Growing Onions & Shallots

onions growing in the soilNow that we’ve all recovered from the festive season it’s time to get back to the garden and start thinking about the spring and summer months which will be here before we know it. Today we look at growing onions and shallots.

When to plant Onions and Shallots

There are two perfect times to lay in onions- in the autumn and the spring. If you are fortunate enough to have a greenhouse you can start planting this month. You can start bringing seed on in trays indoors now and they will be ready to plant in spring. Shallots can be comfortably planted outdoors now but typically the best time of year is early/mid-February.

How to Plant Onions and Shallots

Tray Planting

If you are growing from seed then you will want to use modular seed trays and plant 5 seeds in each module. This will give you more than enough plants for a few rows of onions. Bear in mind that shallots grow in clusters whilst onions grow individually.

To plant seeds just mix in some damp seed compost and away you go – these are quite hardy plants thankfully. For more information on planting seeds find our guide for Sowing Seeds on our tips page.

Set Planting

For the easiest results sets are the perfect way to plant out onions and shallots. We’ll have a good choice of sets available to buy from mid-January so call in and see what takes your fancy. Alternatively wait for you seeds to develop and then you can plant outdoors.


Alliums prefer well drained soil with lots of sunlight – if there’s a chance of your soil getting too damp you can plant them in raised ridges of turned soil as this will prevent the soil retaining too much water. Ideally, they want to be planted with plenty of manure and compost turned into the soil at least a month beforehand. If you’re planning to plant in the spring now would be the perfect time to dig out your wellies and the garden fork and start preparing the earth. Alliums don’t like lots of nitrogen so shouldn’t be planted with fresh manure – though they are honestly so resilient it’s not the end of the world!

To plant onions or shallots create shallow drills that will fit the plants in comfortably. Work the soil back around the plants so that only the neck is showing. Water gently but don’t drown them!

Onions and shallots should be spaced with each set 4 inches apart and each row 10 inches apart to ensure good growth. If you want to reduce the risk of some diseases, you can mix plant the onions with carrots as carrots disguise the smell of onions reducing the risk of onion fly.

Caring for Onions and Shallots

Onions and shallots aren’t great at tackling weeds thanks to the way their leaves grow. This means you’ll have to weed regularly to get the most from your crop. There are several diseases that can affect your plants but the most serious is White Rot. White Rot appears on the root and bulb as a fungus. If you spot this you’ll need to remove the crop, burn it and not grow onions for 8 years! Generally other diseases won’t ruin your crop – though sets are a lot hardier than seeds for resisting diseases.

Of course, we have a wide variety of onions and shallot sets in stock for you as always. So, come down and find your perfect onion – you’ll be digging them up before you know it!