University of Vermont Extension System
Department of Plant and Soil Science

Dr. Leonard P. Perry, Extension Professor

• Water: most important cultural factor, amount, quality (see table), temperature, pH 6.5-7.0, may vary with season (5.5-8.5)
• Media: many work, consistency is key, test often; if change, change practices?
• So key, so little used, don’t skimp--use best
• pasteurized
• just moist enough

• Generally sphagnum peat moss vermiculite or perlite (1:1)
• some feel vermiculite stays too wet
• not soil, generally not bark or sand as in production media
• if making own, add lime, P, trace elements, wetting agent

• Many use precharged mix (basic nutrients), if so no fertility first week or two
• nitrate based: tones growth
• ammonia based: quick growth
• specific rates vary with stage, size, plant

• Clean pots, surfaces; 1:9 bleach:water, other products
• Botrytis, damping-off may need preventative sprays/drenches
• Mesh bottom flats/mesh benches--air prune
• Inventory management-- large plug growers, communication: employees, buyers

Wk 1 chamber 70-75°, 80-90%RH

(low light or none, plastic cover alternative)

Wk 2-4 prop house 70-75 °, 70-80%RH

air and soil temperature, may need bottom heat

20-10-20 75ppm, 2x/wk 2; 150ppm 2x/wk 3-4

WK 5-6 harden (?) 60-65 °, 35-40%RH

2:1 Ca and K nitrates, and thereafter as needed

288® 50 sample schedule

• Late May-mid July-- sow , depends on genus, rate of growth, needs
• mid July-late Aug-- transplant to 50s
• Sep 15-Oct 15-- drop temperature from 65 ° to 35 °, over 4-6 weeks, so about 1 ° per day, better and realistically 5 °/wk
• Nov -- sell, or at any stage, or hold overwinter

Wk 2-4 20-10-20, 150ppm

Wk 5-6 15-10-15, 125ppm

Wk7 on no fertility, or as needed

288 sowings vary with growth rate

Slow, sow late May, 8-10 weeks in 50s; Aquilegia hybrids, Campanula carpatica

Moderate, sow mid June, 6-8 weeks in 50s; Lupine, Geum, Gaillardia, Delphinium, Dianthus

Fast, sow mid July, 4-6 weeks in 50s; Achillea, Leucanthemum, Coreopsis, Rudbeckia

72, 125 sample schedule

Aug sow, 65-75 ° 6 weeks

Sep 15-Oct 15 ¯ temps 6 weeks

Nov 35 ° , hold 12 weeks

Feb plant 6-12 weeks

Apr-May sell total 30-36 weeks

sell/buy at any stage, depending

Nursery/grower scheduling options

• as for retailer
• buy early fall
• 288/128® 50s, ¯ temps, vernalize, pot Feb.
• 128 or larger, pot, ¯ temps, vernalize (involves lots more space for overwintering)
• buy late fall as 50s, vernalize, pot Feb.

• 128: 5-6 weeks, 72: 4-5 weeks, 50: 3-4 weeks
• to quart from 50, 128: 4-7 weeks
• to gallon, from128 (3/pot): 10-12 weeks, 72: 8-10 weeks, 50 or larger: 5-8 weeks
• add a 50 or 72 plug, subtract a week or two

• Fertility: 20-10-20 or 15-5-15, once/wk; 200ppm slow growers, 100ppm for fast
• Light: daylength extension for long day (LD) species (forcing into bloom earlier) to 16 hours, incandescent
• Height control

• generally no PGRs (plant growth regulators)
• water less for some species, to initial wilt
• cut back 3 weeks prior to shipping
• less fertility
• DIF for many perennials; night temperature = day temperature (65 ° avg.), sunrise, lower by 5-10° for 2 hours (5am, 5 °)

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.

Last reviewed 12/01