Early earlies are a treat to be savoured – and to get them on your plate in April/May you need to make a start now in December/January.
Early potatoes have a short growing season – that is they will reach maturity within 10-12 weeks of planting depending on the severity of the weather. Colleen, Casablanca, Sharpe’s Express or Red Duke of York are all reliable, tasty early varieties. Orla and British Queens (although officially these are second early varieties) can also be planted now for an early crop.
Chitting is basically another word for sprouting. By exposing the seed potato
to light and a small bit of warmth you are encouraging growth. The eyes of the potato will start sprouting - the sprouts should be small, knobbly, and green/purple in colour. If you end up with long, white coloured sprouts, it means there’s not enough light.
Why do you chit potatoes?
It is advisable to chit earlies to “wake” them up, instead of putting them straight into a fairly cold soil. By getting the potato to sprout you have started off the growing process so that the plants will have a head start when you put them in the soil.
How to chit potatoes
Potatoes will start chitting when exposed to light and heat, so place them somewhere warm and light. A temperature of around 8C-10C is fine. A porch, conservatory or a garage, getting a bit of heat from your house is ideal, or you could use your greenhouse if you’ve got one. Avoid locations that might get frost.
Place the seed potatoes in a single layer with a large amount of eyes facing up. If you’ve only got a small amount of seed potatoes, recycling old egg boxes for this purpose is ideal. For larger amounts, use seed trays or wooden boxes. Keep the tubers upright by supporting them against each other.
Once each of your seed potatoes have got 2-3 good sized ‘chits’ or sprouts on them (about 2cm), it’s time to plant. If any tubers have more than 3 chits/sprouts on them, rub the excess off. If you leave all the shoots intact, there’s too much competition – you’ll end up with lots of potatoes, but they’ll all be small.
Potatoes cannot stand frost - but they don’t need a lot of heat either. Root growth occurs when soil temperatures are between 10 to 35?C, but the best, most active root development is at soil temperatures of between 15 and 20?C. These lower temperatures are a possibility in tunnels or glasshouses during a mild winter in Ireland.
Early potatoes will need protecting from frosts. You can use straw or newspaper to protect them – but the easiest way is to have some garden covering (fleece) to hand. This cover will trap heat on sunny days and protect against 2-3?C frost on cold nights/days. If a serious frost is forecast it is advisable to use at least two layers.
The leaves of potatoes are very delicate so as soon as you have shoots out of the ground have your cover ready. The most devastating effect is when the sunlight thaws out (slightly) frozen leaves. The cover helps here too, by shielding the leaves from direct sunlight and slowing down the thawing process.
Fertility of soil
Potatoes are a hungry crop and like fertile soil. Well rotted farm-yard manure would be perfect or alternatively you can use a well balanced organic fertilizer such as Topmix4-3-7 or Vegan Plant Based Fertilizer5-3-8. Spreading rates - 25kgFYM/10m2 or 2.5kg of 4-37 or 5-3-8/10m2
Keep in mind you vegetable rotation when planting. Best practice would be to dedicate no more than a quarter of the greenhouse to potatoes, so that every four years they can be grown in a fresh spot.
Plant your chitted potatoes by digging a trench 7.5-13cm deep. Don’t plant too deep as the soil will be too cold and growth will be slow. It is better to plant potatoes shallow and earth up as the plant is developing, make sure that there is enough soil for this. Spacing is 30cm apart in rows 60cm apart. Always place the tubers/seed potatoes with the sprouts up.
Potatoes can also be planted in containers. Plant enough potatoes to fit the size of container you are using. You could fit 3 in a 40cm pot, one in a 25cm pot. Add gravel to the base of the pot followed by 4-10cm of compost. Place the potatoes around the edge of the container and cover with 10-20cm of the same compost.
Earthing up increases the number of potatoes grown from each tuber and protects them from sun exposure, which would turn them green.
When shoots are showing 10cms above the soil or compost, cover them with more soil or compost leaving 4cm shoots showing at the tip. Continue to “earth up” each time the roots are 10cms above the compost, if you are growing in a container you will ‘earth up’ until you are 4-5cm from the rim of the container.
Watering your Potatoes
Potatoes will rot if they are over watered, but they do require a constant supply of water, especially when they are flowering and potatoes are forming. When using a drip system, lay the pipe on top of the drills.
The crop will be ready for harvest from April, best to try one plant first and see what the crop looks like. Early potatoes are full of flavour and best eaten soon after harvesting, so only harvest small amounts at the time.
Absolutely delicious scraped clean and gently boiled. Serve with a sprinkle of sea salt and butter. They are also good roasted with olive oil and rosemary and garlic.