How To Sow & Grow Onions

Large Onion & Pickling Onion Varieties

Growing From Seed
To produce the largest onions from seed an early sowing under protection is essential. Sowings can be made as early as December, and for many people Christmas Day afternoon remains the traditional sowing time.

Here at Victoriana we tend to sow our onions in the first two weeks of January, though sowings up to early March will produce very satisfactory results indeed. In fact sowings as late as late April / early May will still produce a worthwhile crop, they will just not be as large.

• Sow seed thinly onto the surface of lightly firmed trays of fresh seed compost.
• Cover the seed with a thin layer of fresh seed compost to 'just cover' and lightly firm down. Do not cover too deeply otherwise the seed will fail to germinate.
• Water the trays thoroughly and germinate under protection at a temperature of 50° – 60°F (10° – 16°C).
• Once germinated grow on under protection at a temperature of 50°F + (10°C +).
• When the weather warms up harden off the seedlings before planting out (see guidance below) by gently 'tearing' the young plants in the tray apart.

In the alternative direct sow into prepared ground outside from late March until July.

• Sow thinly in drills ¾" (2cm) deep in rows 12" (30 cm) apart.
• For larger onion varieties thin to 9" (23 cm) apart when large enough to handle.
• For pickling and smaller onion varieties thin to 4" (10 cm) apart when large enough to handle.

Growing From Young Plants
Set out late March onwards (the later planting out is left the smaller the resulting onions will be, though worthwhile crops can still be produced from plantings as late as early July).

• For larger onion varieties set out 9" (23cm) apart in rows 15" (37.5 cm) apart.
• For pickling and smaller onion varieties set out 4" (10 cm) apart in rows 12" (30 cm) apart.

Top Tips

• Onions grow well on most soils but perform best on lighter soils. They prefer a full sun position but will tolerate partial shade.
• Ensure plants are watered regularly but avoid over watering as this can both slow their development and reduce their keeping qualities.

Harvesting
Smaller and pickling onions will be ready for harvest July – September (dependant on sowing time). Larger Onions will be ready for harvest late August – late September, when the top growth starts to bend and die down.

• Carefully lift the onions using a hand fork or similar and, if the weather is dry and sunny, leave the onions to dry on the ground. If you are lifting in damp or wet weather dry the onions indoors or in your greenhouse on racking or shelving.
• Store onions in cool well ventilated conditions either tied and hung in plaits or as single layers in trays.

Salad & Spring Onions

• Sow thinly in drills ¾" (2 cm) deep in rows 12" apart from mid March (weather permitting) until early September.
• Thin to approximately ½" (1 cm) apart when large enough to handle (and of course eat the thinnings!)
• Harvest when they have reached your desired size; the longer they are left in the ground the larger they will become. Use immediately though they will keep in the fridge for a few days.

• Top Tips
• Protect early or late crops from frost with cloches or similar.
• Onions grow well on most soils but perform best on lighter soils. They prefer a full sun position but will tolerate partial shade.
• Keep the crop watered in dry spells as this will avoid the onions becoming too bulbous.

Siberian Everlasting Onions

• Sow thinly in drills ¾" (2 cm) deep in rows 15" apart from mid March (weather permitting) until early September.
• Harvest and use immediately when they have reached your desired size, thinning the row as you go; the longer they are left in the ground the larger they will become.
• Always ensure you do not clear all the plants from a row as this will allow them to clump up and regenerate.
• As these are Winter hardy these can be 'kept going' from Season to Season.