While uncertified tree and shrub plant material (i.e. from sites in Ireland not listed in the National Catalogue of Seed Stands) is available on the Irish market, studies to date have indicated that the use of this material is inappropriate in terms of best practice.
There is also the potential for foreign provenance plant material to pollute the native tree and shrub gene pool as a result of planting of non-certified and foreign provenance (e.g. UK. Dutch, Hungarian origin) plant material as part of landscape design plans (references).
Studies to date which have examined the genetics of plants from non-certified seed sources in the Irish landscape e.g. Kelleher et al. (2003) found that the majority of oak trees from woodlands surveyed in the study across Ireland were of foreign provenance (refer to Kelleher et al, 2003). Clarke et al. 2000 and 2003 examined hedgerows in Northern Ireland and found that only one of the fifteen hedgerows selected for surveying in the study was representative of an Irish genotype.
In this regard, sourcing plant material from non-certified sources in Ireland may be comparable to utilising foreign provenance plant material and may result in similar impacts as would the importation and use of plant material from the UK, the Holland and elsewhere in mainland Europe.