Botanical name : Atriplex hortensis
Common name : Orach, Mountain spinach
Intermediate difficulty for seed saving
Lifecycle: Annual
Pollination: Wind pollinated
Mating system: Monoecious with separate pollen producing and accepting flowers on the same plant. Self-compatible.
Suggested spacing: Spacing needs to be large enough for a mature plant. 45cm
Seed specific requirements: None
Isolation distance: 250 m
Population size: 5 or more plants
Seed maturity: Seeds are mature when their covering has become papery and brown
Processing method: Dry thresh and winnow
Expected seed viability: 2 years
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Growing for seed
Orach may be grown for eating like spinach using quite close spacings and being eaten while leaves are young and small. But when grown as a seed crop the plants need much larger spacings and preferably not harvested at all for eating so that they can mature into large, strong plants.
Orach is wind pollinated and seed crops need to be kept at least 250 m from other varieties of flowering orach in order to avoid unwanted crossing. Orach is self-fertile and so seed can be collected from just a single flowering plant. But better genetic stability for long term maintenance of the variety requires 5 or more plants being allowed to flower together.
Flowering stalks can reach 2 metres and may require staking and tying up on very windy sites. Although they are usually quite robust plants side branches can break away from the main stem.
There are three types of flowers on an orach plant. The pollen producing ones, and two types of pollen accepting flowers – one which develops into seeds with papery coverings and one which develops into a dark bare seed.
Selection
Selection is based on plant vigour and leaf size and colour.
Harvest
Orach plants flower and mature abundant amounts of seed over weeks so it can be difficult to determine when best to harvest. Seed is mature when the bracts turn brown and dry. Branches can be cut when approximately 60% of the seeds on that branch are mature.
Processing
Cut stems should be dried for a few weeks before processing.
Orach can be difficult to winnow as the papery capsules are quite light and can be blown away easily. It can be easier to try and avoid winnowing by being careful to only strip the seeds off the stems when running a gloved had along them. Appropriately sized sieves or mesh can be used to remove most of the larger unwanted plant material.
Note that the different flower types produce different seed types. Orach produces seed with papery bracts and bare black seeds. This is likely a survival strategy. The bare seeds will drop around the mother plant whereas the bracted seeds will be more prone to distribution via the wind. The black seeds take longer to germinate.
Contributors
Liz Worth, Nellie Pryke