Broadcast seed sowing, how much seed per area?

Hi all,

Been reading through some previous forum threads (https://permies.com/t/5559/Sepp-Holzer-method-planting , https://permies.com/t/1998/Sepp-Holzer-seed-mix , https://permies.com/t/45183/Throwing-seeds-top-soil), I'm thinking of having a go at broadcast sowing on my small allotment garden (150sqm) next season as I don't have much time to be down there. I've been reading about seed mixes, mainly Sepp's approach I think its more something you can only get the hang of through a bit of trail and error to what you think suits your land so its not really a question about that.

The question is, is there any tips or guidelines people can share with what rate people who have experimented with this approach generally sow per square metre? Obviously different seed sizes require different sowing rates, do you try to sow thickly, for a higher success rate? or thinly to avoid too much competition?

I know that is you are sowing a wildflower meadow mix for example it is generally sown at a rate of 1.5g per sqm, is this a good comparison to be thinking of here as a beginner to broadcast sowing? as I guess I am in a lot of ways mimicking a wildflower mix in that I am having a variety of niches filled by the variety of species I will be using.

It's so incredibly variable that I literally don't know the rate until I'm standing there doing it. Time of year, soil moisture, weather, bird migrations... I have to see it to know.

One method might be this: for everything in your mix determine what is the normal, optimal sowing rate. E.g. Hairy vetch is usually 30-40lb per acre (you can calculate from there). That is the minimum, and you should increase from there depending on conditions. I over-sow cover usually 25% at a minimum but I do not use Sepp Holzer methods because I really cannot afford to be feeding birds. In such a small area you can always thin out so I would not worry about it being too crowded.