Treatment with dormancy breaking plant hormones

Deeply dormant species, such as Trollius, can be made to germinate reliably by soaking in gibberelic acid, or in combination with other treatments, for example leaching (Hitchmough et al. 2000). Whilst this is essentially kitchen-level science, it is probably

Table 6.12. Typical percentage field establishment of prairie, wet meadow and dry meadow species given adequate pre-treatment (where necessary) to break dormancy and sown under ideal soil moisture conditions. Data derived from author’s experiments

Low to very low field establishment (<10%)

Medium field establishment (10-30%)

High to very high field establishment (30-50%)

Prairie species

Prairie species

Prairie species

Aster laevis

Aster oolentangiensis

Aster novae-angliae

Solidago ohioensis

Baptisia australis

Echinacea pallida

Sporobolus heterolepis

Coreopsis lanceolata

Echinacea purpurea

Veronicastrum virginicum

Helianthus mollis

Monarda fistulosa

Liatris aspera

Ratibida pinnata

Damp/wet meadow species

Liatris pycnostachya

Solidago rigida

Aconitum napellus

Rudbeckia subtomentosa

Campanula lactiflora

Schizachyrium scoparium

Damp/wet meadow species

Primula denticulata

Silphium

Lychnis chalcedonica

Primula florindae

Solidago speciosa

Polemonium caeruleum

Stachys officinalis

Sorghastrum nutans

Primula vulgaris

Succisa pratensis

Ranunculus acris*

Damp/wet meadow species

Rumex acetosa

Astrantia major Thalictrum aquilegifolium

Sanguisorba officinalis

Trollius europaeus

Dry meadow species

Buphthalmum salicifolium

Dry meadow species

Daucus carota

Centaurea scabiosa

Dianthus carthusianorum

Hieracium aurantiacum

Lychnis coronaria

Malva moschata

Primula veris

* When sown in winter.

Origanum vulgare Papaver orientale

Salvia nemorosa

too complex for use in practice. Jelitto Seeds offers chemically treated seed (Jelitto GoldNugget Seed®) of a wide range of deeply dormant or erratic nondormant species. This is more expensive than dry seed but gives very predictable results.

Germination requirements of a wide range of herbaceous plants are given in the Jelitto Seed Catalogue (Jelitto 2002), although, in some cases, germination is more erratic in field sowing than indicated, as recommendations are based on germination under controlled nursery conditions.