Cutting Seed Potatoes before Planting is a common planting practice that will save seeds and produce more plants in your garden.
As the weather starts to warm a bit in the spring it’s time to plant your seed potatoes. No matter what garden zone you live in, you usually start planting potatoes without any frost protection about 2 weeks before your last frost date. (To learn what garden zone you live in check out this post)
Cutting seed potatoes is a pretty common practice for many gardeners. But cutting seed potatoes before planting comes with a few drawbacks along with its many advantages.
If you are looking for a quick answer to your cutting seed potatoes questions and how to cut seed potatoes then watch the video I filmed above as part of my 5 minute Friday video series. If you want more details on cutting seed potatoes then read on!!
If you look at a seed potato you will see that each potato contains many “eye’s”. The small dimples you see on the surface of a potato are the eyes. As a seed potato gets ready to plant it will start to “chit” or sprout from those eyes. Those sprouts are what will eventually become the potato plant. And really each plant only needs 3 or 4 of those sprouts to establish and be productive.
So when you have a larger seed potato like this one in the photo above, it may have 15 or more sprouts. It is possible to cut this seed potato into 2 or even 3 pieces, dividing the sprouts between each chunk. Each of the pieces will then sprout, grow and become its own potato plant.
It is important to know how to cut your seed potatoes. When cutting seed potatoes I like to try and keep the pieces big and chunky. I also like to be sure that each piece has at least 4 or more eyes left on it after cutting. So most often I only cut the seed potato into 2 pieces. A particularly large seed potato may get cut into 3 pieces. There are a few folks out there that will disagree with this and say you can cut the seed potato into much smaller pieces with only 2 eyes. But I feel like you give the potato plant the best chance for success with chunky pieces with at least 4 eyes.
To cut your seed potatoes simply use a sharp knife, select a line that will give each piece at least 4 eyes and cut off a big chunk! Be careful to not cut through any of the eyes as this will destroy the future sprout. It’s that simple, suddenly 1 seed potato becomes 2 or 3 allowing for more potato plants from less seed. After cutting seed potato I like to have a piece that is at least 2 or 3 inches long and wide.
If you live in an area where there are soil born viral or bacterial diseases that affect plants in the Solanaceae family (Potatoes, Tomatoes, Peppers & Egg Plants). Then you might want to reconsider cutting your seed potatoes. Many garden experts recommend against cutting seed potatoes if you have these types of diseases in your garden. The idea is by cutting your seed potatoes you open them up to more vulnerability to soil born problems.
I have personally never had any problems with diseases on my potatoes that have been caused by cutting the seeds. But there is that possibility. So if you have had potato disease problems in your garden in the past then please skip cutting your seed potatoes. Also, keep your garden clean, any time you have diseased plants in your garden pull them out and dispose of them in the garbage. Do not put them in your compost bin. Practicing good crop rotation will also help keep disease problems down in your backyard garden.
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How Long Will Cut Seed Potatoes Last Before Planting?
Cutting seed potatoes before planting is a common practice that allows gardeners to get more plants from each potato. However, cutting into the potato also exposes more surface area to disease and rot. So how long can you store cut seed pieces before the quality deteriorates?
Proper handling and curing of cut seed potatoes can extend their shelf life. But in general, freshly cut seed tubers should be planted as soon as possible ideally within 1-2 days. With optimum storage conditions cut seed can last 4-6 weeks. However, germination rates and plant vigor will slowly decline over time.
Why Cut Seed Potatoes?
Cutting large seed tubers into smaller pieces saves money and resources. Each chunk containing at least one “eye” can sprout into a new plant. So from one large potato you can get 2-3 new seed pieces. This exponentially increases the number of plants from a fixed amount of seed tubers.
Cutting also creates uniformly sized pieces that will sprout and grow at the same rate. The downside is that slicing through the protective skin exposes more surface area to rot and infection. Proper post-cut handling reduces disease risks.
Curing Newly Cut Seed Pieces
Freshly cut seed potatoes need time to heal and “cure” before planting. Allowing cut surfaces to dry and callus over reduces the chance of decay. Ideal curing time is 1-2 weeks but 5-7 days may suffice for already sprouted tubers.
Cure cut seed for 7-14 days at 38-40°F and 85-95% humidity. Good airflow prevents CO2 buildup. After curing, cut seed can be stored up to 4 weeks before planting if handled properly.
Maximizing Cut Seed Viability
To maximize shelf life, handle cut seed potatoes with care. Bruising caused by rough handling can lead to rotting. Tips for keeping cut seed in good shape include:
- Store in shallow trays no more than 6 inches deep
- Avoid dropping seed pieces or throwing them around
- Transport gently to prevent knocking pieces together
- Keep cool (38-50°F) but allow 2 days to warm up before planting
- Maintain humidity around 85-95% to prevent drying
- Apply seed treatment to protect from disease
- Allow seed to warm gradually before removing from storage
With careful handling, cut seed can remain viable for 4-6 weeks when stored properly. Allowing pieces to warm for 2 days before planting also helps minimize shock. But after 6-8 weeks, chances of rot and weak sprouting increase substantially.
Ideally, cut seed just 1-2 weeks prior to planting day for best results.
Signs of Trouble
Watch for these warning signs of issues with cut seed potatoes in storage:
- Shriveling or wrinkling indicates drying out
- Soft, wet molding spots signify rot setting in
- Weak sprouts mean seed is aging and losing viability
- Greening of cut surfaces signals light exposure
- Stuck together seed pieces show inadequate airflow
If you notice these problems, isolate and discard affected tubers. Recut and cure a new batch of seed potatoes to replace them. Letting diseased seed go into the ground will compromise your crop.
Key Takeaways
Follow these guidelines to maximize cut seed potato viability:
- Cure 1-2 weeks after cutting before planting
- Handle gently to avoid bruising
- Maintain proper temperature and humidity
- Allow seed to warm for 2 days before planting
- Watch for signs of rot like shriveling or mold
- Discard severely damaged pieces
- Plant within 1-2 months for best viability
Proper curing, gentle handling, and avoiding old seed will go a long way towards preventing disease issues. But planting cut seed potatoes as soon as possible, within 1-2 days ideally, gives the best odds of getting a robust harvest.
Curing Cut Seeds Before Planting
One way to combat the disease issue is to let your seed potatoes cure for a few days after cutting and before planting. To cure them you simply need to let the cut potatoes sit in an airy, dry place that is out of the sun for 2 or 3 days. The cut side of the potato will dry and harden and get a leathery texture. This “hardens” up the cut side of the potato and helps keep soil born diseases out of the potato plant.
How To Cut Seed Potatoes
FAQ
How long can seed potatoes be cut before planting?
It’s the integrity of the seed potato which matters later on. Usually two days is plenty of time to let your cut potatoes scab over.Jun 11, 2022
Where to store seed potatoes after cutting?
Typically, cut seed held more than a few days should be kept at 50-55F and high humidity with good air movement (see “Storage” at this site) to promote suberizing and healing.
How do I tell if my seed potatoes are bad?
Potatoes are bad if they’ve gone squishy (they should feel firm to the touch), have bad bruises, the flesh has turned green, are badly sprouted and shrunken, or smell bad.
How long do cut seed potatoes last?
Follow those handling guidelines and cut seed potatoes can last 4-6 weeks in proper storage. Gradually warming the seed for planting 2 days ahead helps too. However, cut seed viability declines over time. After 6-8 weeks, chances of rot and weak sprouting go up. I try to avoid cutting seed more than 1 month before planting if possible.
How long do potato seeds last?
You can store the cut seeds for nearly 10 days. It would be better for you to plant the cut seeds after 3 to 5 days to get better performance. On the other hand, if your potato seed comes with non-sprout, you can wait 3 to 4 weeks for cutting before planting. It is also a standard time which you can follow.
How long can you store cut potatoes?
But you can store the cut seeds in a perfect space for a long time. On the contrary, you should not store the cut seed for a long-time because of losing the freshness, vitamins, and other things. According to my experience, keeping cut seed for 3-5 days is one of the best time range to get good quality potatoes.
Should you cut seed potatoes?
One of the disadvantages of cutting seed potatoes when growing potatoes is knowing how long to wait after cutting the seed potatoes. Not drying the potatoes for a long enough time can allow pests and disease to enter the tuber, as this removes all of the protective skin on five of the six sides.
How long does it take to plant a potato after cutting?
After cutting your potato seed, you have to wait a maximum of 10 days and a minimum of 7 days for planting. Potatoes cutting seeds take nearly 10 days for the curing process. Though 10 days are standard to keep cut-seeds potatoes, it also depends on several factors such as humidity, airflow, seed quality, and so on.
How long does it take for seed potatoes to cure?
One way to combat the disease issue is to let your seed potatoes cure for a few days after cutting and before planting. To cure them you simply need to let the cut potatoes sit in an airy, dry place that is out of the sun for 2 or 3 days. The cut side of the potato will dry and harden and get a leathery texture.