RHS Level 2 Certificate

Week 19 – Outdoor food production. Vegetables – crop rotation, intercropping and successional cropping

Learning outcomes

A. Identify three active revision techniques1. Cultivation techniques (2)1.1 Describe the methods used to advance and extend the productive

season of outdoor food crops.1.2 Identify a range of propagation methods used in the production of a

range of outdoor food crops.2. Crop rotation etc2.1 State the benefits and limitations of using crop rotation.2.2 Describe how crop rotation can be used in the vegetable garden.2.3 Describe two methods by which successional cropping can be

achieved in the production of a range of vegetable crops.2.4 Define the term: ‘intercropping’.2.5 Explain how intercropping can be used to maximise production.

Exam preparation - introduction

Registration – complete form, fee £40, to be returned ASAP

Revision – how to get started? Revision planning – ‘if you fail to plan, you

plan to fail’ Revision techniques – reading, remembering

and ‘doing’. The more active your approach the more you will remember.

Revision – getting started

Make a plan of the time you have available – do what you can. If you only have half an hour then study for half an hour.

Plan how you will cover the material – aim for three reviews of each topic

Just reading the material is not effective – you need to work with the information (writing it in your own words, teaching someone else, making mind maps or flash cards, writing answers to past exam papers) to revise effectively.

Extending the season for food crops

Using protection – cloches, greenhouse, poly-tunnel - at the beginning and end of the season.

Using varieties that are suited to the stage of the growing season. For example Peas (Pisum sativum) can be picked from May to September if the right varieties are chosen.

Sow in succession – so that there are new plants ready to harvest as one batch finishes.

Propagation methods for vegetables

Seed – sown outside or sown in pots under cover Plants – young vegetable plants at planting out stage

can be purchased from mail order suppliers who will deliver in the correct week for planting.

Roots, slips and sets – Asparagus (Asparagus officinalis) is supplied as a root, Sweet potatoes (Ipomoea batatas) as slips (shoots with part of the root tuber – a bit like propagating Dahlia) and onions (Allium sativum) as sets (juvenile bulbs).

Intercropping and other intensive cropping approaches

Intercropping – growing rows or plants of a quickly maturing vegetable between those of a slow growing one.

Catch cropping – growing a quickly maturing crop on soil left vacant by a harvested crop or set aside to be planted later.

Mixed cropping – growing several vegetables together that benefit each other and are harvested at the same time (e.g. ’the Three Sisters’: sweet corn, beans and squash).

Crop rotation

Vegetables divided into five groups – permanent planting (perennials like Asparagus); Brassicas; Legumes; Alliums; root crops.

Salad crops and some others like Sweet Corn do not fall into a rotation group

The principle is not to grow the same group on the same soil two years running.

Crop Rotation – benefits and limitations

Benefits Limitations

Minimises plant problems – pests, diseases and deficiencies

Most pests and diseases are mobile or have long persistence

One crop can benefit the next in the rotation – nitrogen fixing legumes; potatoes suppress weeds

Personal taste is vital on a small scale – the grower might like brassicas but not carrots.

Planning the rotation also enables planning succession

Inflexible – intercropping, catch cropping or mixed cropping do not fit well

Successional cropping

Sowing different varieties – early, mid-season and late

Sowing a few seeds at regular intervals so that the plants do not all reach maturity at the same time. For example, hearting lettuce (such as Cos) take 8 -14 weeks to reach maturity. Sowing half a row each week-10 days from late March until late July gives continuity of harvest May to October.

Learning outcomes

1. Cultivation techniques (2)1.1 Describe the methods used to advance and extend the productive

season of outdoor food crops.1.2 Identify a range of propagation methods used in the production of a

range of outdoor food crops.2. Crop rotation etc2.1 State the benefits and limitations of using crop rotation.2.2 Describe how crop rotation can be used in the vegetable garden.2.3 Describe two methods by which successional cropping can be

achieved in the production of a range of vegetable crops.2.4 Define the term: ‘intercropping’.2.5 Explain how intercropping can be used to maximise production.