Allotment Vegetable Growing Potatoes Brief Guide - earlies and maincrop, chitting and planting

Growing Potatoes Brief Guide

Potatoes

Unlike most vegetables, potatoes prefer the soil slightly acid so you want to put them at the far end of lime in your crop rotation. They are, however, greedy feeders so a goodly amount of manure or compost worked into the soil will help to feed them as well as improving the texture of the soil. See Potato Fertilizer Programme

The big benefit of growing potatoes must be the taste and you have a choice of over 400 varieties to choose from. A few hundred more than you will ever find in the shops. So you need to decide what you want to grow. First of all, ask other growers in your area what they do well with and like. Different varieties will grow better in some areas than others

Next take a look at Potatoes - What Varieties to Grow For Flavour to get an idea of what types are best for what and you can often buy small packs of 10 seed potatoes so you can try different types and find what you like.

Do not just try and plant potatoes from the supermarket. More often than not you will be wasting your time and missing an opportunity to taste something really special for your efforts. They may well have been treated to stop them growing anyway.

First Early, Second Early and Maincrop Potatoes

These terms often sound mysterious but they're not really. All the terms refer to is the time it takes from planting to getting a crop. First earlies are usually ready in around ten weeks, second earlies in around 13 weeks and maincrop after about 20 weeks.

Maincrop types tend to store better but they are at more risk of getting blight than the faster types, which are usually harvested before the blight periods begin. (see potato blight)

Chitting Potatoes

There is no mystery to this process. All it means is that when you get your seed potatoes you put them in a cool but frost free place where they get some light but not direct sunlight. A north facing window is ideal in a frost free shed.

The potatoes will then grow short stubby shoots, which will get them off to a fast start when planted out. Some people suggest rubbing off all but three shoots to help get larger potatoes with the maincrops. There is some evidence that chitting doesn't help greatly with maincrop potatoes but it certainly can't hurt to chit them.

Frost

Frost is a big enemy so you need to keep an eye on the weather. Usually mid-March is about the right time to plant your earlies and you plant the maincrop a few weeks later. If after planting the leaves, also called haulm, start to show through and frost threatens you need to protect the plants. You can do this by pulling earth over the haulm from the side or covering with fleece.

Planting Potatoes

To plant you can just make a hole with a trowel and pop the seed potato in or you can draw a trench (take a draw hoe and scrape a trench) and place the potatoes in it. You want it to be about 100mm deep. You then pull the soil from the sides to cover the potatoes.

If you have a comfrey patch try and get a cut of comfrey leaves, let them wilt for a day and just place them on the bottom of your trench, covering with a little soil. Comfrey will quickly rot down to provide fertiliser and it is almost perfect for potatoes and tomatoes.

Your first and second early potatoes should be planted about 300mm apart in rows about 600mm apart. The maincrop, being the heaviest cropper, need a bit more space so plant them about 400mm apart in rows 750mm apart.

Earthing Up Potatoes

As the plants grow you need to draw the earth from the sides of your rows over the plants. The potato tubers (that's what we call the actual potato you eat) tend to grow towards the surface and if light gets to them they will go green. You do not want to eat green potatoes as they may give you upset stomach, so "earthing up" as this is called will cover these tubers and increase your crop.

It won't hurt the plants when you cover some of the leaves by earthing up or slow down growth.

I mentioned they are greedy feeders and an additional dose of fertiliser after a month or so when they plants are established will really help. You can use specifically formulated potato fertiliser or an organic fertiliser such as fish, blood and bone. Good results can be had from using a liquid comfrey feed because the liquid is immediately available. See Potato Fertilizer Programme

In dry weather keep them well watered. They produce a lot of crop and need their water. If the water supply is irregular the yield will be reduced and the potatoes can be cracked from uneven growth.

You are now ready to harvest and store your potatoes.

Allotment Growing

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