Potatoes are a classic kitchen staple, and one that’s easy for most people to try growing at home, whether it’s a single plant on a balcony, a patch in a garden, or a giant potato bed on a lifestyle block. This is a full circle lifecycle guide on how to grow your own potatoes. We’ll start with selecting and sourcing, chitting seed potatoes, prepping your pots or garden beds, planting out, and carry you all the way through to harvest and storage. Let’s dig in!
Picking Your Potato Varieties
Different potato varieties have different colours, textures, cooking properties, and even subtely different tastes. How do you like to eat your potatoes? How long is your season? Do you just want a few plants for fresh potatoes, or do you have space and hopes for post harvest storage?
Different potato varieties can also have very different timeframes from planting through to harvest. This can help stagger the maturity period for your potato plants. You can spread out your fresh harvest throughout the summer and into autumn, before shifting into storage mode.
Generally, in our climate, the potato options are grouped as early (approximately three months), middle (approximately four months), or late harvest (five or more months). That means you could get an early variety planted in spring and be eating your own potatoes before Christmas. And, if your space allows, you could stagger your potato harvests all the way until next frost.
Options for Propagating
Certified Seed Potatoes
This is the low risk option for growing your own potatoes. Certified seed potatoes are inexpensive vs. their potential yields, and are guaranteed to be disease and virus-free for a heathy start. You’ll know the exact variety that you’re planting, their harvest window, etc. But, most importantly, you’ll know that you’re not going to be introducing any nasties to your garden.
Saved Home Grown Potatoes
If you store your own potatoes through winter, you can use some for the next season’s chitting and planting. If you’re confident that your previous potato crop didn’t have any health problems, then you’re unlikely to accidently introduce anything new and nasty. And, with any luck, you’ve kept garden records and know what types of potatoes you’ve saved and would be planting.
Gifted Potatoes
Your trust in these is a good as your trust in the person who grew them and gifted them to you. Perhaps a little more confident than buying from a shop, but not always as certain as starting with your own or with certified seed potatoes.
Purchased Potatoes from Grocery/Produce Retailers
You can plant just about any potato and take your chances on what you’re growing (and if it’s unknowingly carrying any nasties). Organic gardeners can take the extra precaution of buying from an organic supplier to start their plants with organic parent potatoes.
Chitting Potatoes
To Chit or Not to Chit?
If you have time, chitting (sprouting) the potatoes before you plant them will speed things up from planting through to harvest. But nature would just start the last season’s potatoes growing in the soil when the conditions were right. There’s nothing wrong with following nature’s lead and just planting your potatoes straight out into the garden when ready.
Chitting let’s you get the germination and growing process underway before you’re ready to get the potatoes planted out, which can be extra helpful if you’re keen on an early harvest, growing long season varieties, or have a short growing season.
How to Chit (Pre-Sprout) Potatoes
Spread your seed potatoes spaced out on some cardboard or newspaper. Keep them somewhere dry and dark (or at least out of direct light) until they start growing sprouts from their eyes. Easy as! Don’t worry if the seed potatoes start to look a bit wrinkly or soft at the sprouted stage, they’re tranferring their resources into the new growth.
Ideally, you’ll plant them out when the sprouts are a few centemeters long. Handle with care after sprouting and during planting so that you don’t accidently break the sprouts off.
You can start the process around a month before you’re planning to plant. But don’t stress too much on precise schedule. They can go out earlier or hold on at the chitting stage for a while longer if you’re still not quite ready when they are. Cool conditions will help to slow the sprouts.
Whole or Cut? You can cut pieces with multiple eyes from larger potatoes to start more seedlings with fewer seed potatoes. Unless you have a lot of space, you might not want or need to cut your seed potatoes, but cutting can multiply the plants per potato. Make sure the seed potatoes are in good condition, make clean cuts, let the cut sides dry. Some gardeners like to treat the cut side to reduce the risk of rot or disease using wood ash, sulpher, or other.
Planning and Preparing a Potato Planter or Bed
Digging Down or Starting Low
Potatoes often grow better when they’re mounded up during development, creating sturdier stems for healthier stronger plants and (potentially) developing more tubers underground.
If you’re planting into an existing bed or into ground without any soggy soil issues, dig down and create a trench up around 20-30cm deep before you plant. You can go shallower and use a combination of trenching and mounding for total depth if that’s better suited for your soil and position. If it’s good healthy soil and you have enough space, you can move the soil just to the side of the tench for backfilling. If not, you can shift it elsewhere nearby for reuse.
Trenching will make the process of incrementally mounding up the plants during early growth easier, but it also nestles the roots deeper into the soil than a raised mound. This can help stabalise temperatures and maintain even moisture around the roots during hot dry weather.
Similarly, if you’re starting off a brand new raised bed or planting into a container, don’t fill it up with soil before you plant your potatoes. Start low, similar to the trenching depth, if possible. Prep with nice base of great quality soil, and then incrementally top it up as the plants develop.
Aspect and Spread
If your available garden space allows, potato plants like to grow in full sun. A semi-open location with good airflow and/or plant spacing can help to reduce the risk of fungal diseases, like blight. They’re upright growers and don’t have a huge spread, but they can pend into a semi-sprawl and will droop into dieback late in the season if main or late croppers, so allowing space around them is helpful, if possible. Mine tend to droop past their beds and stretch into nearby pathways.
Soil Preferences
Like most root crops, potato plants enjoy loose rich soil with good drainage to avoid rot. Set your starting depth, as noted above, for incremental mounding/backfilling to your final growing soil height. You can bulk prep the soil your beds (or refresh your existing soil) to get it ready for planting and future mounding and filling. I like to keep a pile of ready-use soil on stand-by for mounding up as needed during the early stages of growth.
Too much nitrogen can cause them to grow great leafy stems but not produce a good crop, so prep your soil and feed with care. Potatoes need a nutrient balance with potassium and phosphorus for a good crop, so you might want to use a potato-specific fertiliser if you’re adding a commercial product. Prepping your beds with a good starter soil and then slowly feeding your garden throughout their main growth period can help to set you up for a successful harvest.
Planting Out the Potatoes
You can plant out your potatoes in late winter for temperate areas, or in springtime for colder regions, once the soil is workable and when the risk of frost will be past by the time there’s exposed growth. You don’t want to freeze your tubers or have your young plants hit with a frost.
Planting later is a-ok too if you’re planting on a planned stagger, or just decide to make a late start with a quick growing variety. As long as they should have enough time to produce, go for it.
Plant the potatoes in a row approximately 20-30 cm apart. If you have dominant sprouts you can position them upwards. Otherwise, just take your chances and pop them in sideways and let nature sort itself out. Cover them with a few centimeters of soil, water your new garden, and wait for the plants to start poking through before incrementally adding more soil.
Backfilling and Mounding During Early Growth
Incrementally, as the leaves start to develop and poke through the soil, keep backfilling your trench and or topping up your low beds and planters. If this is new to you, it might freak you out a little to be burying your precious young potato plants, but don’t worry. They’ll quickly grow up through again and be all the stronger for your early backfilling or mounding efforts.
Filling up or hilling up, or a mix of fill then hill, will give your plants deeper stronger roots. And the roots are where the tasty tubers will grow, and we want those happy and well-away from the surface and any risk of sunburn. It also helps create sturdier plants, which can be helpful to reduce flopping or leaning foliage (and space hogging).
As new shoots emerge through the soil, keep periodically adding more soil until you’ve reached the full or finished height for your trenches, beds, and/or mounds. Then let the emerging seedlings carry on with their strong and hopefully healthy growth and development.
Caring for Potato Plants in the Garden
Watering Potato Plants
Keep your potato plants evenly hydrated, watering on an as-needed basis through the growing cycle. They don’t like soggy soils, but they do like to be well-hydrated. It’s ok for the upper few cm of soil to dry between waterings, but at the main root level, aim for consistently moist. Prolongued dry spells and/or erratic watering can lead to issues like hollow heart, thickened skins, or scaling.
Planting in raised beds or in mounds can help with drainage if your garden is prone to soggy soils, or trenching can help to moderate conditions at the roots if your garden is prone to dry sizzling summers (or if you’ll be unable to consistently monitor and water as-needed).
Avoid watering the plants from above, if possible. Wet foliage can contribute to fungal diseases like blight. Potatoes, like their cousins the tomatoes, can be hit by early and light blights in their growing cycles, so be wary and watchful. More on pests and diseases below.
Late in the growing season, when the foliage starts to die back or when you’re prepping for harvest, you can ease off on the watering as part of the pre-harvest prep and hardening.
Feeding Potato Plants
Potatoes are nutrient hungry plants, and can be lightly fed every few weeks throughout their main growing periods. You can feed with natural boosters, like seaweed solution or compost tea, and/or use a potato fertiliser. Follow the product directions for application.
As noted above, too much nitrogen can reduce your potato harvest, so feed potatoes and other root veggies with care. Using a targeted potato fertiliser will give the boost of key nutrients, like phosphorus and potassium, to help your potato plants produce a good crop.
Pinching
This is not an essential, but if you have time to pinch your plants during chores or checks (like pest patrol below), why not? I like to pinch off the flower buds and flowers from my potato plants. They’re drawing nutrients and energy from the plant and they’re not adding any value to our harvest growing underground. You can give the young stem tips a pinch too, if things are looking a little leggy early on in the plant’s development, to encourage bushier sturdier plants.
Watching for Pests and Problems
General purpose pests, like aphids, can attach potato plants. But the current scourge of home gardners and commercial growers here in New Zealand are tomato potato psyllids (TPP). We had TPP hit our tomatoes one year, terrible. Keep an eye on your plants for lurking psyllids, eggs, nymphs, or their tell-tale sticky sugary crystal residue. Treating the plants and/or soil with preventative neem might also help to keep them away or limit their damage and spread.
Other pests like weevils, wireworm, and soil-dwelling larvae can attack potato and other root crops underground. For gardeners who don’t like using chemicals or drenches, crop rotation, soil cultivation, and test trapping can be used. Some cover crops or companion plants, like mustard, may act as deterrants. Treating the soil with neem might also help keep them away or limit their damage and spread. See the notes later in this post on preparing for replanting.
Monitoring for Risk of Frost
Mature potato plants can usually handle a light frost. You might get some leaf or tip burning, but the plant will likely survive and the potatoes will be ok underground. If there is a risk of hard frost before you’re ready to harvest, consider covering the plants for protection.
Harvesting Your Potatoes
Time Until Harvest
The time from planting until harvest will depend on the variety of potato you choose, as noted earlier on selecting varieties. This can help you stagger the maturity period for your potato plants throughout the summer and into autumn or early winter.
Early harvest potatoes and new/baby potatoes of other varieties are ready to start digging out when the plant reaches flower, if it’s a flowering variety. This is usually around three months from planting. Main and late cropping varieties will usually die back at the end of their season and that’s the signal that to harvest your potatoes, if you haven’t already started.
Early Harvests and Crop Checks
Craving some fresh home grown baby potatoes? Getting a little impatient for harvest time? You can fossick around the soil under the plants gently by hand to feel for a few tubers to break away and dig out for an early meal. Or several meals. Hehehe. I do like to raid before harvest.
If your potato plant is of a flowering variety, setting flowers is a signal that baby potatoes are growing under ground. If you’ve planted an early ropper that isn’t well-suited for storage or if you want to enjoy the crop as new potatoes rather than as a main harvest for storage, you can start harvesting at this stage rather than as a main crop below.
Main Potato Crop Harvest
The main harvest time will depend on the variety, as noted above. In most cases, you’ll see the plant start to yellow off and die back as it reaches the end of its growing cycle. If this isn’t happening or it isn’t happening fast enough, you can cut back the stems shortly before you’re planned harvest to help the potato plant naturally harden off its tubers pre-harvest.
If the weather cooperates, harvest after a few days without rain or watering. Rather than forking, for smaller beds, I prefer doing this by hand to reduce the risk of damage, and then turning over the soil for a final check and collection of anything that’s been missed on the first pass.
Inspecting for Damage
Damaged potatoes or potatoes with young soft skins won’t store well. New potatoes and anything that’s accidentally damaged during your main harvest, if otherwise healthy and firm, should be eaten or processed straight away for alternative storage methods, like freezing.
Storing Potatoes Through Autumn/Winter
Curing Potatoes After Digging
After you’ve checked and removed any damaged potatoes, the rest of the mature crop can be left to dry and cure briefly before storage. You can brush off excess dirt, but there’s no need to wash residual dry dirt. Washing can actually shorten your storage life. It goes against all my internal desire to clean, but if a little dirt helps them to store a little longer, I’ll allow it.
Dry and cure the potatoes somewhere sheltered, warm, and dry, ideally out of direct sunlight, for a few days. Once ready, you can gently brush away excess dirt (I use a soft paintbrush) before storage. Check for any signs of softening or damage that you missed on the initial inspection.
Storage Conditions
Store your potatoes somewhere cool, dark, and dry, and make sure that no pesky critters can get to them for nibbling. If you’re not using them quickly, check on your stored potatoes every now and then, and remove anything that’s starting to spoil or getting squishy. With ideal storage, they’ll last for months, but their condition will slowly decline over time.
Getting Ready for Next Season
Propagating from Your Harvest
In most places, including here, you’ll have several months as a gap before it’s time to start chitting again for the next planting season. If you’re keen to propagate from your own potatoes, with any luck, you’ll be able to overwinter some healthy potatoes in storage. If not or if you had crop health issues, it’s better to start fresh with some certified seed potatoes or another source.
Crop Rotation Plans
In an ideal world, you’d have space to shift around your potato planting areas from year to year, alternating at least every other year, and ideally longer. Crop rotation reduces the risk of carrying over pests or diseases, and gives you longer to recondition the soil. If you’ve had issues, like scab or wireworm, the longer the gap the better. You might even want to take some time off.
In planning your rotations, remember that potatoes are from the same solonaceae family as some of our other summer favourites, like tomatoes, peppers, and eggplant. These plants share common pests and diseases and shouldn’t be rotated into each others spaces, if possible.
But the world isn’t always ideal. If you need to reuse the same beds or are limited on rotation options within plant family groupings, be extra vigilant in monitoring for any problems and use the offseason to alternate, replace, or amend the soil.
Preparing Soil for Replanting
Make sure that all of the potatoes have been been dug out and any other plant matter is removed from the bed(s) at the end of the growing season to reduce transfer risks.
The next year’s crop will require the same nutrients as this year’s crop depleted, you’ll want to replenish the soil before replanting. You can use top up soils, compost, fertiliser, etc. and remember that potato plants like lots of phosphorus and potassium for tuber development and not too much nitrogen. Consider working in some organic matter through the offseason and adding a potato-specific fertiliser for a targeted boost before you replant.
If your weather and space allow, you can grow short-season winter veggies or grow a sacrificial winter cover crop in the bed. Ideally, use plants that potato pests, like wireworm, don’t enjoy. Mustard is a good winter cover crop here (we use it ourselves), and it can have a mild soil cleansing effect to help with potential pests. It’s easy to germinate from seed, tolerant of cold temperatures and light frosts, and low maintenance grower until you’re ready to cut or compost.
