Asparagus is a low-risk, permanent horticultural crop.
When To Plant
The best time to plant asparagus is when the soil temperatures rise in spring
North Island : mid September to mid October
South Island : from early October
Planting any earlier than recommended may result in death of plants due to diseases associated with wet cold soils or frost damage
Although these recommended planting times are specific to NZ, the same principles apply in other regions.
Asparagus likes deep, well drained soil, free from compaction layers.
Sandy loams, loamy sand or free drained volcanic soils.
Make sure the site is free of perennial weeds before planting
Add plenty of organic matter (well rotted compost, mushroom compost, seaweed), into soil prior to planting.
Asparagus prefers high pH (6.0-6.5)
Lime (dolomite or hydrated lime) and superphosphate should be dug into the soil prior to planting
Spread fertiliser on the soil surface and dig deep to bury the fertiliser to the depth that most root growth will occur i.e. below 15 cm
How To Plant
Open a trench approximately 20 cm deep, with a flat bottom, approximately 20 cm across.
Lay the crowns down one side of the trench, 20 cm apart
Plant another row of crowns along the other side of the trench, but in the gaps of the first row
This gives a staggered double row with 10 plants per m length of row.
Cover the crowns with 5 cm of loose soil. DO NOT fill the trench with soil. This will ensure the crowns get away to a good start
Slowly fill the trench with soil during the following summer and autumn, as you hoe any weeds on the sides of the trench
By the following winter the trench should be filled with soil, and the soil surface flat
Fern Removal In Winter
Once the fern has completely died off and turned brown, cut the dead fern off at ground level
Compost or burn the dead fern
If crowns grow well in the first year, and the spears are 15mm or greater in diameter, these can be picked, but for only 10-14 days maximum. This is a "bonus harvest"
Normally leave plants for two years after planting before harvesting. The first season usually lasts for 3-5 weeks
Year 3 after planting, harvest for 6-8 weeks
Year 4 onwards, harvest for 8-10 weeks
Stop harvesting if the spears get thinner than 10 mm
What To Plant
Plant healthy one year crowns