What is the Viable seed count?

The viable seed count is the number of live seeds contained within any seed product. It indicates how many seeds within that product have the potential to germinate and establish once sown. Usually the viable seed count is shown on a per kg basis, for example if a native seed product contains 55,000 viable seeds per kg and you have purchased 3kg you have 165,000 viable seeds.

What is the difference between a Viable seed count and germination rates?

The germination test only measures the number of seeds which have germinated in a period of time (usually somewhere between 14-60 days), while this test is helpful it doesn’t tell the whole story. Most native seeds have an inbuilt survival trait of seed dormancy which acts to stagger their germination over a long period of time to protect against unseasonal dry spells. Germination tests do not account for seed dormancy so therefore the results for native seeds can be deceiving.

Why is the Viable seed count important for native seeds?

Viable seed counts for native seeds are important for a number of reasons:

1. It allows the purchaser to compare “apples with apples”, native seeds are available in many forms with some species being available in forms ranging from unprocessed harvested florets right through to a pure processed caryopsis (and everything in between). Each different form has vastly different seed counts and price points. The viable seed count of each product allows you to calculate exactly how much live seed you are purchasing and how much it costs.
2. Native seeds also vary greatly in weight and density so calculating sowing rates is very difficult, the viable seed count is a common denominator for which all native seed sow rates can be set. E.g for restoration work you would aim for 500 viable seeds per m2.
3. Knowing the viable seed count also allows for very accurate seed blending. If you require a mix containing roughly 25% of four species, mixing by weight will not achieve an accurate result. Mixing by the number of viable seeds per product is the most accurate way to achieve a successful outcome, as demonstrated by the table below.

To create a seed mix containing the same amount of actual seed of each species you would require vastly different amounts of kgs per species. The table below also calculates how many total viable seeds per kg this mix contains which will allow you to know the appropriate sowing rate.

Make sure you know what your purchasing and ask for the viable seed count. For more information on Viable seed counts or a custom seed mix calculation contact us directly.