Alliums

Question 1

Sowing

Leeks

Answer 1

Sow in seed bed.
2cm deep, 3cm apart
Transplant when 20cm high; make a hole 15cm deep, 30 cm apart and drop leek in.
Sow under glass in Feb for early crop, plant out in May.
Sow outside mid Mar to mid April
Transplant June/July
Ground occupancy 35 to 45 weeks

Question 2

Special requirements

Leeks

Answer 2

Draw up the soil around the stem to keep it blanched.

Question 3

Harvesting

Leeks

Answer 3

Harvest Oct to mid March
Harvest when young
Storage - can be left in ground until needed or frozen.

Question 4

Onions

Varieties

Answer 4

Ailsa Craig
Red Ray
Lisbon

Question 5

Sowing onions

Answer 5

Sow in situ 1-2cm deep in drills 30cm apart (bulb varieties)
For earlier crop seed can be sown under glass in Jan/Feb and transplanted in April.
Sown in August and over wintered to provide earlier crop.

Question 6

Plantin onion sets (immature onion bulbs)

Answer 6

Plant mid Feb to mid April
5-10cm apart
Drills 30cm apart
Plant so that nose of bulb is just visible
Ground occupancy 25 weeks (spring sown) or 45 weeks (over wintered)

Question 7

Harvesting onions

Answer 7

Bulbs can be pulled for immediate use at anytime.

When bulbs are mature foliage will wilt. They can be left for two weeks before lifting.

Question 8

Storage of onions

Answer 8

Hung on string to dry.

Sliced and frozen

Question 9

Onion pest

Answer 9

Onion Fly
Foliage turns yellow and wilts
Young plants may die
Roots and stems are tunnelled
Treatment - flies are attracted to newly disturbed soil - sow seed in stale bed prepared 10 day earlier.
Cover seed with fine net.
Biological control of mixture of nematodes.

Question 10

Disease

Onions

Answer 10

White Rot
Fungal disease survives in soil for many years.
Can move through soil to infect new plants.
Symptoms - foliage turns yellow and wilts, White mould containing small black bodies appears at the base of the bulb.
Treatment - dig up and burn infected plants.

Question 11

Alliums
General information
Seeds and sets

Answer 11

Can be grown from seed or onion and shallots can be grown from immature bulbs (sets).
Advantages of sets: more successful in cold areas, tolerate poorer soils, reach maturity quicker, not attacked by onion fly.

Question 12

Alliums general

Soil requirements and weed control

Answer 12

Grow best in a fertile, well drained soil - compost should be added in previous autumn.
pH 6.5 - 7.00 lime if necessary.
Weed control is important - lack of above ground growth means weeds aren’t suppressed.