There is no gardener on this green planet who could portray anything but admiration for the humble potato, but despite being one of the oldest vegetable crops known to humans (and the first recorded vegetable to be deliberately bred and hybridized) these boring old spuds still manage to get the best of even seasoned gardeners.
In this article, we’ll share our favorite ways to grow potatoes, debunk some common potato growing hacks, and teach you everything you need to know about how to grow potatoes from fork to fork.
What are Potatoes?
Potatoes are a member of the Solanaceae, or nightshade, family. This vast family of plants includes deadly nightshade, as well as many common garden vegetables like tomatoes, peppers and aubergines.
Solanum tuberosum is the descriptive name given to potatoes, which are perennial vegetables developing tuberous roots that grow repeatedly year after year. The starchy tubers are the vegetable part of the plant, developing underground from extensions of the previous year’s tubers.
Despite being an underground crop, potatoes give us signs that they are ready for harvest, including flowering with vibrant purple and yellow star-shaped blooms in summer and autumn.
Potato’s Natural Habitat
Potatoes are native to the Peruvian Andes, with over 4000 species of potato found growing wild in the region. There is evidence that the Incas were cultivating potatoes as early as 10,000 years ago and it wasn’t until the 1500s that Spanish colonizers brought potatoes back to Europe, and in turn, to North America.
In the wild, potatoes spread well and thrive in the warm, rainy climate of Peru and South America. The high rainfall on mountains means potatoes are able to grow and spread, but they typically yield smaller crops in the wild than in cultivation thanks to some tried and tested potato growing methods that have evolved over centuries.
How do Potatoes Grow?
Potatoes are the starchy tubers of Solanum tuberosum. They are the root part of these tropical plants, and grow well in almost all climates, with many varieties able to tolerate prolonged frosts.
Any grocery store potato will have ‘eyes’. The eyes are the small divots on the outer skin of potatoes and are where new shoots will appear.
As those green shoots begin to grow, they sprout roots along their stalk, and those roots grow into new tubers until the plant flowers and begins putting its energy into seed production.
Different Types of Potatoes
There are three types of potatoes you can grow throughout the US, and all have been bred to deliver maximum yields at different times of year:
- First early potatoes - are best planted in early spring, when the ground thaws from winter and the soil is moist, but not sodden. They will usually crop after around eight weeks.
- Second early potatoes - should be planted in mid-late spring and take longer to crop but produce larger potatoes, and more of them.
- Main crop potatoes - are the biggest crop of all, wanting to be planted anywhere from late spring to mid-summer provided the soil temperature is good.
The biggest advantage of main crop potatoes is that they store well in the ground, so from fall harvests, some plants can be left untouched for fresh potatoes right through to Christmas.
First Early Potatoes
1. Accent potato
Accent is a really easy first early potato to grow, and despite its small size, has a brilliant rounded flavor that works well when boiled and left to cool, for salads, or just slightly cooled for boiled new potatoes alongside a summer BBQ.
2. Red Duke of York potato
Red Duke of York is my all-time favorite new potato, growing much bigger than most first earlies, and working brilliantly for mash, or just boiled.
As well as being easy to grow, they seem to tolerate wetter soils and rarely suffer blight. Although, they don’t have any specific blight tolerance bred into them.
The best thing about Red Duke of York potatoes though is that they have bright red skins, which hold their color when cooked, so they look incredibly sliced up on a dinner plate.
3. Casablanca potato
Casablanca are easy to grow and usually crop before blight can do any damage to the tubers. Keep an eye on blight above ground and remove any diseased foliage before it spreads and it can affect later crops.
4. Sarpo Una potato
Sarpo are a wide group of potatoes, all with good blight resistance, and excellent flavor. They are known as robust croppers, and Sarpo Una is the earliest Sarpo potato you can grow.
5. Winston potato
Winston are beautifully waxy potatoes, which make perfect mashed potatoes in early summer. They don’t develop many tubers, but those that do grow are much larger than average new potatoes, making them easy to use quickly, and a perfect summer treat for impatient gardeners.
Second Early Potatoes
6. Charlotte potato
Charlotte are our favorite second early potatoes to grow here, with soft crumbly tubers that just cook perfectly, either roasted or baked.
Charlotte potatoes make perfect hasselback potatoes too, thanks to their gorgeous skins which crisp excellently into the oven with just a light rub of olive oil.
7. Vivaldi potato
Vivaldi are high performing second earlies, which can actually be left in the ground for bigger tubers and harvested alongside main crop potatoes later in the year.
For easy gardening, there is no more versatile potato than Vivaldi! The extended cropping period can cover anything from 90-120 days after planting, meaning you dig them up plants-by-plant for continuous harvests.
8. Maris Peer potato
Maris Peer are usually ready to harvest from 15 weeks after planting, making them slightly later than other second earlies, but with much sturdier flesh that holds up well to all types of cooking.
I love peeled Maris Peer potatoes boiled then simply tossed in butter and chives.
9. Kestrel potato
Kestrel potatoes have beautiful purple patches across their skins, which surround the eyes. They look incredible after harvesting and have loads of vitamins in their skins too, so can be mashed with the skins on for a rustic side dish.
Kestrel typically crops 15-17 weeks after planting and should be chitted as early as possible.
10. Jazzy Potato
Jazzy potatoes are great summer crops, harvesting 14 weeks after planting, so are a good early alternative to other second earlies that are more interchangeable for main crops.
Growing Jazzy can bridge a gap between first earlies and second earlies, keeping you in good supply of fresh potatoes right through the year.
Main Crop Potatoes
11. Desiree potato
Desiree potatoes were bred in Holland in 1962 for their sheer size. They make incredible fries thanks to their waxy flesh that holds moisture and causes them to crisp perfectly.
Their skins have an incredible texture too, which works well when roasted whole with the skins on, and they don’t lose their bright red tone after cooking either.
12. Maris Piper potato
Maris Piper are the most commonly sold potatoes in grocery stores around the world and work well as seed potatoes straight from the store. They have matt skins and waxy flesh which is perfect for roasting and fluffs up beautifully after briefly boiling to soften the flesh.
13. King Edward potato
King Edward Potatoes are the classic Christmas dinner potato, with strong waxy flesh that stores well provided you stop watering early enough.
Boil peeled King Edward Potatoes for five minutes, then toss them in a colander to fluff up the outside, then pop them in the oven in a tray of hot fat, butter or oil and they’ll crisp up for perfect Christmas roast potatoes.
14. Orla potato
Orla Potatoes are a blight-resistant salad potato that can be grown all year round as a first early, second early or main crop. If you’re confused by the different types of potatoes, Orla is a great option as it can be planted right through from February to late June.
As well as cropping reliably between 14-17 weeks of planting, they are very resistant to both early and late blight.
15. Sarpo Mira
Sarpo Mira is a gorgeous pink, late main crop potato, which can be planted into July, and harvested as late as December. If you’re trying to plan a garden for all-year-round harvests, you need to try Sarpo Mira as a reliable winter crop.
How to Grow Potatoes at Home
Growing potatoes at home should be top of every gardener’s priority list, every year. Once you know how to grow potatoes, you will never look back, so follow our comprehensive guide to growing potatoes below for everything you could ever need to know about growing potatoes at home:
What month do you start potatoes?
Knowing when to start potatoes is more complicated than it first appears, but only because there are three different categories of potatoes you can grow.
First early potatoes, second early potatoes and main crop potatoes all need different weather conditions, and soil temperatures and all take different times to crop.
First Early Potatoes
First early potatoes should be planted as early as possible in spring, ideally around four weeks before the last frost. So, aim to plant first early potatoes in February or March.
First earlies are typically frost hardy, but check each variety before planting, as some are tender crops and should only be planted in southern states.
The best guide for planting potatoes is actually soil temperature rather than the weather, and you can speed up the process by warming the soil with cloches and leaving them over potatoes until they sprout.
Second Early Potatoes
Second early potatoes grow best in warmer weather but can crop just as early as first earlies. The difference in the quality of harvest from planting slightly later is huge though, so make sure you plant second early potatoes in late spring, around March/April where possible.
Second early potatoes usually take 12-16 weeks from planting to harvest, so are great for mid-summer crops.
Main Crop Potatoes
Main crop potatoes should be started in late April or May, but will usually cope well if planted in June or July for late crops. They require warm soil, lots of water, and full sun, so the later you plant them, the happier they will be.
How to Start Potatoes
There are a few different ways to start potatoes, including chitting, and separating potato eyes. For experimenting with kids, planting individual eyes is great, but it will usually lead to a smaller crop, and risks infecting plants before they even start to grow.
I’ve not mistyped, so wipe that smirk off your face. Chitting is the act of starting potatoes before they hit the soil. Potatoes are packed with starch and carbohydrates which give them the energy to spring into life when they’re ready and, bizarrely, its darkness not light, that will trigger this reaction.
The desired result when chitting potatoes is to trigger the eyes to sprout and send up new shoots. If potatoes are left in bright conditions they will sprout with green growth and tend to flower sooner than non-chitted potatoes, which produce smaller crops.
Do you need to chit potatoes?
Chitting potatoes speeds up the time to harvest by about 7-14 days but is not necessary for a reliable crop. The big benefit of chitting potatoes is that it helps develop stronger shoots, which are said to develop better roots.
In our experience, chitting isn’t 100% necessary but costs nothing, so worth doing.
How to chit potatoes:
- Place your potatoes in an old egg box (or any container that will hold them upright).
- Choose the side with the most eyes to face upwards.
- Leave them in a shaded, dry place for around 2-3 weeks. Anywhere with indirect sunlight is fine.
- When thick shoots appear from each eye, you’re ready to plant your potatoes.
Potatoes chitted in full sun will produce short white sprouts from each eye. These are still viable, but they have less energy than shorter darker stems chitted in indirect light.
Potatoes chitted in darkness will produce long white shoots that search for the light. These shoots spread energy out, and are unlikely to give a good crop, but can be planted horizontally in a single row in good compost.
They will typically produce multiple plants along each stem and take longer to crop.
How to Plant Potatoes
There are a few ways to get potatoes to perform to their best, and following several weeks of arguing about this with my fellow allotment holders, I can honestly tell you that I’m no closer to saying what the best way to grow potatoes is.
Some gardeners swear by grass clippings, others religiously hill up with hay. Some gardeners dig fresh manure into the bottom of a trench to help warm the soil, while others rely solely on watering and crop rotation to give potatoes enough nutrients to survive rather than thrive.
Judging by this year’s potato crop on our allotments so far, each and every method works well, as long as you space potatoes properly and plant them in full sun.
Best Location for Potatoes
Potatoes need full sun, but benefit from some shade from the midday sun. On our veg plot, we tend to grow potatoes either behind the compost bins (see our review of the best compost bins here), which shade midday summer sun, or in a bed behind Jerusalem artichokes, which allow light through, but keep the highest summer heat away from the developing plants, and seem to slow down flowering.
Another tip for growing healthy potato plants is to make sure they are well ventilated. This is a combination of spacing, and airflow, so choose somewhere that’s not too hemmed in by hedges or fencing so the wind can float through your plants.
How far to space potatoes?
The most important factor in growing potatoes is spacing. Potatoes are spreading crops that need plenty of nutrients, and hate sharing. Growing too many potatoes in a single container will lead to few, or even no viable tubers.
So let’s look at how far apart to space potatoes, and how deep to plant potatoes to get a full crop.
How far apart to plant potatoes?
Potatoes should be planted at a minimum of 1ft apart. It sounds a lot, but each potato can develop up to 15 tubers in perfect conditions, and each of those tubers needs its own supply of nutrients to develop into the starchy root vegetable we know and love.
If you are planting potatoes in pots or containers, you can get away with two potatoes in a 1ft wide round container, or three potatoes in a 1ft wide square container.
You will get fewer potatoes, but better water retention, lack of weeds for competition, and ease of hilling up will provide more growing space through the season.
How deep to plant potatoes?
Like planting any bulbs or tubers, potatoes should be planted at three times their depth. A large seed potato from a main crop variety can measure 3-4” across, so should be planted 9-12” deep.
This might sound excessive, but it allows for proportional growth as new tubers develop from the stem as it grows out, and means the cultivated area of loose soil is larger for larger crops.
Best Soil for Potatoes
Choosing the best soil for potatoes is important, but there are so many different methods that it’s hard to choose just one. The most reliable soil mix for potatoes that we’ve found on our plot for the last couple of years is this:
- Rotted manure or compost (learn how to make compost here)
- Reasonable drainage
- Loose tilth
- Slightly acidic (5.0 – 7.0)
Manure and compost are basically interchangeable, and it’s possible to amend soil using grass clippings (you can also use grass clipping as mulch) which helps improve drainage and aeration, but on the whole, rotted manure is the most tried and tested soil additive for potatoes.
Manure tends to be slightly acidic too, which helps increase acidity for potatoes.
Best Containers for Potatoes
Potatoes grow better with space, so are happier in the ground or raised beds, but potatoes will still grow well in containers and bags provided the soil conditions and care routine is right.
How to plant potatoes in the ground
Potatoes grow well in the ground, but it’s important to make sure drainage is sufficient. Potatoes might like moisture, but if they are left sitting in damp clay soils they will either rot or stall, producing a disappointing crop at best.
To prepare your soil to plant potatoes directly in the ground:
- Dig a trench 1ft deep (or in the bottom of a pot)
- Add rotted manure* mixed with grass clippings to the base of the hole
- Mix compost and topsoil over that, so the trench is roughly 6” deep (three times the depth of a potato)
- Push chitted potatoes into the trench
- Cover with 2” of loose compost (or mix topsoil with grass clippings to loosen its structure)
- You should now have shallow trenches that contain your potatoes with loose mounds of soil on either side, and that’s it. Wait for them to grow, and hill up as they develop.
* If you don’t have access to rotted manure but have rabbits, rabbit pellets are by far the best soil additive for potatoes and don’t need rotting before use.
How to plant potatoes in raised beds
Potatoes planted in raised beds should be planted exactly as you would in the ground (follow the guide above), but can be planted up to a week earlier as raised beds thaw faster in spring, and the soil will be warm enough earlier in a raised bed than the soil below.
How to grow potatoes in a container
Growing potatoes in containers is a great way to make the most of small spaces, or even add space to existing veg plots. Potatoes grown in pots or containers need very little extra help.
They should be planted just as you would plant them in the ground, but be aware that containers need watering more frequently during the growing season as they don’t have the benefit of groundwater.
To plant potatoes in a pot or container:
- Add 3” to 4” of compost, rotted manure, and/or grass clippings to the bottom of the container (any mix will do)
- Push your chitted potato halfway into the mix, and cover with 6” of compost (or three times its depth)
- Water well, then wait for it to sprout
- For every 2” of growth, add enough compost to cover all but the top leaves (usually adding 2” per week)
How to grow potatoes in a bag
While potato row bags are fiddly, they are space-saving and for small gardens, make a great alternative to containers as they can simply be washed and stored when not in use.
The disadvantage of potato grow bags is that they don’t protect early potatoes against frost.
Best Potato Grow Bags
Tip: If you don’t have a potato grow bag, turn an old compost bag inside out, so the black plastic is facing out. Black plastic heats up faster and helps to warm the soil inside the bag faster than paler colors.
Hilling Up Potatoes
What is hilling up?
Hilling up potatoes means to pull soil back around potato plants as they grow. As you add more soil, the plant is encouraged to send out roots from its stem, and the earliest potatoes are shaded from light, meaning they develop whiter flesh and are less likely to have green spots when harvested.
How to hill up potatoes in containers
Hilling up potatoes in containers is easy, just plant potatoes low down in a pot with a few inches of soil to cover them, and as they grow new leaves, cover the stems up to the leaf tips.
Stems will root and form new tubers, while the leaves will continue growing. Doing this every week, or every two weeks during spring and summer will produce much better potato crops.
Hilling up potatoes in the ground
Hilling up potatoes in the ground is all about preparation. Start by following our instructions above for planting potatoes in the ground, or raised beds, then:
- Every 2-3” of top growth should be covered as it grows, leaving just leaves and growing tips showing.
- Potatoes should be planted in a trench to begin with, so as they grow, pull in soil from the mound to the side of the trench.
- Pull in a few inches per week, until the trench becomes the mound, and the mount becomes the trench.
Caring for Potatoes
Potatoes are relatively easy to care for once they get going, but they need regular watering and hate competition from weeds. Below we’ll look at how to care for your growing potato plants.
While potatoes can cope with natural conditions, and most Northern climates provide enough rainwater for them to develop tubers, potatoes do like a lot of water if possible.
Potatoes should ideally be watered well once per week. Watering a little bit each day will waste water as it will evaporate from the surface. By watering thoroughly once per week you will soak the soil and water right down to the lowest tubers.
The moisture will last for a week in most conditions, but in severe droughts, watering twice per week is recommended.
If you are trying to save water, you can use rainwater from water butts, but also, potatoes will usually cope with natural conditions. But the more you water, the bigger the tubers will grow.
How to weed around potatoes
Weeding around potatoes needs a very particular tool called a Dutch hoe. Yes, you can weed by hand, but the risk of breaking stems is too high, and reaching in between rows of potato foliage can spread diseases like blight between rows.
The best way to weed between potatoes is to scrape weeds out using a Dutch hoe on warm days, then leave the weeds to dry out on the soil surface before removing them the following day.
The best fertilizer for potatoes
Potatoes can be grown in plain old garden soil if you don’t have access to compost, manure, or if you’re just gardening on a budget, but adding some liquid fertilizer is a good idea if you can get hold of any.
When to stop watering potatoes
When potatoes flower they are usually nearly ready for harvest, but there is still some growth left in the tubers below. As the flowers and leaves begin to wilt, reduce watering for two weeks, and then stop watering entirely. Leave the plants alone for 10-14 days after you stop watering to help the soil loosen back up.
The main reason to stop watering potatoes is to prevent rot during storage. Slightly drying the tubers for a couple of weeks in the ground forces them to send moisture to the foliage above as they try to continue flowering.
This reduces moisture in the potatoes themselves, which helps them to store for longer. The second bonus of stopping watering potatoes before harvest is that soil becomes easier to dig, and potatoes are easier to harvest.
When are potatoes ready for harvest?
While it’s possible to time potato harvest in weeks or months, the best way to know when to harvest potatoes is the signs on the plant. When potatoes begin to flower that’s a sign that they are almost ready to harvest, but leaving them in the ground can lead to better-storing potatoes.
This isn’t important for some varieties, but for many, it can be the difference between storing for a week and storing for two months. When potatoes have flowered, stop watering them (as above) and leave the leaves to wilt.
They will start looking drab and yellow, but this is ok, it’s just potatoes dying back. When the leaves are yellowing, it’s a sign that the potato tubers have dried out a little, and are ready to harvest and store for as long as possible.
When to harvest potatoes (by month)
Depending on the variety of potatoes you are growing (first early, second early, or main crop) harvesting times will differ, but as a rule of thumb, potatoes are ready to harvest 12-16 weeks after planting them.
Potatoes planted earlier in the year will take slightly longer as the warmer summer days are what trigger flowering, and help tubers develop healthy skins and lose their green flesh.
And just to make life easy for you, here’s our guide to planting and harvesting potatoes from earlier:
How to Harvest Potatoes
Harvesting potatoes is easy, but you’ll never get every last potato if you’re growing them in the ground. Don’t worry though, many potatoes are perennial crops, and by leaving a few tubers in the ground you might get lucky and have an earlier harvest next year.
To harvest potatoes in containers, or to harvest potatoes in potato grow bags, simply tip the contents out onto the floor, and sift through to find masses of tubers that can be eaten straight away.
To harvest potatoes in raised beds or in the ground, get a wide tined garden fork, and dig as carefully as possible through the soil, lifting and turning as you go.
If your soil is loose enough you can often lift the plant first, which can come up with tubers still attached. However, it’s still important to dig through the ground as there will inevitably be some tubers that have detached from the main plant.
Don’t worry if you stab a few tubers, they’ll still taste fine, but you won’t be able to store them – just clean them off and cook them within a couple of days.
How to Store Potatoes
Provided you’ve followed our guides for when to stop watering potatoes, and how to harvest potatoes, storing potatoes is simple. Just keep them away from the light.
Potatoes kept completely cool and dark will keep for months. Ok, they might start to wrinkle, but as long as they don’t develop green spots they are completely safe to eat.
One hack for storing potatoes for longer is to fill a box with dry play sand or dry sharp sand and bury your potatoes in it. Cover the box and keep it dry, and your potatoes should keep right through winter.
Potato Growing Hacks
As well as the age-old method of growing potatoes above, there are some hacks worth trying, as well as one that’s simply not worth the effort!
How to Plant Potatoes from Eyes
Potatoes technically just need their sprouting eyes to grow, so you can plant a whole row of potatoes from a single tuber by slicing it into sections with 1-2 eyes per cube.
Now, this is one of the most popular potato growing hacks on the internet, so don’t let me put you off, but there is one huge downside to this method of growing potatoes: it produces fewer potatoes.
As well as smaller crops, it also relies on having somewhere cool and dark to store your potatoes so they can callous over across the cuts for a few days, and following that there is still no guarantee that these tubers won’t simply rot in the ground when planted.
Leave potatoes in the ground for an easy harvest next year
Potatoes are perennial crops, and one of the few true perennials in the solanum family. Tomatoes can crop a second year if cut back and stored somewhere sunny, but are not naturally perennial, the same for Aubergines and peppers.
Potatoes are uniquely adapted thanks to their tuberous root systems which sprout with fresh leaves every year. While treating potatoes as a perennial crop might seem like it's saving time and effort next year, it does mean the following crop is growing on used compost, so will not develop as quickly.
Where to Plant Potatoes in a Crop Rotation
Crop rotation is something every gardener should practice. It’s a great way to get the most out of your compost, and maximize yields. Even in small gardens with containers to grow veg in, you can reuse potato compost for beans or peas the following year.
To improve soil quality and reduce pests, try growing cabbages one year, then potatoes in the same spot the next year. Cabbage and sweetcorn (or grains) help to reduce root-knot nematodes and Rhizoctonia, a fungus which can rot potatoes as they grow, and devastate harvests.
The best crop rotation for potatoes is:
Growing Potatoes from Grocery Store Potatoes
Do you really need seed potatoes? Well, yes and no. Seed potatoes are far more reliable than grocery store potatoes, which have often been stored in artificially cooled sheds.
Artificial cooling might make potatoes last longer but it tends to lead to leggy sprouts when potatoes are chitted and a smaller crop.
Having said that, for gardeners on a budget, grocery store potatoes are much, much cheaper than seed potatoes and will almost always grow new tubers if planted in mid-spring.
Just be aware that grocery store potatoes have been exposed to the light for some time, following a long time in darkness, and are hard to prepare.
Potato Pests and Diseases
Root knot nematodes
Root knot nematodes feed on the outer flesh of growing potato tubers. As the tubers develop, they grow lumpy blisters which are unsightly, but still edible.
The problem with root-knot nematodes is that once they are in the soil you need to wait at least three years before growing potatoes in the same spot again, and should avoid growing carrots or other root crops nearby too.
There are soil treating insecticides available to treat the problem but they are never 100% effective and do lasting damage to biodiversity in your soil (thus damaging soil health in general).
If you’ve recently converted a section of lawn into a potato patch you will more than likely have wireworm. Wireworms feed on grass roots and burrow right the way through the tubers. Their tunnels will harbor bacteria and appear as hollow black spots across potatoes.
As with most potato pests, the crop is still edible, provided the holes have dried up as the insects don’t live in the tubers. Simply slice and cook as normal.
The problem with wireworms is that they affect the overall vigor of potato plants, and will live in the soil for several years after grass or solanum crops have grown there.
Potato leafhoppers are small members of the cicada family (Cicadellidae) and present a serious danger to potato crops. Once established, they are difficult to get rid of, and small colonies can eat an entire plant’s foliage in a couple of days.
Worse still, if potato leafhoppers are found but have already reduced the foliage significantly, it will reduce your crop. The best way to manage these pests is to encourage birds into the garden as they are expert leafhopper hunters.
Colorado Potato Beetle
Potato beetles are common in the US, feeding on potato crops, tomatoes, aubergines and peppers in equal measure. Their red larvae feed on the underside of potato leaves and grow in striped beetles with an orange thorax.
The first signs of potato beetles are small clusters of orange-yellow eggs grouped underneath leaves. These eggs can be scraped off plants and disposed of, the larvae can be scraped away, or simply washed into the soil.
If the problem reoccurs or is causing severe damage, organic pesticides like neem oil are a great way to kill populations of pests on potato leaves.
Aphids are attracted to the new growth of potatoes early in the season and can hatch from the soil, particularly following cabbages and brassicas in a crop rotation. Aphids are simple to deal with on potatoes and rarely cause severe damage.
To remove aphids, wash them into the soil with a strong jet from a hose, or apply neem oil directly to the plant at dawn or dusk before most pollinators are active. This helps to prevent accidentally killing bees, ladybugs or wasps, who are more active in the morning and afternoon.
Early Blight (Alternaria solani)
Early blight is by far the most frustrating problem when growing potatoes and can stop a harvest before it even begins. To avoid blight, don’t grow potatoes in the same spot as tomatoes or other solanum crops, and keep them well ventilated.
Avoid watering the leaves of potatoes by watering directly at the roots. Blight is a fungal disease which kills off potato foliage in late spring and can travel down the plant to the roots causing young tubers to deform and develop dark sunken lesions.
Antifungal sprays can help reduce the spread of blight, but it is best to cut back any blighted stems and leaves and burn them when you spot them to prevent further infection.
Late Blight (Phytophthora infestans)
Late blight is typically more visible than early blight, with black stems that spore out as powdery dust when touched. Late blight spreads quickly and is hard to control, but usually happens in summer and autumn when potatoes are ready to harvest.
Before harvesting potatoes with late blight, cut back the stems and burn them, or bin them, then spray the soil with fungicide. Dig up your potatoes and then refrain from planting potatoes or tomatoes in the same spot next year.
Potato scab is caused by bacteria in the soil, namely; Streptomyces: S. scabies, S. acidiscabies, and S. turgidiscabies. In commercial potato fields, Scab is almost inevitable, but it is easy to manage at home.
Grow acid-loving crops with acidified soil (a pH of 4) to kill Scab. The symptoms of potato scab are dark crisp lesions which tend to form in clumps of circular brown spots that peel away from the rest of the potato skin.
If your harvest has signs of scab it is still edible but it’s best to peel tubers before cooking to remove the unpleasant texture.
Rhizoctonia (Canker / Black Scurf)
Black Scurf, or Rhizoctonia Canker are both identified by irregular black spots all over potatoes. They are fungal diseases that thrive in cool, wet soil.
Potatoes with canker do not store well and develop spongy, or corky dents after harvesting. Potatoes with canker can still be eaten, but the black spots should be removed.
To reduce the presence of these fungi, improve drainage, water less frequently, and grow cabbages, which help to reduce the presence of Rhizoctonia Canker in following crop rotations.
Fusarium Dry Rot
Dry rot is one of the few diseases that makes potatoes truly inedible. While there is no danger in eating potatoes with dry rot, the texture and flavor are awful.
When you cut a potato with dry rot the entire tuber can be filled with black hollow cracks. Fusarium is more prevalent in stored potatoes and happens as a result of storing damaged tubers.
If one tuber is damaged when it goes into storage it can spread the rot to other perfectly healthy tubers, ruining your harvest. To avoid dry rot in stored potatoes, never store damaged tubers.
Phytophthora erythroseptica (Pink Rot)
Pink Rot and Pythium Leak are soil-borne storage diseases which enter potatoes where the stems meet the eyes. During storage, the eyes of potatoes hold the disease, which spreads throughout the whole tuber quickly.
Pink rot then moves between tubers using the eyes as entrance points. When you cut open potatoes with Pink rot they first appear slightly pink, or off white, and within 30 seconds turn black as the pathogen oxidizes.
There are soil fungicides you can use on potato patches to prevent pink rot.
Colletotrichum coccodes (Potato Black Dot)
Black Dot, or Colletotrichum coccodes, is a fungal infection which spreads through spores, and insects between plants. The signs of Black Dot are small black spots on potato leaves, usually slightly smaller than blight, but which grow and spread quickly.
Black Dot can spread to potato tubers and cause the skin to detach from the potato in storage. If you notice black spots on potato leaves, it is always best to remove those leaves and burn them, whatever the cause.
Helminthosporium solani (Silver Scurf)
Silver Scurf, or Helminthosporium solani, affects potatoes that are intended for storage more than new potatoes or second earlies.
The first signs are dry silvery blemishes on potato skins at harvest, but during storage, it can cause potatoes to dry out excessively and eventually wither to inedible pebbles.
The only real damage to potatoes with silver scurf when eaten fresh from the ground is aesthetic though as it doesn’t affect the flavor or texture of freshly dug potatoes.
Growing Potatoes Frequently Asked Questions
Can you eat green potatoes?
Never eat green potatoes. Green potatoes have been exposed to the sun, either from inadequate hilling up or from exposure to the sun during storage.
Exposure to the sun causes the production of solanine, the toxin present in deadly nightshade.
How long do potatoes take to grow?
Potatoes are usually ready for harvest after about 90 days, but some new potato varieties are ready after just 60 days in the right conditions.
Main crop potatoes usually take around 120 days to harvest and can be left in the ground provided there are no signs of fungus or blight on the wilting top growth.
How late can you plant potatoes?
In mild climates, early July is still fine to plant potatoes, but they should only be started outdoors when the weather is still relatively cool. The safest last date for planting potatoes is mid-June.
Can you plant potatoes in winter?
Some potatoes can be grown in winter provided they are grown in full sun and protected from severe frosts. While there are frost hardy potatoes they won’t continue cropping if they are hit by prolonged frost as they will return to dormancy or rot.
Will potatoes come back every year?
Potatoes are perennial and their tubers can survive frosts in the ground, often sprouting unexpectedly in spring when you come to plant new crops.
Do potatoes like manure?
Potatoes love manure but it should always be well rotted. Fresh manure will burn seed potatoes and their new foliage before it reaches the soil.
If you have fresh manure, keep it somewhere where it can drain and get around 6 hours of light per day for 8-12 months before using it on the veg patch.
Now You Know How to Grow Potatoes
Potatoes are one of the most commonly grown vegetables in the garden, and there are plenty of easy ways to grow potatoes without much effort.
However, for the best potato harvests and bigger yields, follow the steps and instructions for how to grow potatoes in the article and you’ll pretty much guarantee a bigger crop next year.