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CLOSING DOWN SALE - UK Delivery £1.26

Onion Seeds - Senshyu Yellow

Botanical - Allium cepa


Seed Count:
450 Seeds
Usually despatched within 24 hours
99p, FREE over £15.99
Price £2.28 £1.14 (You save £1.14)

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450 Seeds.

Other Names - Winter Bulbing Onions…

Onion Senshyu Yellow is a reliable and popular overwintering variety normally sown in autumn. It is an extremely hardy onion and will stand well throughout the harshest of winter months as a small young plant and when spring arrives the variety starts to grow vigorously again producing a good sized semi flat bulb with golden yellow skin. If sown in autumn this variety will produce the first early onion bulbs of the season.

  • A very hardy Japanese variety suitable for sowing in autumn to produce the first mature onion bulb the following year.
  • Excellent flavour.
  • An easy winter vegetable to grow.

Suitable For - Vegetable plot, raised beds

Sowing Months - Mid August - early September

Harvest - March - May for salad onions. June - July for bulbs

Gardening is about finding the right balance! Try growing Companion Plants close by to help deter pests.

  • Lettuce and onions grow well together.
  • Chamomile and summer savory - these two herbs if grown nearby are believed to improve the growth and flavour of alliums.
  • Beetroot, Kohl rabi, strawberries and cabbages are good plants to grow close to onions as they do not compete against each another.

Soil Preperation

Add well rotted manure or compost a few months before sowing or planting. Remove any weeds and apply some general purpose fertilizer 1 - 2 weeks before sowing or planting. Before sowing rake the surface when dry to produce a fine tilth.

General InformationSowing & Planting Information
Habit Biennial, grown as an annual Module Grown & Transplants
Type Heritage variety Distance between plants 25 cm
Position Full sun Distance between rows 30 cm
Average height 45 cm Direct Sowing
Average spread 25 cm Sowing distance between plants 1 cm
Hardiness Hardy Distance between rows 30 cm
Overwintering Yes Sowing depth 1 cm
Soil Ph 6.5 - 7.0 Germination temperature 10 to 25℃
    Days to germination 7 - 14 days

Sowing Guide

Early Sowing/Module Sowing

Onions grow well in clumps and will not need to be thinned. Sow 7 - 8 seeds per 4 cm module. As soon as germination starts reduce the heat and move to an area with good daylight exposure. Keep the compost moist but do not overwater. After 3 - 4 weeks plant out. Harden off over a few days before planting out. Plant out at the distance suggested above. Firm the soil around each clump and water well.

Direct Sowing

Sow 1 - 2 seeds every 1 cm at the depth and row distance suggested above. Lightly cover the seeds with fine soil and water well. Thin to 1.5 cm. In spring thin in stages to 10 cm apart, firm the soil again if needed. Thinning's may be large enough to be used as spring onions.

Growing On

Weed often especially in the early stages as the young seedlings resemble blades of grass when young and can very easily be smothered by weeds. Water seedlings well in dry weather. Older plants will need to be watered every 7 - 10 days during dry weather. These plants are hardy and are happy to grow outdoors unprotected over the winter months.


Some of the Japanese onions can be harvested early as spring onions. If growing onions in clumps, to harvest gently twist the largest onion bulb in the clump leaving the rest to grow on some more.
Japanese onions do not store well however the idea behind growing this variety is to bridge the gap between when winter stored onions run out in late spring and when new season bulb onions sown in spring mature in July / August.
These onions can be harvested at any size as salad onions or as bulbs. The remaining bulbs will mature in May / July when their leaves start to turn yellow and fall over. On a dry day carefully lift the remaining bulbs with a fork, once lifted bend the neck of each onion bulb back hard. If dry weather is forecast, lay the onions with their bent necks side by side along the surface of the soil to dry out in the sun.
If however wet weather is forecast after bending the necks remove all of the onions from the garden and dry indoors over 10 - 20 days (longer if the air is humid and cold and the onions are large). Store in a cool dry shed or garage for up to 1 - 2 months. Do not store damaged, bruised or onions showing signs of disease.


Growing a row of onions on either side of carrots can help to confuse and deter the carrot root fly.

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STANDARD DELIVERY - Royal Mail 2nd Class (3 - 5 working days) - £0.95

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Faulty Goods.

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