How To Grow Onions and Garlic

Onions are an essential vegetable for all kitchens and can be grown from small immature bulbs, called sets, or from seed. Spring (salad) onions are immature seedlings and are always grown from seed. Garlic is grown from cloves in a similar way.

Soil

A sunny spot with well drained soil is best. When digging over take out any perennial weed roots and improve the organic content by incorporating some Miracle-Gro Gro Your Own Soil Improver. A sprinkling of a general plant food such as Miracle-Gro Gro Your Own Fruit & Vegetable Plant Food will ensure the crop is fed throughout the summer. Rake to a smooth friable surface.

Onion Seeds or Sets

If you are new to grow your own then the small immature onion bulbs, called sets, are the easiest way to get reliable results. Each forms one full-sized bulb. Simply plant at the end of March or beginning of April as detailed below.

The seed route will give you more onions for your money, but good results are more dependent on warm spring weather and the time you have to keep weeds from dominating your crop.

Selecting the varieties to buy

• Onion Sets: All are good croppers including Sturon, Jet Set and Golden Ball. For red onions try Garnet or Red Baron/Emperor.
• Onion Seeds: Ailsa Craig and Bedfordshire Champion are traditional favourites.
• Salad (Spring) Onions: White Lisbon, Eiffel or Ishikuro.
• Garlic: Wight Cristo is said to be a great English variety, but Lautrec Wight is regarded as France’s finest.

Planting Onion Sets

Plant sets in late February or March where they are to mature. Push into the soil, leaving a gap of 10cm (4in) between each set and 20cm (8in) between rows.

Planting Garlic Cloves

Break up bulbs into individual cloves and plant in autumn or early in March. Push into the soil, leaving a gap of 15cm (6in) between each set and 20cm (8in) between rows.

Sowing Onion Seed

When the soil is warm enough (March or April) take out a shallow drill 1cm deep (a drill is a shallow trench that you plant seed in). Sow the seeds thinly and then cover with fine soil and water in.

Thinning

Salad onions don’t normally need thinning, just pull and eat. Onions grown from seed need space to expand so pull out overcrowded seedlings to leave 10cm (4in) between each plant.

Care

Keep weeds under control and water only when the weather is really dry. Keep weeds under control throughout the growing season.

Harvesting

When the foliage start to turn yellow in August/September, lift the bulbs and dry for 7-21 days under cover. Use bulbs/cloves first that are soft, damaged, spotted or have thick necks. The rest can be stored in an airy place in net bags, tights or tied to cord to make an onion rope.

Click here to learn about growing shallots.

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