University of Vermont Extension System
Department of Plant and Soil Science

Commercial Ornamental Horticulture (COH) Leaflet 36

Perennials for Spring Sales

Leonard P. Perry, Extension Associate Professor

Perennials should be offerred along with spring bedding plant/annual sales, as customers continue to look for and expect them. In a recent survey of firms selling perennials among other crops (PPA, 1993), perennials accounted for gross sales of 43% for Canadian firms (up 74% from 1992) and 33% (up 27% from 1992) for those in the Northeast U.S.

Pricing should be based not merely on cost, but on perceived value. Standard markups are not the most effective pricing strategy. In a survey of Maine growers (1991), pricing was done by pot size (60% of firms) and also by plant type--age, species (56% of firms).

Depending on species, plants may be forced or allowed to flower naturally.

Guidelines for Spring Forcing of Perennials

Cold: 28F/-3C minimum, 40F/5C maximum, 12 weeks minimum; spring and early summer flowering plants especially, biennials (Dianthus, Digitalis, Lunaria)

Warm: 60-65F/15-17C, 2-6 weeks prior to sale

Daylength: long days (LD) 10 weeks prior to sale, if needed--mainly summer flowering plants; 14-16 hour days or night interruption from incandescent at 2200-0200

Fertility: 50-100ppm N (Nitrate) when cool, 100-200ppm N (any) when warm

*Cold and daylength requirements often vary with species and cultivar (eg. Campanula persicifolia requires cold, no LD while C. carpatica requires LD, no cold)

*Perennials flowering with LD may require cold (eg. Gypsophila, Lysimachia).

*Many LD perennials may flower without cold, although they are more vigorous with cold (eg. Achillea millefolium, Coreopsis, Helenium, Phlox, Physostegia, Platycodon, Rudbeckia 'Goldsturm', Sedum 'Brilliant').

*LD requirement can be replaced by cold for some, eg. Echinops.

*Some perennials may bloom with short days (SD) but also with cold and LD (Aquilegia, Lupinus).

*Some perennials, especially late summer/early fall bloomers (eg. Aster hybrids) may require SD in addition to LD.

Sample seeded perennial forcing schedules, date (week)--for marketing Apr 14 (week 15)

Crop		Sow		Transplant
Aquilegia	Sep 1 (36)	Nov 7 (45)
Arabis Oct 7 (41) Dec 14 (50)
Myosotis Oct 7(41) Dec 1 (49)
Platycodon Feb 7 (5) Mar 7 (9)
Salvia Oct 1 (40) Dec 1 (49)

Local conditions may cause slight deviation from these dates; these are based on sowing in 120 plug trays, transplant from open flats 2-4 weeks earlier.

A Baker's Dozen of Top Naturally Flowering Spring Perennials

Early Spring

Aquilegia canadensis 'Corbett'

Epimedium x versicolor 'Sulphureum'

Polygonatum commutatum

Primula polyantha 'Pacific Giant'

Viola labradorica

Late spring, early summer

Amsonia tabernaemontana

Aruncus aethusifolius

Baptisia australis

Filipendula ulmaria 'Variegata'

Lamium maculatum 'Pink Pewter'

Lamium maculatum 'White Nancy'

Scabiosa columbaria 'Butterfly Blue'

Scabiosa columbaria 'Pink Mist'

Return to Perry's Perennial Commercial Page

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. Lawrence Forcier, Director, UVM Extension System, Burlington, Vermont. University of Vermont Extension System and U.S. Department of Agriculture cooperating, offer education and employment to everyone, without regard to race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status.