A Growing Guide - How do I chit, plant, grow and harvest my potatoes?
It may seem daunting when first starting to grow your own potatoes with so much strange terminology and we have a growing guide to help you. Remember to keep notes of the weather and soil conditions and then you can tweak your plans for the following year. Growing your own vegetables is a great hobby for every age and potatoes are one of the easiest to grow.
Potatoes are categorised by their maturity (first early, second early, early main crop and main crop) and each variety on our site is marked with the maturity underneath as well as the cooking type. This information will also be on the label of your net. The different maturities are grown for different lengths of time before they are ready to harvest.
- Chitting is simply waking the seed potato up after its winter dormancy ready to grow.
- It is definitely a good idea to chit, but to do this you need to get your seed nice and early – maybe January or February if you are in the South of England and March or April if you are in North of Scotland. The aim is to have your potatoes come through the ground after the last frost in your area as the new plant is susceptible to frost.
- Chitted seed will be ready to grow much quicker once Spring arrives and the soil warms up. Chitted seed should come through the ground in about 2 weeks.
- If you buy your seed in April or May, however, then there is little or no advantage in chitting since the soil temperature will be ok for planting, though the unchitted seed will take c4 weeks to come through the ground.
- Remove the seed potatoes from the net as soon as you receive them (as the shoots will grow through the nets and can break if you try to remove them) and put them in an egg carton in a sunny window sill (make sure it is frost free if you are doing this in a greenhouse or shed). The shoots will start to sprout and when they are around an inch long they will be ready to plant.
We have a great video on How to Chit potatoes
There is nothing worse than looking at a potato every day that appears not to be sprouting.
Potatoes go through a period of natural dormancy after harvest and are only beginning to waken up in the spring. It also depends on the variety – some are “asleep” longer than others. Chitting wakes them up however, even if you have had your potatoes chitting since the start of January the natural cycle can only be altered slightly.
Just as the end product looks different, they will have different coloured flowers and be of different heights. The shoots will be different colours and will emerge at different times.
The database where we get all our information regarding disease information is the official Agriculture and Horticulture web, they are beginning to list dormancy, but this information is anecdotal and not complete, which is why we don’t include it.
Keep them on a sunny window sill and you will see growth soon 🙂 It may be just that the sun isn’t strong enough yet to stimulate growth. Be patient – spring is coming!
If you really think that your seed potatoes are not growing after a month of chitting, please send us some pics.
When to plant is a multi-million £££ question!
This is a jigsaw and depends on where you are! You need to work out the last frost date for your area and work backwards from there. We generally say later is fine! a lot of folk are caught out with late frosts in April and May – the young plant is susceptible to frost. However it really depends on where you live and personal preference – if you can keep the plants frost free by bringing them indoors or wrapping with fleece/old sheet etc. We have customers in Cornwall who are harvesting just as our customers in Northern Scotland are planting!
Mid-Feb till Mid-March is around average to start chitting and gives you 4-6 weeks to chit and then plant in late March /April if the forecast is looking good! However, delaying by a week or two would do no harm.
Earlies take around 100 days to mature and can be planted up until the end of June.
Main crop take around 4-5 months to mature and can be planted up till around mid May.
Main crop take around 4-5 months to mature and can be planted up till around mid May.
Again there are several trains of thought on when to plant. Some people will want to plant earlies in Mar/April to get a summer crop and then to plant their main crop later so they are maturing by the end of the summer. Some will stagger planting, and plant some each week, and others will plant their potatoes of all maturities on the same day. You need to work out what works best for you and it is advisable to keep a diary.
Late season varieties for a Christmas Harvest should be planted by mid August.
- You can plant potatoes up until June and even later if you have some late season ones. See our page how to choose for a description of the different crop types.
- There is a common myth that you can cut the tuber up to give a better yield. We do not advise this. Tubers have enough stored energy to get to the surface and produce a healthy crop. By cutting them you are risking the tuber going mouldy, as it has no skin to protect it, and lower yields.
- Potatoes like to be watered but not water-logged and so ensure your pot or area has good drainage.
- Potatoes need a sunny site away from frost pockets – the newly emerging foliage is susceptible to frost damage in April and May. The ground can be prepared the previous autumn or winter by digging in organic matter such as well-rotted animal manure or compost. Do not use an area that has had potatoes or tomatoes in it the previous year as some diseases can remain in the soil.
- The traditional planting method is to dig a narrow trench 12cm (5in) deep. The seed tubers are spaced 30cm (12in) apart for earlies and 37cm (15in) for maincrop varieties in rows 24in (60cm) apart for earlies and 75cm (30in) apart for maincrop. Apply a general purpose fertiliser at this stage.
When the emerging shoots come through, you need to “earth” or “mound” them up – this is counter intuitive. Do this several times. This encourages downward growth.
Mounding or earthing up means drawing up soil around the stems as they grow – to protect shoots from frost damage in late spring and more importantly, new tubers are jostling for space and this gives them more room ensuring the developing potatoes aren’t exposed to light, which turns them green and inedible.
It’s a simple process – once the shoots are about 23cm (9in) tall, mound soil up around them to form a ridge along the row, leaving just the top 10cm (4in) of the plants visible. As the stems grow taller, repeat the process several times, a few weeks apart. The final height of the ridge should be 20–30cm (8–12in). Some people advocate covering the entire plant – you could experiment to see which works best for you.
- Small crops of potatoes can also be grown in large, deep containers, and this is a good way of getting an early batch of new potatoes. Fill the bottom 15cm (6in) of the container with potting compost and plant the seed potato just below this. As the new stems start growing, keep adding compost until the container is full.
Each variety has a different flower, but in some years they are absent or only appear briefly. This is down to lots of different factors such as weather and soil. Some varieties hardly flower even in optimum conditions. Potatoes are almost unique in that they do not need a flower to germinate in order to produce the next generation, the new tubers grow underground and are true to the parent. They may differ in size and colour, but the DNA of the new tubers will be true to the parent. No flower does not mean a failed crop.
After flowering, some plants will produce a seed pod which looks like a tomato. If planted, they could grow to be a potato, but the seedlings will not grow true to the parent – it will depend on what it was pollinated with – it will take 5 years and a lot of luck for something to produce new tubers – and even then they might not taste good. Just compost them. If you have curious toddlers around, it might be an idea to remove the pod in case they try to eat them . They are not poisonous to the touch. Breeders are the only people who need these and wouldn’t touch the ones on random plants. They have them pollinated in controlled environments so they know what has been x with what. We are breeding new potato varieties and you can read about it in our story page.
Blight! The curse of any gardener and allotmenteer!
Sign up for Blight Watch
According to The Royal Horticultural Society RHS, Potato and tomato blight, also known as late blight, attacks the foliage and fruit or tubers of tomatoes and potatoes, causing rotting. It is most common in wet weather. Blight is a disease caused by a fungus-like organism that spreads rapidly in the foliage and tubers or fruit of potatoes and tomatoes in wet weather, causing collapse and decay. Blight caused the Irish potato famine and as the word ‘famine’ suggests, blight can be devastating if not managed and dealt with quickly. In as little as 10 days, Blight can destroy your entire crop of potatoes,
The best way to avoid blight is to plant earlies as they will hopefully mature before blight arrives, or to grow blight resistant potatoes. Blight resistant potatoes are most definitely a thing and we use independent results when we state that some varieties are blight resistant. The picture from trial plots shows different varietes. Read more here.
A good start can help you to prevent blight in your potatoes. Choose an airy plot with a good amount of space between your potato plants. Rotating crops is also important, so don’t plant this year’s potatoes in the same place as last year’s.
In addition to good placement, as soon as blight forms it is important to remove and burn infected plants to prevent further spread. Please do not place infected plants in a compost bin or heap as Blight can and will travel!
What causes blight?
Blight loves warm, humid weather. the right mix of warmth and damp provides ideal breeding conditions for Blight to thrive. Late summer is usually the time when Blight becomes a real nuisance, however Blight can strike as early as May or June, in the UK, if the conditions are right.
Will a greenhouse protect my potatoes from blight?
The short answer is No. Whilst a greenhouse can offer some protection Blight really can and will get everywhere, so it is important to be just as vigilant for potato blight with potatoes grown inside as well as out. which is why Blightwatch provides you with daily alerts as to when Blight is likely to strike, meaning you can check your crop and deal with any infection.
Sign up for BLIGHT WATCH – The Blightwatch service is available to all users free of charge and you can register for the service by using the ‘Join Blightwatch’ section on the homepage by providing a name, email address and up to 10 postcode regions that you would like to receive alerts for.
If you suspect your plants have blight, take some pics and email to us or put on our social media and we will help you to ascertain whether you have blight. Blight in the leaves does not necessarily mean that you have blight in the tubers.
Please note that buying certified seed potatoes does not reduce the chances of getting blight. Also buying blight resistant potatoes does not mean that you won’t get blight – the chances are reduced.
The advice on the RHS site on how to avoid and identify scab is a fantastic resource. They recommend choosing varieties that are scab resistant and we have several of their recommendations. Remember that no variety will have 100% resistance. It is also worth asking neighbours or fellow allotment growers at your plot for their recommendations as anecdotal evidence may carry weight locally. Potatoes with scab may look awful, but it is perfectly safe to eat – you may want to peel them first.
With earlies, wait until the flowers open or the buds drop; the tubers are ready to harvest when they are the size of hens’ eggs. With maincrops for storage wait until the foliage turns yellow, then cut it and remove it. Leave for 10 days before harvesting the tubers – this allows the skin to set, leaving them to dry for a few hours before storing.
Early Potatoes do not store long and so should be eaten within a few days of harvest.
Once you have chopped the leaves down from the Main Crop, you can leave in the soil for a week to 10 days. This allows the skins to set. Do not wash them at this time as the soil will help to keep them in great condition. These will store for a few months in a cool (not freezing) dark place, such as in a shed, under the stair or utility room. Storing them in a box or hessian bag allows them still to breath – a plastic container would not allow airflow and they could go mouldy.
Our FAQ page has answers to many other questions you may have. We're here to help and so please contact us at any point if you have queries that aren't covered there.
Many customers post their questions with pictures on our social media pages. Questions like "Is this ready to harvest" are best with pictures.
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