Site selection and soils
The plants and plant communities which grow on a site are to a large extent governed by the characteristics and location of the site and soil in which they are rooted. Plant species have evolved strategies to exploit different combinations of climate, soil conditions and disturbance by animals or man: some species have specialised to thrive in particular conditions such as occur on chalk soils, other species are more generalist. For any set of conditions there will be species that thrive and survive, and others which do less well or fail; through this process a natural balance between species is established. Recognising and understanding the characteristics of your site and soil is clearly useful in deciding which species are most likely to do well.
Work with nature: The most rewarding approach to using wild seeds is to work with nature. If you aim to sow a selection of species that are naturally suited to your soil and site conditions, and if you manage the resulting plant community sympathetically allowing natural selection to determine the balance of species appropriate to your site, you have the best chance of attaining the maximum potential from your site and with the least effort. The alternative gardening approach by comparison requires a struggle for control with nature to impose a specific idea of aesthetic and balance that may have no basis in nature.
Plant assessment: Much can be learnt from looking at the plants already growing on site or on similar soils and situations in the locality. A preliminary assessment of local vegetation should be undertaken at an early stage to establish what type of plant communities and approaches are likely to be suitable, as well as identifying any pre-existing habitat or plants that ought to be retained and conserved.
Soils and fertility: Of the factors that influence plant community development, soil characteristics and in particular the fertility and acidity of the soil are probably the most fundamental from the point of view of specifying and using wild seeds. The reason for this is that there is a generally observed principle that the most productive fertile sites and soils tend to have the least potential for plant diversity, whether open grassland, woodland or wetland. Changes in light or water levels will change the type but not necessarily the number of plant species that grow well, but increases in the nutrient status of a site (such as the addition of fertiliser to flower-rich grassland) leads directly to a loss of diversity as the additional resources fuel the growth of the most competitive components at the expense of others. For this reason the emphasis in the following notes will be biased to a discussion of soils and their importance to wild flower seeding.
Understand site potential and limitations: Unfortunately whilst all sites are capable of supporting a naturally balanced plant community, not all sites have the same potential for supporting a diversity of plants, or an attractive range of plants. Where a choice of soil or location is available or can be engineered by earthmoving and land forming (eg in road building) it is useful to be able to identify or specify the most suitable.
Where the choice of soil and location is fixed then understanding the potential or limitations of the site will inform expectations as to the results that can be achieved and the effort required. This may include a decision as to how suitable or cost effective the site is with regard to the desired outcome.