Growing plants can be a stressful job, especially when problems start to appear. And since you can’t ask a plant what’s wrong with it, it’s best to know about some of the most common potato problems and fixes.
Some of the top common problems when growing potatoes are that the plant may not be producing, that the plant itself or its leaves may be changing color, wilting, dying, growing spots, being attacked by bugs, or that it might just not be growing well.
But just knowing the source of your problems is not enough. You also need to know how to recognize them, and even more importantly — how to fix them. For all of that information and more, read on.
Potato Plant Not Producing Potatoes
One of the vaguest and most annoying potato growing issues is this one — having no product at all. There are many reasons why your potato plant may not be producing potatoes, and some of them can be easy to fix while some cannot.
The first mistake you could be making is forgetting to check how fertile the ground itself is. Not just because it might be completely ridden of nutrients needed for potatoes to grow properly, but also because you could be over fertilizing later on, thinking that the land is not good.
There is such a thing as too much of the good stuff. While fertilizers generally help, they can also be damaging in large quantities. The land should be moderately fertile and adjusted with a small amount of fertilizer.
If you put too much fertilizer, you could have a problem of beautiful, lush greenery but no actual potatoes. Everything needs to be in perfect balance for potatoes to grow. Besides this overly lush greenery, you can also spot some curled or deformed leaves if there is too much fertilizer.
Another big mistake is adding too much nitrogen during the blooming season, and this often results in a poor or non-existing yield.
If the fertilizer is lacking, you can expect to see the canopy yellow or dying. The leaves will look unhealthy as well, getting that pale color, and they’ll be a lot smaller as well.
The solution to this problem isn’t that simple. If you added too much fertilizer already, try to tone it down and see what happens. If you haven’t added enough fertilizer to the plant, try to add more, especially during the blooming season, and especially nitrogen.
In general, take the cues from your plants. In the beginning, greenery is favorable since it contains food that will later be stored in underground storages that will later become your potatoes. Too much fertilizer and the leaves will just continue to grow with no potatoes to be seen. If you notice this happening, reduce the amount of fertilizer you are applying.
Potato Plant Turning Yellow
If your potato plant is turning yellow, there could be several reasons for that. Here are some.
Diagnosis – Wilt
Wilt is the most common reason why your plants are turning yellow. Of course, there are two types of wilt, and you have to figure out which one you have on potatoes to know how to fix that problem.
For one, there’s the verticillium wilt, which primarily affects the leaves. Under its effect, the leaves change into yellow color, and they become weaker. The first place where you might notice the signs is the bottom of your plant since this disease travels upward. If the problem remains unmanaged, it will cover the entire plant.
This is why it’s important to check your plants frequently. If you do, you’ll notice the problem sooner and be able to save your yield. This infection is quite stubborn, and it won’t just go away. The problem is that it can survive well in cold weather — so cold won’t help you get rid of it — but the heat helps it spread. In either case, you have a tough infection on your hands.
The biggest issue with this disease is that it will prevent your plant from using water.
The other type of wilt you might be dealing with is fusarium wilt, which is similar to the former type. However, the yellowing will appear first in the veins of your leaves, and it will move from there into the stems. The hot weather makes this type of wilt worse, and it is persistent, just like the former type of wilt. It starts at the roots, though, so noticing it will be harder.
But, you can act as soon as you notice discoloration in the leaves.
Wilt, as mentioned, is stubborn, and it won’t just go away. However, you can start the management process by identifying which wilt you’re dealing with. Most of the time, you’ll have a problem with verticillium wilt.
To avoid it in the future, plant grass or cereals at the spot where the potatoes have been to remove it. Rotate these plants every year. You might be able to fix it with fungicides, but it’s best to ride it out and then rotate plants to remove it completely.
Potato Psyllids Diagnosis
This is a bug that attacks potatoes, but it’s quite small. It’s black with white parts, and it releases a chemical that makes the leaves of the potato plant turn yellow. The leaves might curl as well.
The damage will start at the edges of your leaves and travel all over your plant. Of course, you want to prevent this. But, even a small amount of nymphs of these bugs can create a disaster for your potatoes.
Potato Psyllids Remedy
Start by identifying that you really do have a problem with these bugs. Do this with traps that you can purchase at your local gardening store. Then, once you know that you have this problem, you can move on to treatment.
The treatment includes using certain chemicals that repel and kill these bugs. Follow the guidelines on these select pesticides and apply them properly. Remember to repeat the process when necessary.
Potato Plant Turning Brown
Browning of the plant and the leaves could happen because of various issues, but most of the time is a sign of an issue progressing. For one, it could be a sign of wilt — leaves turn brown after turning yellow. It can also be a sign of potato psyllids, again after the yellowing.
Diagnosis & Remedy
However, it can also be a sign of other issues:
- If there are white specks and the browning is on the edges, you have a problem with leafhoppers, which can be dealt with by using insecticides or covering the plants with covers.
- If there are webs under the leaves and browning came after yellowing, you probably have spider mites that you can get rid of by spraying the plants with water, using insecticides, or introducing their natural predators into the environment (although this is harder).
- If your leaves start yellowing, then browning, and you find tunnels in the stems, you have a problem with wireworms that live in the soil. Before planting, check if there are any wireworms in. If you find them, flood that patch of land and remove any plants that have been infested.
- If the browning is on the edges, but the stem turns dark and becomes slimy, you have a fungal issue called blackleg, which happens if the soil is not drained. This problem is a bit trickier because you will need to rotate the crops and drain the ground.
- Gradual browning after yellowing can happen because of a lack of water and hot weather. Use mulch to allow your plants to absorb water and water potatoes often.
Potato Plant Turning Black
One of the reasons your potato plant may be turning black, especially at the stems, is because of blackleg. There would also be some slime in the same area. Blackleg is a fungal disease that is particularly hard to get rid of.
It generally happens if the ground is not well-drained and plant tubers that are completely free of any disease. This is a good way to prevent this disease. However, you should also make sure that you rotate potato crops with other crops to minimize the chances of blackleg appearing.
Another possible cause is black scurf, which is signified by a black mass on the tubers of the potato plant. This is a fungal issue that will grow best when the ground is warm. The best way to deal with it is to remove any plant where you noticed this infection and make sure that no plants that you plant have this disease.
Potato Plant Dying
Your potato plant could be dying for several reasons.
For one, it could be too hot outside, which is not something you can affect. However, if you do everything properly when planting your potatoes, you should be alright. For instance, you should plant them in a good type of soil for them, water them enough, etc.
But even with all of this, your potatoes could still die, especially if the temperatures grow too high. If the weather was cloudy for some time, then the hot sun and the winds attacked your plants, this could be damaging for your plants.
Another common cause of potato plants dying is poor watering. This is not to say that you don’t water your potatoes, but that you may be watering them inconsistently.
For instance, if you allow the land to dry for a few days before overwatering. This is not healthy for the plants, especially so during the time of development. The watering should be consistent from the moment you plant the potatoes, to the moment the leaves turn yellow, and you know it’s almost time to harvest.
If you want to prevent your ground from drying but you can’t be sure that you’ll always water when necessary, use mulch on the soil and make it easier for yourself. It will keep the moisture in the ground.
A plant can die because of the wilt as well. Both types of wilt cause yellowing of the leaves, although the verticillium wilt is more common. If caught early, you can deal with it, but it usually happens if you don’t rotate crops enough. You’ll notice that the plant is yellowing during the blooming phase.
Potato Plant Falling Over
The first — and the most common — reason, why your potato plant might be falling over, is that it is ready for harvest. This is the final phase of the growth cycle. The first thing you’ll likely notice is some yellowing, but the falling over will inevitably happen too. Of course, this only goes if you are certain that the potatoes are ready to be harvested.
This will usually happen around 160 days after you’ve planted them, but it could be less depending on the variety of your plant and other elements.
If your plants are not mature yet, you may have a problem of overfertilizing, as mentioned. The heaviness makes the plant simply fall over. You can use sticks to support them. However, overfertilizing may not be the best idea.
Has it been a hot few days? Has it been too cold? Your potato plants may be falling over because of this. Plants, in general, are not good with extremes in weather and changes especially. Avoid planting potatoes too late, and find a good middle ground in seasons for your area.
As mentioned, not watering your plants properly can be the cause of potato plants dying, but also falling over. Water them just right to avoid any issues, whether from overwatering or underwatering.
Your potatoes could also be suffering from a disease like early blight, late blight, and various fungal diseases. They may have also been attacked by insects.
Diagnosis – Early Blight
Early blight is a disease that affects the potatoes in the earlier stages of the growth process. It’s recognizable by the brown spots that appear on leaves. It’s a fungal disease that is spread by wind or water.
As a result, you will likely get a poor yield of smaller potatoes, or you might not get any. Blight spreads quickly. During the winter, it survives by staying in the soil, and it can also be introduced into the ground with poor quality compost.
Diagnosis – Late Blight
Late blight is another form of blight that affects potatoes and other plants; only this one hits them at the later stages of the growth. It’s more serious, spreads more quickly, and it can make all of your produce inedible.
You’ll see big spots on the leaves as a sign of this issue. However, it can’t just be in the ground on its own — it needs potato tubers. So, don’t leave them in the ground and make sure that you remove any that remain.
Late blight and early blight are similar, so the ways to get rid of it and prevent it are quite similar as well. For one, the soil in which you will plant your potatoes should be drained to prevent any fungi from forming.
Next, the plants should be covered if the rain is falling for several consecutive days. The weeds should be pulled often too, and you should use a fungicide even before this fungus appears. Prevention is often the best cure.
The plants should be dry before you water them again, and you should water them in the middle of the day to allow any stray water on the leaves to dry before the night falls. The water shouldn’t get on the leaves.
If you’ve already got blight, remove the plants that are infected and burn them. Clean the tools you’ve used and only then use them on healthy plants again.
Can Potato Plants Handle Frost?
Potatoes are normally planted at a depth that ensures they remain protected through the frosty times during the winter. However, you can’t expect leaves or stems to survive — only the roots will.
Most people plant potatoes early in the spring, which makes for a longer growing season and possibly better results. It’s generally not a good idea to plant in heat or near the summer as the potatoes stop growing when the ground warms up too much. Frost is much better for potatoes, in the sense that they can recover from that and continue producing.
Cold, especially if it’s not that serious, is definitely not dangerous to potatoes. It may kill the leaves and other above-the-ground parts, but not the most important part. If your plants have just stemmed, you can protect them with mulch if you don’t want a sudden frost to kill them. Try covers as well, especially if you have leaves already.
Potato Leaves Turning Purple
You may be used to brown or yellow markings on your potato leaves — but purple? Is it possible?
In fact, it is. And the reason is quite simple — your plant is lacking phosphorus. Plants generally need it to grow properly and look healthy. The most common reasons why this happens is if the ground is cold or if the plants are younger.
Another common reason is that your plants may be high in anthocyanins, which is a pigment that occurs in plants that have undergone some disease or extreme changes in temperature.
This is not a big issue, but it should be dealt with. Supply your plants with phosphorus and protect them from stress.
Potato Leaves Spots
Potato plants often have spots on the leaves, and the causes vary from serious diseases to something harmless. Let’s take a look at what different types of spots on potato leaves mean.
Potato Leaves Yellow Spots
Yellow spots are usually one of the first signs of some form of a potato virus. They are symptoms of early blight, late blight, wilt diseases, etc. To determine which of these diseases it is, you have to check with a professional and note any other issues. For example, with the most common type of wilt, the yellowing will start at the bottom leaves.
Potato Plant Brown Spots
Brown spots are the most common result of late blight. The spots will be big, so you’ll notice them easily. For more information on how to fix late blight, see the “late blight how to fix” section above.
Another possible cause could be a fungus called Alternaria alternata, which thrives in warm temperatures and gets to the plants through wind or water. It’s quite similar to blight, and it spreads quickly. The spots will be smaller, though. You can get rid of it with fungicides, and just like with blight, you can prevent it if you rotate plants, find good seed, and water properly.
Potato Plant Black Spots
Black spots on potato leaves are often a sign of late stages of blight. However, it can also be a black spot fungus that attacks many plants. It prefers warmth, and it thrives in these conditions, being spread by wind and water.
It causes leaves to fall off in the end, even though the spots seem harmless initially. You can get a fungicide and treat your plants with them. You can also treat it with neem oil, but it’s best to stick to expert recommendations.
Potato Plant Has Holes in Leaves
The holes in leaves of potato plants come from flea beetles, which are tiny bugs that you’ll barely notice. These bugs will eat your plant leaves and create those small holes in the leaves of potatoes.
They will also lay eggs, which will turn into larvae, and they will feed on the tubers of potato plants. They are not hard to deal with. People used to pick them off the plants, but you can make it easier by spreading ashes around the plants. Make sure that the area is clean and remove any damage that the larvae have done to the tubers.
Potato Plant Bugs
Potato plants have many enemies when it comes to bugs. Here are some of them:
- Wireworms and white grubs are the insects that live underground, and they can damage the seeds. They are dangerous, and you should make sure that you use an insecticide.
- Colorado potato beetle is a common potato bug which feeds on the leaves of a potato. They can kill your plants and make for a poor yield if you leave them be, so treat them with insecticides (even though they quickly grow resistant to them) at the right time.
- Aphids arrive in swarms, and they remove the sap from the plant, which can be harmful to your plants. You can consider using an insecticide or fighting them with their own predators.
- Potato leafhopper is a small insect that also removes the sap from potato plants. Because they are green, they are easy to skip, but they can also cause brown spots. An insecticide should help you get rid of them.
Potato Plant Leaves Curling
Curling in potato leaves is caused by several issues.
For one, it might be that your plant is attacked by aphids, which are small insects living underneath the leaves. They will leave honeydew behind — which is how you’ll spot them — and they can cause serious damage to the plant. Remove them with a strong blast of water or an insecticide.
It could also be blackleg, which was covered above. You’ll notice black slime on the tubers as well if this is the case. Another reason could be a disease transmitted by leafhoppers, and it can be fought if you remove the plants that were affected and deal with leafhoppers.
Potato psyllids also cause curling. To control them, use traps.
Potato Plants Leggy
Your plant may be leggy because of the wind or if an animal has attacked them. They may even be too heavy for their own strength, so they fall over. Another cause of this symptom is a lack of warmth.
To avoid any further issues, use stalks on these plants since they could be affected by fungi or insects if left to droop. Prune them back as well. Avoid over-fertilizing.
Potato Plants Rotting
The most common reason why your potatoes may be rotting is that you water them too much. The ground shouldn’t be soggy — it should be mildly wet. Seeds could decompose because of too much water, and so could plants if fully grown.
Try to find a middle ground between overwatering and underwatering.
Potato Plant Has No Flowers
While it can seem scary that your potato plants are not blooming, this is not a real problem. In fact, you don’t need your potatoes to flower to get potatoes. Some potatoes bloom, and some don’t. If you believe that your potatoes should be ready for harvest, but there are no flowers yet, try to dig up one of the plants and see what the results are. But generally, harvest the potatoes after all of the leaves have gone yellow.
So, there you have it — the most common problems when growing potatoes and their fixes. Use these tips to solve them and have a healthy and plentiful yield. Remember to prepare well for growing tomatoes, since that could help you avoid many of these issues.
For example, do your research on the type of soil that works well with potatoes, how much watering they need, etc. Once you know all of this, you can start growing healthy potatoes. You can also consult with someone with more experience in growing potatoes. But if issues still happen — don’t worry, return to this list and find the most practical solutions for them.