Growing potatoes can be a bit intimidating for beginner gardeners because it’s hard to tell how the tubers are doing underground. We have to depend on the greens to tell us of any problems with the plants.
So, what happens if potato plants start to grow abnormally tall?
Luckily, potato plants really can’t grow too tall. You only need to be concerned if your plants start to fall over. Even then, a falling potato plant doesn’t always mean your tubers are in trouble.
Read on to learn all about potato plant growth and what it might mean if your plants start to fall over. As a bonus, I’ll go over some staking methods to help keep your potato plants upright.
Can potato plants get too tall?
Potatoes have always been a fan favorite among compact and container gardeners due to their smaller plant sizes. The plants generally don’t get too tall and can be a good option for growing in buckets or other containers.
The average potato plant will grow to be about 24 inches tall, or 2 feet. Of course, this will vary between varieties.
Sometimes, potato plants can end up growing taller than many people were expecting. This isn’t necessarily a bad thing and there’s probably a simple explanation for it.
For starters, you may have just purchased a taller growing variety. Check with your potato seed provider to determine how tall your potato plants are expected to get.
Tall potato plants can also be indicative of tubers that are ready for harvest. Don’t be afraid to do a little dig to check on the size of the underground potatoes. You may find that your potatoes are quite large and ready to be dug up!
5 reasons potato plants fall over
Seeing any plant in the garden completely fall over is enough to send even the most confident gardeners into a panic. But don’t give up on your potatoes just yet! Here are some of the most common reasons potato plants will fall over.
1. Potatoes are mature
As they reach maturity, potato plants will begin to die back and may even fall over. As I mentioned earlier, a simple dig will tell you if your potatoes are ready for harvest.
When your potatoes reach maturity will depend on what variety you’re growing. In general, your potatoes will be ready for harvest in about 90-110 days from planting, or 3 to 4 months.
If you’re not sure when your potatoes will reach maturity, double-check with your seed provider. Here’s a chart with some common potato varieties and their days to maturity to further help you out.
| Days to Maturity for Potato Varieties | |
| Variety | Days to Maturity |
| Yukon Gold | 85-95 days |
| Elba | 85-95 days |
| Red Norland | 90-100 days |
| Satina | 65-80 days |
| Kennebec | 90-100 days |
2. Potatoes are leggy
Something to be careful of is that your plants are not getting leggy. Legginess happens when your plants don’t have adequate access to sunlight. To get as much light as they can, the plants will grow taller and stretch toward the light.
But this stretching causes weak stems that can easily fall over and even break. Not ideal for the health of your potatoes.
Potatoes need about 8 hours of sunlight a day for healthy plant growth. Anything less and you run the risk of leggy plants.
If you’re growing your potatoes in containers on a porch, make sure the plants aren’t getting shaded out by the porch roof or by your house. Potatoes aren’t really ideal indoor plants so if you notice them becoming leggy inside, then they’re trying to tell you that they want to be outside!
3. Too much foliage growth due to excess nitrogen
Sometimes, when potatoes are overfertilized, especially with nitrogen, they put more energy into growing greens instead of tubers. This can lead to excessively tall potato plants but smaller tubers.
Dig up some tubers to check on their size underground and adjust fertilization accordingly. If the potatoes seem pretty small, I would just stop fertilizing altogether to give the plant a chance to work on tuber production.
4. Over or underwatering
Improper watering can also cause your potato plants to fall over. Too little water and your plants will wilt and ultimately die unless they get rehydrated.
Too much water and the roots of the plants will become waterlogged and won’t be able to transfer oxygen anymore. Without oxygen, you may notice yellowing leaves and your plants may start to fall over.
To ensure adequate watering for your potato plants, make sure to water them about once or twice a week. If you live in a wetter climate with more frequent rainfall, you may find that mother nature does all the work for you.
Those who live in drier conditions will need to pay closer attention and may even want to consider setting up some sort of irrigation system like a rain barrel or some sort of drip line.
If you’re ever unsure about the moisture level in your soil, don’t be afraid to reach down and feel it. The soil shouldn’t feel bone dry, but it shouldn’t feel completely saturated either. A good consistent moisture level is what you’re looking for.
5. Pest and disease pressure
Damage from pests and diseases may also cause your potato plants to fall over. Make sure to do some scouting to check for any insect damage so that you can quickly work to address the problem before it ruins your crop.
Common potato pests include potato beetles, flea beetles, and wireworms. You’ll know if you have a potato beetle or flea beetle problem because most of the foliage on your plants will be filled with holes if not totally gone. This loss of foliage is what will cause the plant to fall.
Wireworms are a little more tricky to diagnose as they don’t attack the foliage but will burrow into the actual tubers. When you dig up a potato, you will notice small holes where the wireworms have dug into the tuber.
Sometimes these holes will heal over, but make sure to cut into your potato and check for any worms that may still be inside. Wouldn’t want to eat those!
For diseases, potatoes are prone to a number of different blights and rots. For more information on potato rots, you can check out this article here. Potato blight will cause the foliage to turn black and ultimately die.
Blight is a disease that lives in the soil, so once it starts to show symptoms, it’s too late to treat your plants. You can only try to slow it down. That’s why your best bet is to grow blight-resistant varieties of potatoes like Kennebec or Belmonda.
Staking potatoes
Similar to tomatoes, potatoes can be staked or twined to help support them. For individual plants, you can either place tomato cages around them or stake them.
For any gardeners that like to grow long rows of potatoes, the Florida weave is probably the best staking option for your potatoes. This method supports several plants at once by holding them between pieces of twine that are attached to T-posts at either end of the row.
Takeaway
Hopefully, this article has given you some peace of mind about your tall potatoes. Remember, there’s nothing wrong with tall potato plants unless they start to fall over. Even then, falling may simply be a sign that it’s time to harvest the tubers.
Be on the lookout for any pest and disease pressure, make sure your plants are properly watered, and that they have adequate access to sunlight, as these things can negatively affect the health of your tubers.
When in doubt, don’t be afraid to get your hands in the dirt and dig up a potato or two. This will give you insight into how the tubers are doing underground and let you know what, if any, actions you need to take to help out your potatoes.
