RHS Level 2 Certificate

Week 20 – Outdoor food production. Vegetables – perennial vegetables and legumes

Learning outcomes

1. Perennial vegetables1.1 state the place in seasonal rotation of asparagus1.2 state cultivation, propagation and care requirements of asparagus1.3 state 2 pests and 2 diseases of asparagus and their control1.4 state harvesting period and technique and storage2. LegumesFor named varieties of each of peas, french and broad beans state:2.1 state the place in seasonal rotation and successional cropping2.2 state cultivation, propagation and care requirements2.3 state 2 pests and 2 diseases and their control2.4 state harvesting period and technique and storage2.5 explain nitrogen fixing and its importance in crop production

Crop Rotation review

Five main rotation groups (salad crops don’t fit into any of these)

Principle is not to use the same soil for the same group two years running.

One crop can benefit another – brassicas follow legumes.

Intended to keep down build up of pests and diseases that are group specific.

Perennial vegetables - asparagus

Grown from crowns (roots with growing tip) Require good, fertile, well drained soil – a

bed can yield for 20 years so preparation is essential.

Not in a rotation All- male varieties preferred – higher yield Pests – Asparagus beetle, slugs Diseases – Rust, Violet root rot.

Planting Asparagus

Trench 20 -25cm deep and 20cm wide

Crowns spaced at 40cm and planted on a mound of compost or rotted manure with the roots spread out

Ideally fill to about 5cm above the crown initially and then fill in stages as the plant grows

Nitrogen Fixing - review

Bacteria can ‘fix’ nitrogen gas from the air by transforming it into a water soluble organic compound

Rhizobia live in nodules on the roots of legumes. They provide the plant with nitrogen and the plant provides the bacteria with somewhere to live. This is a symbiosis

The nitrogen is released to the soil when the plants roots and green growth decays. So leave the roots in the soil when clearing the legume crop and compost the plants if they are not diseased.

Legumes – general points (1)

With the exception of Broad Beans they are half-hardy so are sown late Spring or earlier under cover.

They need fertile soil but not additional nitrogen. pH 6.5-7.0. Good drainage

Many require support They fix nitrogen so are usually followed by

brassicas in the crop rotation

Legumes – general points (2)

Manure or compost dug in the previous autumn. Prepare a Stale Seed Bed and incorporate a

balanced fertilizer about two weeks before sowing (to allow time for the weeds to germinate).

Sow in single drills at the required spacing and depth or in broad drills as double rows.

Can all be started early spring in pots or root trainers under cover if there are bad problems with mice or flea beetle.

Watering is crucial at flowering and pod set.

Learning Outcomes

. Perennial vegetables1.1 state the place in seasonal rotation of asparagus1.2 state cultivation, propagation and care requirements of asparagus1.3 state 2 pests and 2 diseases of asparagus and their control1.4 state harvesting period and technique and storage2. LegumesFor named varieties of each of peas, french and broad beans state:2.1 state the place in seasonal rotation and successional cropping2.2 state cultivation, propagation and care requirements2.3 state 2 pests and 2 diseases and their control2.4 state harvesting period and technique and storage2.5 explain nitrogen fixing and its importance in crop production