harvest your potatoes too early, you can miss out on a heavy crop, but if you wait too long, they could be damaged by frost. To pick the best time for digging potatoes, watch what’s happening with the foliage.
Prune judiciously or not at all if you prefer longer, vine-like foliage. If you live in a mild climate, some potato vines will grow year round and need continuous pruning. Trim back any foliage that has been killed back or damaged after the first frost, down to the soil line or one inch above it.