How to Chit Potato Seed

The chitting of seed potatoes, or potato tubers, is a process that involves laying seed potatoes out in a light, cool and airy environment, to encourage early sprouting ahead of planting. This process breaks the dormancy that seed potatoes are in when they are first sold.

The purpose of encouraging this premature growth is to give the planting material, a head start when it comes to planting time.

If chitting is started during January, seed potatoes can easily have 3-4cm of new growth when they are planted out in March or early April.

You can discover more in this 'How to Chit Potato Seed' Video

The simple answer is no.

It is very rarely carried out in the commercial potato industry and is by no means a given that it needs to be carried out on the allotment.

Any potato crop, if grown well, will result in a decent crop in a normal season.

Because chitted seed has premature growth at planting time, it will, however, be ready for harvest in fewer growing weeks than a crop that has been planted straight from the bag.

This chitting process is therefore very beneficial to early or second-early varieties, but less important for maincrop varieties.

In some growing seasons, the chitting of seed potatoes can result in slightly heavier yields but this may differ between varieties.

Seed potatoes are available for purchase soon after Christmas and until they are sold out in April.

If you are searching for a potato seed, GrowMad has an extensive list of potential seed potato suppliers here.

Chitting seed potatoes is a straightforward routine but growing several varieties may take up a lot of space.

The potato tubers should be placed in trays with the 'rose end' facing upwards. The rose end or apical end is a term given to the potato that describes the point furthest away from where it was attached when growing. This also happens to be the point at which most new shoots will sprout.

Used egg boxes make excellent trays for placing seed potatoes into but any shallow box or seed tray will suffice.

Don't forget to label the trays, especially if chitting more than one variety and it's always a good idea to keep records so that you can compare notes at harvest time or from season to season.

You can find a list of label supply companies here and we have a GrowMad labelling and record-keeping article available here.

Place the trays of labelled seed potatoes in a dry, light spot that is cool-ambient but at all times, frost-free. A greenhouse. conservatory, porch or spare bedroom will all be suitable.

Start chitting your seed potatoes approximately 6 weeks before the required planting date.

During January, after a period of 2-3 weeks, shoots will start to appear. Later batches may sprout a lot quicker.

By March, the tubers should be well-sprouted and ready for planting.

Having too many shoots is undesirable and will result in harvests of lots of small tubers. For optimum harvests, rub off excess shoots leaving a maximum of 3-4 of the strongest.

You can discover more information on growing potatoes in this GrowMad Growing Guide.

Insufficient light when chitting will cause the shoots to stretch and become weak.

At planting time this will cause inevitable damage to the shoots defeating the point of chitting in the first place.

Ensure there is enough light.

Frost damage will kill off any shoot development and extreme cases can kill the entire potato tuber.

Seed potatoes do not need to be too warm to chit but will not tolerate sub-zero temperatures. Keep at ambient room temperature and avoid frost.

Aphids can be an issue with seed potatoes that are allowed to chit later in the season. Aphids can act as vectors for the spread of plant viruses that will affect the growing crop at later stages in the crop cycle.

Any aphids that materialise during the chitting stage should be carefully washed off under a tap before planting.