Noah Chase studied horticulture at the Eden Project in Cornwall, England. He now co-manages a family run nursery, Deelish Garden Centre in Skibbereen, specialising in rare, unusual and edible plants. His passion is sustainable gardening, useful plants and care of the environment.
As the days get longer and hopefully dryer, we start to plan and dream of what we would like to grow in the season ahead. One of my favorite vegetables to grow are Potatoes aka Spuds!
For the amount of space and work invested, potatoes have to be one of the best choices to grow in your garden. If the ground is in its first year of being used to grow vegatables, between your own digging and the growth of the tubers, the soil structure will greatly increase, making lighter work for the following season.
Let’s have a look at the main types of seed potatoes, as sometimes this can cause some confusion. Basically they are put in diffrent groups depending on how long from planting to your plate!
• Plant early to mid March.
• 10-12 weeks to mature.
• Less chance of blight but smaller harvest.
• Plant mid March to early April.
• 12- 14 weeks to mature.
• Small chance of blight.
• Good selection
• Medium harvest.
• Plant in April.
• 18-22 weeks to mature.
• More chance of blight.
• Large harvest
The above is a general guide but will vary depending on weather conditions and how late into the season you get frosts. If the new shoots will get blackened by a late frost the crop may not recover. As a general rule, I try and plant out around St. Patrick’s Day. There are literally hundreds of varieties to choose from and this really comes down to personal taste, in any case it’s important to buy seed potatoes as these are guarenteed to be certified virus free.
Seed potatoes, particularly earlies and second earlies, benefit from ‘chitting’ prior to being planted. This process encourages strong shoots to sprout over several weeks to encourage faster growth and heavier crops once they’re in the ground.
From late January/February, chit your seed potatoes by setting them out in seed trays, shallow boxes or empty egg cartons in a cool, bright, frost free position to allow them to sprout. You will notice that the immature ‘chits’ are all at one end (called the rose end). Place the rose end upwards. Sturdy ‘chits’ will form and should grow 1” in length. Be careful not to let them get any longer, as they can break when planting out, slowing down the growth. Main crops don’t necessarily need to be chitted.
Once you are happy with your chitted seed potatoes and the weather seems right, you are ready to plant! The soil should be freshly dug over and weed free. The traditional way is to dig a narrow trench 12cm (5”) deep. This can be lined with compost or even grass chippings for a better crop. As potatoes are hungry growers, I also add Greenvale pellets (a mix of chicken pellets and seaweed dust) to trench at this stage. If possible a mulch of well-rotted manure topped with seaweed would be even better. The see tubers are spaced 30cm (12in) apart for earlies and 37 cm (15in) apart for maincrop varieties in rows 60cm (24in) apart for earlies and 75 cm (30in) apart for maincrop.
There are other ways of growing if you do not have a large garden, or any garden at all! Small crops of potatoes can be grown in large, deep containers (rubble sacks and stacked tyres also work) and this is a good way of getting an early batch of new potatoes. Line the bottom 15 cm (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.
It is important to earth up potato crops, as the shoots emerge above ground, to protect them from frosts which blacken the shoots and delay production. Simply draw some soil over the top of the shoots to cover them again.
If there is a chance of a late frost, cover the new shoots with a garden fleece or straw. Remove when the threat of frost has passed.
First earlies and second earlies in particular require plenty of water during prolonged dry weather especially when tubers are starting to form. This is also a good time to feed with an organic liquid concentrate. This will strengthen the plants against disease and improve yields.
When the stems reach a height of 23cm (9in) above ground they should be earthed up again to prevent tubers near to the soil surface from turning green.
Weed out any unwanted plants along the trenches through the season (if the potatoes are growing well, there wont be many).
Lifting times will vary depending on the growing season, weather conditions at harvest time and the size of tuber you want. Start to harvest first earlies as ‘new potatoes’ when the plants begin to flower, approximately 10-12 weeks from planting. Tubers will generally become larger the longer their growing period.
Maincrop varieties are usually left for at least two weeks after the leaves and stems have withered, to allow the skins to set. Cut down the stems with secateurs to just above soil level as the leaves wither and yellow, or if they show signs of blight. After harvesting, leave the tubers on the soil surface for a few hours to dry and cure the skin. Once dry store them in paper or hessian sacks in a dark, cool but frost free place. Avoid storing in polythene bags as potatoes will ‘sweat’ and rot.
Potato blight: This is the most common disease in our wet, warm summers. The initial symptoms are a rapidly spreading brown watery rot, affecting the leaves and stems. Tubers can be affected too, and have a reddish-brown decay below the skin, firm at first but soon developing into a soft rot.
Remedy: Spray potato crops with a protective fungicide even before signs of blight become apparent. Copper sulphate is used as a preventative, not a cure. Add 50g Bluestone (copper sulphate) to 2 litres of hot water. In a separate container add 60g of washing soda to 3 litres of hot water. After half an hour, mix the two liquids and spray directly onto the potatoes, making sure to spray under the leaves as well. Do not spray if raining as the mixture will not stick. Use a watering can in the absence of a sprayer and ensure to clean it thoroughly after use. This five litre mixture is enough for 20 square metres. Begin spraying this potato blight treatment from about June, particularly when periods of wet weather are forecast and spray again after a few weeks to protect any new growth. We have also had great feedback from gardeners spraying with horsetail concentrate.
Horsetail concentrate recipe: mix half a cup of dried horsetail leaves in five litres of water, bring it to the boil and simmer for half an hour. Cool, strain and bottle. It should keep for a month
This year, I plan to trial homeopathic remedies, Carbo Veg and Silica, in water dilute as a plant spray (based on positive results from gardeners who have tried this).
If plants become infected they should be removed and destroyed. Where potato crops have already developed tubers then these can be saved by cutting away the foliage and stems. Leave the soil undisturbed for two-three weeks to kill off any lingering spores so that they don’t infect the crop when it is lifted.
Always try and grow potatoes on new ground or rotate every year if possible for the same reason.
Potato blackleg: Potato blackleg is a common bacterial disease which causes black rotting at the stem base. Initial infections cause stunted growth and yellowing stems. If tubers form, the flesh may be grey or brown and rotten.
Remedy: Blackleg generally infects individual plants rather than entire crops and does not spread between plants or persist in the soil. Remove and destroy any infected plants, improve soil drainage and plant blackleg resistant potato varieties.
Potato scab: This disease causes raised scab-like lesions on the potato surface. It does not affect the taste of the potato, and is easily removed on peeling.
Remedy: Common Scab on potatoes is best controlled by improving poor soil conditions with the addition of organic matter and by keeping potato crops well watered throughout the growing season. Use any infected tubers first and do not store them.
Eelworm: Initially, crops display patches of poor growth and affected plants may show chlorosis and wilting, with poor top growth. These symptoms develop from the ground upwards. Heavily infested plants die prematurely and yield a poor crop of under-sized tubers.
Remedy: There are no pesticides available to home gardeners which will control eelworms, and so crop rotation should be used to avoid spreading the pest and to reduce infestations. Some varieties are more resistant.
Slugs: Slugs cause damage to both the foliage and to the developing potato tubers. Damage is fairly obvious as the culprits are easily identified by the silvery slime trails that are left around the plant foliage and on the soil surface.
Remedy: There are a multitude of ways to kill or remove slugs and snails including homemade remedies such as beer traps. Use eco friendly slug pellets or you can try nematodes or copper barriers.
Below are some of our most popular varieties. Just like the gardeners who grow them , there are lots to choose from and each has their own qualites!
Arran pilot: Old fashion favorite. Scab resistant. Good boiler.
Colleen: Uniform tubers. Good disease resistance.
Duke of York: Tasty yellow flesh. Good roasting potato.
Orla: Great for boiling. Stores well.
Sharpes express: Used for boiling salads and chipping.
British queens: Loved all over Ireland!
Catriona: Excellent flavor. Big tubers.
Charlotte: Popular salad variety. Boils well.
Kestrel: Early and high yielding. Slug resistant.
Nicola: Buttery flavor. My favourite!
Cara: Baking and boiling potato. Eelworm resistant.
Desiree: Most popular red. Drought resistant.
Kerr’s pink: Pink skin. Great all rounder.
Pink fir apple: Unusual shape. Nutty flavor.
Setanta: Blight resistance. Floury red.
Bred for their resistance to blight. High yielding. Excellent storage. Main crop. Not to everyone’s taste!
Sarpo mira: Highest blight resistance. Floury.
Blue Danube: Blue skin white flesh.Great roasted.
Axona: Red skin. Baking, roasting chipping and mash.
So, as you can see there are lots of varieties to choose from. All that’s left to do is to pick the varities that would suit your taste.
Wishing you all the best with the growing season ahead and remember gardening dosen’t have to cost the earth!