1. Basics of Forced Flowering Perennials Royal D. Heins Oro Farms

2. What information do you need to produce flowering perennials? Green or in flower Space availability and when Acceptable input costs Pot size Facility availability

3. Equipment needed to produce perennials Heated greenhouse Long-day lighting Photosynthetic lighting Short-day environment Cooler Late source of plants

9. Let’s talk about perennials, then come back and identify the best plants for the situations and what is needed to force out of natural season.

10. 1 st Year Subsequent Years Emergence DormancyFlowering Vernalization Winter FallSummer Long Days Spring Winter Spring / Summer Seed Germination DormancyJuvenile Growth Maturity Vernalization Fall Short Days Cooler temps. Herbaceous perennial life cycle

11. Flowering Mechanisms Juvenile plant Mature plant Flower Warm temps. Flower Cold required Warm temps. Cold required required Long days Flower Warm temps. required Long days Flower Warm temps.

12. Horticultural Perennial Flowering Schedules SummerFallWinterSpringSummer FallWinterSpringSummer Plant Grow to Flower VernalizeGrow to Flower PlantBulk PlantBulk In the field

13. Plant Material from Plugs Plant to finish pot Force to Flower Bulking Vernalization Seed Vernalization Bulking Germination Force to Flower Plant JuvenilityJuvenility Vegetative Cutting Vernalization Bulking Rooting Force to Flower Plant

14. Plant Material from Bareroot Clumps PropaguleSeedRooted Cutting or Division Bulk during summer Force to flower Plant to field Dig from field Vernalize in cooler Plant during winter or early spring Plant to finish pot Bulk Vernalize Force to flower

15. Keys to Success Mature plants Proper plant size Proper cold treatment Proper photoperiod Proper timing Adequate light

16. Keys to Success Mature plants – plants not juvenile

17. Juvenility – Usually refers to seed-propagated plants – This is a period where plants will not flower even if given appropriate environments – A plant must reach maturity to flower

18. Not by the size of the plug tray in which it was produced… How Can You Tell if an Herbaceous Perennial is Mature?

19. ___________________________________________________ How Can You Tell if an Herbaceous Perennial is Mature? Plant leaf number is the key.

20. ___________________________________________________

22. Plug size by itself does not provide the answer. But, older plants in larger plug trays have a higher potential to be mature.

23. ___________________________________________________ Age Requirements for Flowering Common Herbaceous Perennials Aquilegia Columbine Some species require at least 15 leaves to flower consistently Aster alpinus Alpine aster Plants require at least 15 leaves to flower consistently Astilbe arendsii Astilbe Plants with five to six leaves flowered very inconsistently Coreopsis ‘Sunray’ Tickseed Juvenile phase ends with about 16 leaves Echinacea purpurea Coneflower Plants with four leaves flower Euphorbia epithymoides Cushion spurge Plants with six to eight leaves failed to flower Goniolimon tatarica Statice Plants with 10 to 14 leaves failed to flower Heuchera sanguinea Coral bells Plants require 16 leaves to flower consistently Physostegia virginiana Obedient plant Plants require at least 10 leaves to flower consistently Veronica spicata ‘Blue’ Speedwell Plants with six to eight leaves will flower Plant nameCommon name Age requirements

24. Lack of flowering may be caused by juvenility or lack of adequate vernalization

25. Keys to Success Mature plants Proper plant size

26. ___________________________________________________ Considerations Container size for finished product Planting date (time to bulk before flower induction)

27. Horticultural Perennial Flowering Schedules SummerFallWinterSpringSummer FallWinterSpringSummer Plant Grow to Flower VernalizeGrow to Flower PlantBulk PlantBulk In the field

28. ___________________________________________________ Available Plant Sizes Plug trays – 512-cell – 288-cell – 128-cell – 72-cell – 50-cell – 36-cell 2-1/4 inch pots Field grown, bare-root divisions or clumps Previous year Current year

29. ___________________________________________________ Starting Material Influences Flowering percentage (if plant has a juvenile phase) Plant size at flowering Flower number Time to flower

30. ___________________________________________________ Starting Plant Sizes

31. ___________________________________________________ Influence of Starting Size on Subsequent Flowering of Plants

33. ___________________________________________________ Starting Material Disease free

34. Artemisia ‘Silver Mound’

35. Echinacea

36. ___________________________________________________ Starting Material Disease free Uniform development

37. Phlox paniculata

38. Aquilegia

39. ___________________________________________________ Starting Material Disease free Uniform development Multiple eyes (buds)

40. Multiple buds produce a full pot

41. More lateral buds will yield more shoots to fill the pot

43. ___________________________________________________ Points to Remember Determine final container size Select starting material that is an appropriate size based on the planting date The larger the starting plant material and the earlier the plant is potted, the larger the finish plant

44. ___________________________________________________ Points to Remember To produce large plants – Bulk small plants before flower induction – Plant multiple small plugs into one large pot – Start with large plant material with multiple shoots

45. Keys to Success Mature plants Proper plant size Proper cold treatment

46. Flowering Mechanisms Juvenile plant Mature plant Flower Warm temps. Flower Cold required Warm temps. Cold required required Long days Flower Warm temps. required Long days Flower Warm temps.

47. ___________________________________________________ Responses to Cold Treatment Cold treatment not recommended

48. ___________________________________________________ Cold Treatment Not Recommended

49. ___________________________________________________ Cold Treatment Not Recommended

50. ___________________________________________________ Responses to Cold Treatment Cold treatment not recommended No response to cold treatment

51. ___________________________________________________ No Response to Cold Treatment No cold15-weeks cold

52. ___________________________________________________ Responses to Cold Treatment Cold treatment not recommended No response to cold treatment Cold treatment beneficial – Increased flowering percentage – Decreased time to flower – Increased flower number – Improve flower uniformity

53. ___________________________________________________ Cold Treatment Beneficial No cold15-weeks cold

54. ___________________________________________________ Responses to Cold Treatment Cold treatment not recommended No response to cold treatment Cold treatment beneficial Cold treatment required

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58. Delivering Cold Treatment Cool seedlings or cuttings in the plug tray – Plants that are mature, not juvenile Pot in larger container, grow until mature and then place in a cooler or cold greenhouse – Species with a juvenile phase – Plants that do not have the minimum recommended number of leaves

59. ___________________________________________________ Delivering Cold Treatment In a cooler – Nine-hour photoperiod – Lights delivering about 50 footcandles In a greenhouse Under a thermal blanket outdoors Purchase plugs that have been cooled

60. Overwintering and cooling outside

61. Overwintering view of 2-gallon pots

62. Production greenhouse overwintering perennials

63. Hosta overwintered

64. ___________________________________________________ Delivering Cold Treatment Forcing Perennials for Sale in Flower _________________________________________________________

68. Plant appearance after cooling can be “ugly”

69. ___________________________________________________ Effective Temperatures Range from 32°F (0°C) to 45°F (7°C) 41°F (5°C) is recommended Temperatures below freezing can be used but, Avoid temperatures below 28°F (-2°C)

70. ___________________________________________________ Duration Varies by species Most species will flower properly following 6- weeks cold, but some may require up to 10 weeks of cold.

71. Keys to Success Mature plants Proper plant size Proper cold treatment Proper photoperiod

72. 1 st Year Subsequent Years Emergence DormancyFlowering Vernalization Winter FallSummer Long Days Spring Winter Spring / Summer Seed Germination DormancyJuvenile Growth Maturity Vernalization Fall Short Days Cooler temps. Herbaceous perennial life cycle

73. ___________________________________________________ Changes in Natural Photoperiod Variations in day length for different latitudes in the Northern Hemisphere

74. ___________________________________________________ Types of Photoperiod Responses Day-neutral plants (DNP) Short-day plants (SDP) Long-day plants (LDP)

75. ___________________________________________________ Perennials in Northern Climates DNP = no response to long days (generally only after cold) Facultative LDP = long days beneficial Obligate LDP = long days required

77. ___________________________________________________ Day-Neutral Plant

78. ___________________________________________________ Facultative Long-Day Plant

79. ___________________________________________________ Obligate Long-Day Plant

80. Obligate long-day plant

83. Rudbeckia showing short day growth habit

84. Echinacea with short day growth habit

85. Echinacea growing with LD

86. ___________________________________________________ Lighting Strategies Night interruption (NI) Predawn lighting Day-extension lighting

87. ___________________________________________________ Response of Coreopsis ‘Early Sunrise’ to Long- day lighting treatments

88. ___________________________________________________ Effectiveness of Night Interruption Treatments on Campanula carpatica

89. ___________________________________________________ Sensitivity of Campanula carpatica to Low Light Levels 0 0.25 0.5 5 10 footcandles

90. Comparison of commonly used electric light source in R/FR Light sourceR/FR Sunlight1.15 High pressure sodium5.9 Incandescent0.7 Metal halide3.3 Cool white fluorescent8.8 Light Quality Is Influenced by Light Source

91. ___________________________________________________ Influence of Light Quality on Coreopsis grandiflora

92. Types of Photoperiodic Lighting Incandescent Fluorescent High Pressure Sodium Moving High Pressure Sodium

93. Incandescent BenchLampsSpacing Height 4 foot60W 4 feet 2 to 3 feet 2-4 feet100W 6 feet 2 to 3 feet General rule - 1.25 Watts per square foot

94. Incandescent Installation at Post Garden’s in Rockwood, MI u 500-watt quartz lamps u 96 lamps per acre u 15’ between lamps u Rows of lamps spaced 60’ apart u Lamps face both directions in each row u Equals 1.1 W per square foot

96. 36’ 15 60’

97. Incandescent Installation at Yoders - Alva, Florida u 150 watt bulbs with internal reflector u 10’ x 10’ spacing u 8’ to 9’ above soil u Equals 1.5 W per square foot while on u 5 minutes on/5 minutes off for 4 hours u Equals 0.75 W per square foot continuous duty

99. Fluorescent Installation at Yoders - Pendleton, South Carolina u 75-watt CWF, 8’ tube u 10.5’ x 10.5’ spacing u 8’ to 9’ above benches u Equals 0.75 Watt per square foot u 4 hours on winter and 2 hours summer

100. High Pressure Sodium u 0.3 Watts per square foot u 1500 square feet per 400 W fixture (theory) u Equals 40 x 40 spacing u … but 45’ high

101. High Pressure Sodium Installation at Bordine’s Better Blooms, Clarkston, MI u 5 lamps in a 30’ x 150’ house (4,500 sq ft) u Lamps 13’ from end walls, spaced 25’ u 0.5 watts per square foot u 15 fc in all corners u 30 to 35 fc under lamps

102. Lighting system over perennials

103. Moving High Pressure Sodium u Attach lamps to a boom u Cycle boom back and forth every 30 minutes or less

104. Moving High Pressure Sodium Installation at Center Greenhouse, Denver, CO u Two 1000-watt lamps on a boom u 35’ x 275’ house (6125 feet) u 0.35 Watts per square foot (equivalent) u 700 fc under lamps, 150 fc on edge u Round trip every 16 to 18 minutes

106. High Pressure Sodium Moving Boom Installation at Mid-American Growers, Granville, IL

107. Lighting Costs Watts per square foot times electrical rate per KWH equals cost per 1000 square feet per hour Watts X $ per KWH = cost per 1000 ft 2 ft 2 Hour

108. Electrical Cost per 1000 ft 2

109. ___________________________________________________ Points to Remember Night interruption or day-extension lighting is more effective than predawn lighting for inducing flowering For rapid and uniform flowering, night interruption should be four hours long with lights on the entire four hours In most perennials, provide at least 10 footcandles to induce flowering

110. ___________________________________________________ Points to Remember Standard mum lighting is adequate to induce flowering in many perennial species Cool white fluorescent, high pressure sodium or metal halide lights are also effective and will result in more compact plants for some plant species

111. QUESTIONS?