A very popular and reliable variety for well over 100 years, Onion 'Density 4' is ideally suited to our climate producing medium to large, globe shaped, straw coloured bulbs with pure white flesh and a good flavour.
A long day variety that can be sown from Autumn through to Spring, and harvested in August. As a standard maincrop it offers excellent quality, high yields and a very good storage life: It is ideal for extended storage as the neck of the bulbs is filled. From an August harvest, they will store well throughout winter until March.
Few vegetables have more uses in the kitchen or are in such constant demand than onions. Nowadays we can obtain onions fresh from the garden or out of store almost all year round from just a couple of carefully-timed sowings.
When the bulbs start to fatten up, you can begin harvesting individual onions as needed. In late summer or early autumn, the leaves on your onion plants will start to flop over. This happens at the ‘neck’ of the onion and it signals that the plant has stopped growing and is ready for storage. All the remaining onions should be harvested soon thereafter. Suitable for long-term storage, from an August harvest, they will store well throughout winter until spring.
Choose an open, sunny site with good drainage which has preferably been dug and manured in the previous autumn. Do not plant or sow on freshly manured bed. Lime if the soil is acid. Avoid planting in an area where the previous crop was of the onion family. Many exhibitors grow their show onions in a permanent bed in order to build up fertility, but in the kitchen plot it is a much better idea to change the site annually.
Apply a general fertilizer if needed and rake the surface when the soil is reasonably dry. Tread over the area and then rake again to produce a fine, even tilth.
Timing: Sow in autumn or sow in late winter to spring
Seeds can be sown direct in autumn to be harvested in 46 weeks to produce large bulbs (not advisable in very cold areas) Otherwise sow in February under cloches or direct March to April and harvest in 22 weeks. In cold areas and for exhibition bulbs sow under glass in January, harden off in March and transplant outdoors in April.
Sow very thinly in 1.2cm (½in) deep drills, leaving about 25 to 30 cm (10 to 12in) between rows. Water very gently if the soil is dry, and cover with soil.
When large enough to handle, thin the crop in two stages. Close spacing will give smaller onions than wider spacings. Lift the seedlings carefully – the soil should be moist and all thinnings removed to deter onion fly. (They may be used as spring onions)
Thin spring-sown seedlings first to 2.5cm (1in) then when the seedlings have straightened up to 5 to 10 cm (2 to 4in) apart.
Thin autumn sown onion seedlings to about 2.5cm (1 inch) in the autumn. Further thin to about 5 to 10 cm (2 to 4 in) between plants in the Spring.
Seedlings raised under glass should be transplanted 4in (10cm) apart, leaving 9in (23cm) between the rows. The roots must fall vertically in the planting hole and the bulb base should be about 1cm (½in) below the surface. Plant firmly.
Hoe carefully or weed by hand – dense weed growth will seriously affect yield. Water if the weather is dry (not otherwise) and feed occasionally. Feed an autumn-sown crop in March. Mulching is useful for cutting down the need for water and for suppressing weeds. Break off any flower stems which appear. Stop watering once the onions have swollen and pull back the covering earth or mulch to expose the bulb surface to the sun.
When the bulb is mature the foliage turns yellow and topples over. (Some gardeners bend over the tops as the leaves start to yellow). Leave them for about 2 weeks and then carefully lift with a fork on a dry day.
Inspect the bulbs carefully – all damaged, soft, spotted and thick-necked onions should be set aside for immediate use in the kitchen or for freezing. The rest can be stored and will need to be thoroughly dried. Spread out the bulbs on sacking or in trays, outdoors if the weather is warm and sunny. Drying will take 7 to 21 days, depending on the size of the bulbs and the air temperature.
Avoid storing whole onions in the refrigerator, which has a damp environment. Do not store onions next to potatoes. Both potatoes and onions emit a gas which causes them both to sprout and spoil faster.
Store the whole onions in a dry place, in an area where there is good air circulation. They should also be stored in a cool, dark area to prevent them from sprouting and rotting too soon as a result of light and humidity. Store the onions in trays, net bags, tights or tie to a length of cord as onion ropes and they will keep until late spring.
The the skin of a white onion will give shades of orange while the skin of the red onion can be used to create a medium green, slightly lighter than forest green.
How to slice an onion without crying:
Freeze the onion for ten minutes before cutting. The sulphuric compound that leads to tears will not react as quickly when it’s cold. If you forget, just light a candle, as a burning flame can burn away the sulphuric fumes.
If you have just painted a room and the fumes are a little overwhelming, slice an onion in half and place it in a bucket of cold water. Leave the bucket in the room overnight. The fumes will magically dissapear (or a least be reduced a fair bit).
Prior to Linnaean taxonomy the Onion family was spread over four genera. The bulb Onion, Shallot and Welsh Onion were found in the Cepa genera. Garlic was placed in the Allium genera, Leeks were listed as Porrum and the Chive was classed as Schoenoprasum, its current species name.
The genus name, Allium comes from the Celtic All, meaning 'pungent', the species name cepa, is from the Roman cepae, meaning 'onion'.
The common name of onion seems to come from the Latin Unio or one, signifying that the bulb is of one unit.
The traditional way of storing onions is to string them together and hang them up. It is quite easy to do, it stores them perfectly, they are easy to access and it looks fantastic!
The key to keeping them secure is to use a “upside down figure of eight” so that the weight of the onion bulb is on top of the dried stem.
- Ensure that the onions have been left to dry and ripen but still have pliable stems. Remove any loose outer skins and trim off the roots. If necessary cut the stem to about 10cm (4in).
- The length of the string is not really important but remember that the more onions that you place in the string the heavier it will be - and you will have to lift it, to hang it up. A length of string about 1.6m (5ft) long is about right. Fold the string in half and tie a knot at the loose ends to fasten them together.
- To make working a bit easier, hang the string on the back of a door using a hook or bent out of a piece of wire coat hanger or whatever is convenient to give a suitable working height.
- Twist and form a loop in the bottom end of the string and place the neck of an onion in the loop. Tighten the loop around the neck. You will find that the onions own weight is sufficient to hold it in place. Cut off any excess stem to leave about 2cm (1in).
- Add a second onion by weaving the stem around the string as in the picture above - using a “upside down figure of eight”. Push the stem downwards and trim off any excess stem, leaving about 2cm (1in). The third onion is woven in from the opposite side of the string in the same way. As you push each onion down it will lock the previous onion in place.
- Continue adding onions from alternate sides until you reach the desired length. Stop when you have a comfortable weight to carry. If you have too much string left at the end, simple knot it at the required length to form a smaller loop and cut off the excess.
- Hang in a cool dry place to store - or hang them on your bicycle bars and ride round town!
- Additional Information
Packet Size 2.5gms Average Seed Count 800 Seeds Common Name Maincrop, White Bulbing Onion Family Alliaceae Genus Allium Species cepa Cultivar Rijnsburger Hardiness Hardy Biennial Spacing Thin to about 5 to 10 cm (2 to 4 inches) Position Choose an open, sunny site with good drainage which has preferably been dug and manured in the previous autumn. Time to Sow Sow in Autumn or Late Winter to Spring Germination 21 days Time to Harvest Autumn-sown - 46 weeks, Spring-sown - 22 Weeks Notes Stored seed viability: 1-2 years. Yield from a 10 ft row: 4kg (8lb). Stored seed viability: 1-2 years.