How to grow swedes

How to grow swedes: a simple guide

Swedes, (commonly referred to as turnips here in Northern Ireland) are a great root crop to grow in colder climates. It starts with getting your soil right, having a strategy in place for weeds, and knowing the best way to sow them. I have made a simple list of the main points you should take into consideration to help you grow a good crop.

Preparing the Soil

Good soil makes for good swedes. They like soil that lets water through easily but keeps enough nutrients to grow well, such as loam. Test your soil to see if it’s slightly acidic to neutral (pH 6.0 to 7.0 is perfect).


If the land has a lot of weeds, it is a good idea to spray them with a herbicide such as glyphosate 3 to 4 weeks before ploughing. If your soil is relatively weed free and you can plough to completely invert the soil then perhaps you don’t need to spray.


If you are going to add farmyard manure, it is best to have added it before ploughing. If you are using chemical fertiliser then you can either broadcast it or apply it with an applicator into the drills or bed just before sowing.


Using a precision sower, I place the seeds exactly where I want them, avoiding the need to thin them out later. This means each swede has its own space to grow from the start. Plant them late spring to early summer, so they have time to mature before it gets too cold. The best time to do that here in Northern Ireland is late April to end of May.


After the swedes are sown I always apply a pre-emergence weed spray such as Butisan, this helps keep the weeds away for a few weeks to give the swede seedlings a chance to get ahead of them.

Looking After Your Crop

Our weather usually provides enough water for swedes, but keep an eye on them. If it’s really dry, and the swedes have just been sown there may be issues with germination unless you have access to irrigation.

Boron may need to be applied to the crop to avoid issues with brown heart. It can be applied using a boronated fertiliser or by adding a boron liquid to the crop sprayer. If using the crop sprayer it may need to be applied two or three times until they are ready to harvest.

Checking on your swedes for any signs of pests or disease is important too. Catching any problems early means you can deal with them before they harm your crop.


By late autumn, (September to October) your swedes should be ready to harvest. They’ll be firm and the right size 150mm to 200mm in diameter. When harvesting handle them gently to avoid bruises or damage.


Once harvested, keep your swedes somewhere cool, but not too dry. The swedes should be relatively clean from muck and don’t let any tops sit in the pile as these will rot and will cause the swedes touching them to rot as well. It is very important to remove the tops when storing swedes, store them in ton boxes or in a pile. Swedes like being kept in low temperatures.

Key points…

Growing great swedes starts with the soil. They love nutrient-rich, well-drained loam with a pH of 6.0 to 7.0. Precision sowing with a sower ensures proper spacing. Late spring to early summer is prime planting time. Post-sowing, a pre-emergence weed spray helps control unwanted plants, while monitoring for pests and diseases is crucial for healthy crops. Harvest in late autumn when swedes are firm and the right size. After harvest, store swedes in a cool, moist environment, removing tops to prevent rot.