By David Marks
Large potatoes, those used for baking, appear to be dwindling in popularity nowadays. Many gardeners also believe that they are becoming more difficult to grow for no apparent reason.There are four basic principles which will help you to achieve larger than normal potatoes. The two most important are stem density and the variety you choose. The remaining two are the nutrients present in the growing ground and the general growing conditions. All are explained in more detail below.


To grow a large potato you need to choose a variety which will continue to grow well in the ground over an extended period. Different varieties grow better in some areas compared to others. In general though the following varieties are likely to succeed:


When you plant a single seed potato you will end up with one potato plant. However that plant can have a variable number of underground stems which later appear above ground, anything from one to numerous stems, typically four or five but this varies between different varieties. Each stem can in reality be considered an individual plant although they are rarely called that.

To grow larger potatoes the plants need to be spaced at a larger than normal distance apart. This allows the plant to absorb more nutrients and water. One option therefore, to enourage larger potatoes, is to plant the seed potatoes 24in / 60cm apart compared to the normal recommended distance of 15in / 45cm.

Another option is to restrict the number of stems which grow from below ground to two or possibly one, but still plant the potatoes at the recommended distance of 15in / 45cm. To do this, rub off all but two sprouts (see here for more information about how to do that) before you plant each seed potato.

However, seed potatoes are well known for sprouting new shoots when existing ones have been rubbed out. To avoid new sprouts from growing, keep a watch on the plant when the shoots appear above ground. Restrict the shoots to only two by cutting off any excess shoots just below ground level.


Feed your potatoes with a nitrogen rich fertiliser at the beginning but then change to a potash (potassium) rich fertiliser such as tomato plant fertiliser. Specific dates are given below:

FEED WITH NITROGEN FERTILISER (e.g. Growmore) FROM the second week of MayTO the fourth week of June

FORTNIGHTLY POTASH FEED (e.g. tomato fertiliser) FROM
the second week of June TO early August 2017

As far as general growing conditions are concerned, these are as described on our general potato care page here.


Sometimes our readers ask specific questions which are not covered in the main article above. Our
Potato comment / question and answer page
lists their comments, questions and answers. At the end of that page there is also a form for you to submit any new question or comment you have.