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At first thought, potatoes don’t seem like a very exciting crop to grow in your garden. These tubers are often thought of as bland, nutritionless roots that need loads of butter to taste good. But this couldn’t be farther from the truth: The humble potato is simple to grow, surprisingly flavorful, and provides abundant yields of nourishing roots that you can store all winter long.
However, there are a few common mistakes made by beginner potato gardeners that can severely reduce your yields. Improper planting, too much or too little irrigation, or forgetting to “hill up” could put all your potato growing efforts to waste. Fortunately, with a little bit of pre-planning and research, these errors are easily avoidable.
If you want to grow an abundance of tubers for summer potato salads, crispy morning hash browns, and cozy holiday mashed potatoes, avoid these 11 common potato-growing mistakes.
Planting Potatoes Without Eyes
Forgetting to check seed potatoes for “eyes” is the most common beginner gardener mistake. Potato eyes are the buds on the potato skin where sprouts emerge. You may have noticed them if you’ve ever had potatoes accidentally sprout in your pantry. The eyes look like dimples or little nubs, and they are arguably the most important part of the seed potato.
Seed potatoes are technically clones of a mother potato plant. When planted, they grow into new potato plants that produce an abundance of tubers. However, if your seed potatoes don’t have “eyes” or growing points, there is no way for them to sprout new leaves and stems.
Common Mistake:
When cutting seed potatoes into smaller chunks, beginners sometimes forget to leave enough buds on each block of seed potato. When these seed potato chunks are planted, they don’t sprout and end up rotting in the ground.
Another common mistake is accidentally bumping, damaging, or removing potato sprouts before planting.
How to Avoid It:
Check that every seed potato, or seed potato chunk, has at least 2-3 eyes per plant. Eyes that have already sprouted (whether through “chitting” or being exposed to light in your kitchen) should be handled carefully so the sprouts aren’t disturbed.
When planting the seed potatoes in the spring, be sure that the eyes or sprouts are facing upwards so they can grow stems and leaves up toward the sunlight.
Growing Store-Bought Potatoes
Most people don’t realize how chemical-laden potatoes are. When they are grown in industrial monocrops, a frightening volume of toxic chemicals, including carcinogens, pesticides like chlorpropham, and bee-harming sprays like imidacloprid. Yet another reason to grow your own spuds so you know exactly what’s going into them!
But the biggest problem for beginner gardeners arises when trying to plant potatoes they purchased from the grocery store. At a glance, these spuds look just like the more expensive “seed potatoes” purchased from a seed catalog.
But, when they are harvested, store-bought potatoes are also often treated with chemical sprout inhibitors so that they can be transported long distances and sit on grocery store shelves without sprouting. Gardeners who try to plant these potatoes will be woefully disappointed because the potato won’t be able to grow sprouts from its eyes like a standard seed potato.
Common Mistake:
Purchasing conventionally-grown potatoes from the grocery store and trying to plant them to grow new potato plants usually leads to crop failure due to sprout-inhibitors that were sprayed on the tubers.
How to Avoid It:
The best source for seed potato planting stock is a reputable garden store, nursery, or seed company. If you want to grow potatoes from grocery store spuds, be sure that you purchase USDA-certified organic potatoes. These have not been treated with chemical sprout inhibitors and will readily pre-sprout in your kitchen or greenhouse.
Planting Too Close
Potato plants require about 12” of space between plants and 24-26” of space between rows to grow to their fullest potential. Extra-large varieties may need up to 18” of space between plants, while fingerlings and smaller potatoes can be spaced as close as 8”.
When potatoes are planted too close, they can become overcrowded, stressed out, and more susceptible to disease.
Common Mistake:
Packing more seed potatoes into a smaller area will not necessarily increase yields. In fact, it can often result in smaller plants, smaller potatoes, and less overall vitality in the planting. Just like humans crammed into a subway, potatoes really don’t enjoy being overcrowded.
How to Avoid It:
Lay out a tape measure at the time of planting to ensure that seed potatoes are placed about 12” apart (depending on variety). If potatoes are moved during hilling or emerge too close together for whatever reason, thin out the less vigorous plants to allow the larger plants to thrive.
Failing to Hill Potatoes
We all know that potatoes prefer to be underground. These tubers are technically enlarged or thickened portions of the plant’s rhizomes. The plant uses these swollen stems as a source of nutrient reserves deep in the soil.
As it photosynthesizes, it funnels its extra minerals, water, and energy down to the root zone. This is why tubers are so starchy, tasty, and filling.
However, problems arise when potato tubers are exposed to sunlight above the ground. Like many of their wild relatives in the nightshade family, potatoes can accumulate a poisonous compound called solanine when they are exposed to light.
This is why you never see green-skin potatoes sold in stores. It is also why potatoes are not eaten raw. Potatoes are vegetables that grow best in the shade, and should be stored that way too!
Keeping potatoes buried and away from sunlight ensures that they are 100% safe foods without harmful levels of solanine. Potato tubers want to develop in complete darkness, so mounding soil on top of the plants (“hilling”) is a must.
Common Mistake:
If you forget to “hill up” potatoes as they grow, you may notice tubers popping out of the ground and emerging above the soil surface. Beginner gardeners often see potato foliage growing abundantly and forget to check that the base of the plant is thoroughly covered.
How to Avoid It:
Potato hilling is simply using a shovel, rake, or your hands to mound soil on top of potato hills. It’s usually best to do the first hilling when the foliage is 6-8” tall. These initial mounds of soil can be up to 4” up the plant’s base in a broad, widened hill shape.
Repeat the hilling process with an additional 2-4” of soil every few weeks until your potato mounds are 10-12” tall. You can also mulch with chopped leaves or straw to keep the soil cool, out-compete weeds, and prevent the greening of the potato skins.
Not Enough or Too Much Irrigation
In an ideal world, potatoes would prefer 1-2” of water per week through rainfall or irrigation. The soil should remain consistently moist and never completely dry out. Fluctuations in soil moisture can be problematic for yields as well as potato quality.
Not enough water or erratic watering can lead to wilted leaves and shriveled, dried-out potatoes. When the soil is dry from drought, potatoes are less likely to size up or produce an excess of tubers.
Remember that the potatoes we eat are the plant’s storage organ. If the plant isn’t getting enough water and energy to fuel its growth, it won’t have anything left to send down into below-ground storage.
On the other hand, too much water can cause premature rotting in the ground. I’ve seen potatoes literally disintegrate into mush when they are grown in waterlogged, swampy soil. Those tubers are definitely not appetizing!
Common Mistake:
Beginner gardeners sometimes get a bit overzealous with their watering habits, or they may plant potatoes and then ignore them altogether. Potato foliage can wilt from soil that is too dry, or it can look droopy from sitting in drenched mud. If you don’t stick your finger in the soil and check the moisture levels at least 6” down, you won’t know how much water your plants are really getting.
How to Avoid It:
Amend soil generously with compost or organic matter before planting. This will help ensure proper drainage while also improving the water holding capacity of the soil. Avoid planting potatoes in heavy clay, waterlogged soil.
Don’t let your potato beds dry out. Check the soil moisture at least once per week throughout the summer. Be sure to use drip irrigation or soaker hoses to water your potatoes during periods of drought. You can also use a chipped leaf or straw mulch to help maintain cool, consistently moist soil.
Not Enough or Too Much Fertility
Those huge baked-potato-worthy spuds need a lot of nutrients to form. Potatoes are moderate to heavy feeding crops that need ample fertility to yield. Without enough nitrogen, phosphorus, potassium, and micronutrients, potatoes may look yellow, pale, small, or not grow at all.
However, over-fertilized potatoes may produce way too much green foliage and very few actual potatoes. This doesn’t do much for us as gardeners hoping to harvest the nourishing below-ground tubers.
Key signs of too much nitrogen fertilizer, in particular, include deformed or rolled up leaves, aphid infestations, and disease issues.
Common Mistake:
If you forget to fertilize or amend your potatoes with organic matter, you may only yield small, underdeveloped tubers. On the flip side, over-fertilizing can lead to an excess of foliage and greenery with very few actual potatoes. Many gardeners forget to follow package instructions or they grow potatoes in depleted soils that haven’t been amended with mineral-rich organic matter.
How to Avoid It:
Mix a generous heap of compost or rotted manure into the soil before planting potatoes. Amend with an all-purpose organic granular fertilizer or feather meal at the time of planting. Each potato plant needs about ⅕ ounce of nitrogen for the season. This is often about a handful of granular 4-6-3 fertilizer per plant, or 1½ cup per 10 square feet of garden space.
Once the plants are established, provide a nice foliar spray of diluted fish fertilizer or another potassium-rich fertilizer every 3-4 weeks. Be sure to only fertilize in the morning or evening to avoid burning the leaves.
Too Much Weed Competition
A weedy garden isn’t good for any crop, but potatoes can be susceptible to competition in their early stages. Early emerging weeds within 1-2 weeks of planting potatoes can cause up to 50% yield reduction.
This is because weeds shade out young plants and steal their water and nutrients. If you don’t mulch or weed your potatoes, you may be disappointed by low vigor and a lack of tuber growth.
Common Mistake:
Forgetting to weed potatoes before they are established can lead to overgrown weeds that shade out or out-compete young potato plants. Inexperienced gardeners may accidentally rip out potato plants by pulling larger weeds without holding the potato plant roots in place. Hoeing too close to the plants can also damage the tubers or stems.
How to Avoid It:
Check your potato patch at least once a week to ensure that weeds aren’t taking over. Mulch generously with organic straw or chipped leaves to keep the weed pressure down.
When pulling larger weeds, hold the base of the potato plant with one hand and gently yank the weed with the other. This will ensure that you don’t inadvertently disturb your crop roots. If using a hoe to remove smaller weeds, be very careful not to scrape or cut the base of the potato plants.
Forgetting to Check for Pests
Potatoes are susceptible to a range of destructive pests, from Colorado potato beetles (CPB) to aphids to leafhoppers. CPB in particular causes more crop damage to potatoes than any other insect. These orange and black striped or spotted beetles can wipe out a crop in just a few nights if they get out of hand.
Similarly, aphids cause significant damage to potato leaves and can also spread potato diseases as they feed on the plants. Aphids often hide on the undersides of leaves and each female can produce up to 80 offspring per week. If you don’t check plants for signs of aphids, they can multiply extremely quickly.
Common Mistake:
Beginner gardeners often think you can just plant potatoes and forget about them. They may not know to “scout” their plants for pests before things get out of hand. This is the most important preventative measure for keeping potato plants safe from pests.
How to Avoid It:
Once or twice a week, whenever you check the soil moisture and hilling of your potato plants, quickly flip over the leaves to check the undersides for signs of Colorado potato beetle or aphid feeding. The most important time to scout is in the warmest months of summer.
Holes, rips, or “stripped” missing parts of leaves may indicate CPB damage. Ants or sugary sap on the leaves is a common sign of aphids.
If you see the slow-moving orange and black potato beetles in the garden, immediately pluck them off the plants and drown them in soapy water. Manual removal is the easiest way to prevent an infestation.
Harvesting Too Early or Too Late
Potatoes take 60 to 120 days to mature, depending on the variety. There are several time frames in which you can harvest potatoes.
“New” potatoes are young, tender spuds harvested in mid to late summer. These potatoes are smaller in size and have thin skins that are decadent when roasted or pan-fried, but very susceptible to damage. New potatoes are usually harvested for eating within a week or two, and they don’t cure or store very well.
Midseason potatoes are bred specifically for mid-summer harvests. They have some skin and size, but they aren’t fully developed for storage either.
Fully mature or storage ‘maincrop’ potatoes have the longest development window and are typically harvested in the fall around September through November. They have thicker skins and can be cured in the garden (after cutting back the leaves) or in a root cellar.
Pulling potatoes too early often means a disappointing harvest of small, undeveloped tubers. But harvesting too late can mean frost-damaged or rotten tubers that won’t store. Finding the perfect harvest window takes a little bit of attention and inspection.
Common Mistake:
It can be difficult even for experienced gardeners to know exactly when to harvest potatoes. If you aren’t tracking the days to maturity or actively going out to the garden to check the plants, there is no way of knowing when you should uproot your potatoes.
How to Avoid It:
When purchasing seed potatoes, take note of the estimated days to maturity and log the planting date in your calendar. Count forward the recommended days and set a reminder for when to check the harvest. Pull up one potato plant to inspect the tubers before harvesting the whole crop.
Flowering potatoes are another easy way to know when to harvest “new” spring potatoes. Once the downward-facing star-shaped flowers appear, check a few plants for size and harvest the amount you’d like to enjoy for summer treats.
For storage potatoes, wait until the foliage begins to yellow and die back in the fall. At this point, you can pull up a few plants to check the size of the tubers. Mow down or cut back the foliage a week or two before harvesting the rest (this lets them cure in the ground).
Damaging Potatoes During Harvest
Regardless of the time you harvest potatoes, their skins will always be sensitive when you first pull them out of the ground.
It’s very easy to scrape off the skin, accidentally stab the tubers with a digging fork, or otherwise damage the spuds with rough handling. These types of damage create channels for pathogens to enter the tuber, leading to more chances of premature rot before you get to enjoy the fruits of your labor.
The curing process is what makes potato skins thicken up for storage. Before curing, it’s important to treat potatoes as fragile babies so that they will properly store for the longest period possible.
Common Mistake:
Eager new gardeners often dig into potato harvests with a big digging fork and excited energy. But if you aren’t careful, you can easily stab tubers or scrape their skins while throwing them into tubs.
How to Avoid It:
At the time of harvest, put your broadfork or digging fork into the soil at least 6-8” from the base of the plant. You won’t know exactly where the tubers have spread out underground, but this gives you a little more buffer zone to avoid stabbing them.
Next, gently lift the soil upward and grasp the potato plant from the base to finish pulling it from the ground. As you remove the potatoes from the stem with your hands or harvest shears, be careful not to scrape off their skins.
Gently place them in a harvest container in a single layer and avoid rolling or shaking them around. For maximum storage and minimum damage, do not wash or wet newly harvested potatoes.
Forgetting to Cure Potatoes
Potatoes are the third most important staple crop in the world for a reason: they can last for up to 6 months in storage! But new growers often forget that storage doesn’t just happen straight out of the ground. There is a specific process for preparing potatoes to last through the winter.
Just like winter squash, potatoes need to be cured in order to thicken their skins and strengthen their flavors. Curing is the process of preparing potatoes for storage. It can be done in the garden or in a dark, warm area like a root cellar or pantry.
Common Mistake:
When you’re new to potato growing, it’s easy to just harvest the spuds and forget about curing them. Many gardeners pull the potato plants, wash off the tubers, and pile them in totes expecting that they will last all winter long. This can lead to rotting just a few weeks after harvest, which means no potatoes for scrumptious holiday meals or cozy winter soups.
How to Avoid It:
If you want them to last, don’t forget to prepare for the potato curing process! There are two main ways to cure potatoes:
- In the ground (before harvest): Mow back the foliage in late fall, stop irrigating, and allow potatoes to cure underground (ideally in dry weather) for 1-2 weeks before harvest. Do not clean or wash soil-cured potatoes after the harvest. Leave the soil intact and let them dry outdoors before moving to a root cellar or cooler for long-term storage.
- In a root cellar or pantry (after harvest): After pulling potatoes, place them in a dark, well-ventilated area around 50 or 60°F. An autumn garage is often a good place. Spread them out in crates or on newspapers for maximum airflow. Be sure that it stays dark so they don’t start turning green. After 1-2 weeks, the skins should be tough enough to pile in a container and move to long-term storage in your pantry or refrigerator.
Final Thoughts
Potatoes can be remarkably hands-off and easy to grow, but the best way to maximize your yields is simply to check them on a weekly basis.
If you want to avoid the most common beginner gardener pitfalls with potatoes, remember to:
- Plant seed potatoes with 2-3 eyes facing upward.
- Mulch potatoes with chipped leaves or straw.
- Mound up soil over potatoes at least once per month.
- Check soil moisture on a weekly basis.
- Be careful when harvesting, and prepare them for storage.
If you want to grow the best potatoes possible, avoid these common mistakes. As long as you plan well, and stick to the proper steps, you should have a plentiful and tasty potato harvest this season!
