1. Non-Rooting Room Bulbs
March 28, 2004

2. Concepts of Forcing “Rooting Room Forcing”
Technique of “standard forcing” is used
Immediate post harvest temps control rate of flower initiation and formation
Rooting takes place during cold treatment
“Greenhouse Phase” only used to elongate flower stalks and expand the leaves

3. Concepts of Forcing Cont…
“Non-Rooting Room” forcing
Primary difference to “standard forcing” is that rooting takes place in the greenhouse
For some, flower initiation and development also take place in the greenhouse phase (Easter Lilies and Dutch Iris)
“Non-Rooting” does not mean no cold treatment
There are two types of “Non-Rooting Room” bulbs

4. Special Precooled Developed for specific markets
Bulbs undergo certain cold treatments in order to bloom at certain times
An example is tulips grown as cut flowers for valentines day

5. Standard “Non-Rooting Room” Bulbs
Exemplified by the Calla Lily
Perennial bulbs that is cycled in and out of the greenhouse
Generally have some type of short storage requirement (i.e. Calla Lilies require a minimum of 6 week postharvest storage at F depending on variety)

6. Programming Phase
Many “Non-Rooting Room” bulbs still have programming phases. This involves:
harvesting the bulbs at the correct stage
Proper handling and storage
Sufficient cold treatment

7. Nonrooting Room Bulbs (to know)
Amaryllis (Hippeastrum)
Canna
Calla (Zantedeschia)
Crocrosmia
Dahlia
Incarvillea
Lilium

8. Nonrooting Room Bulbs (Other)
Begonia
Calochortus
Eucomis
Gladiolus
Leucocoryne

9. Amaryllis (Hippeastrum)
Plant from winter to spring
Plant one bulb per standard 6” pot
Nose should be above media
Grow at F for at least 2 weeks to root
Flowers last for about one month
Use for large containers or interiorscapes

10. Canna Subclass: Monocotyledon Family: Cannacea Primary Use: Containers
Flowering Season: Summer
Hardiness: Tender III

11. Planting, Watering, and Fert.
Plant in Spring
Well drained soil
Some organic matter
Fertilize 1-3 times during the growing season
Applications of
Tolerate some drought but do best if kept moist
For containers use dwarf type cultivars
‘Chinese Coral’ and ‘Lucifer’

12. Growth and Flowering Cultural Requirements: Can grow up to 9 ft tall
70-85˚ F Summer
41-50˚ F Winter
Can grow up to 9 ft tall
Flower for 2-3 months in summer
May be affected by Jap. Beetles in mid-summer

13. Flowers Petaploid stamens
Colors include coral, cream, orange, pink, red, or yellow
3 sepals, 3 petals, and up to 5 stamens formed

14. Foliage Long wide leaves
Color is green to bronze while some are variegated

15. Major Diseases and Pests
Bud Rot (Xanthomonas cannae)
Canna Mosaic Virus
Botrytis cinerea
PESTS: Japanese Beetles and Slug and Nails

16. Calla (Zantedeschia) Two types Primarily used in containers
Z. aethiopica planted in fall and grown cool
Colored cultivars planted in spring and grown warm
Primarily used in containers
Tender II: Injured at temps below 50 F

17. Crocosmia Common name is Crocosmia:
Crocosmia sp.
Montbretia hybrids
Dried flowers smell of saffron; Greek:
Krokos (saffron)
Osme (smell)

18. Crocosmia Bulb Structure
Corm
Probably has contractile roots (DeHertogh and Le Nard, 1993)

19. Growth, Development, and Flowering
Summer Growing
Corms dormant in winter
Flowers in summer
*Currently there are no reports available for effects of temperature and photoperiod on the growth and development of crocosmia

20. Recent Study Study by Armitage and Caushman (1990)
Planted cv. ‘James Coey’ in January, February, and March
All started flowering in July
Total Plant Height was cm

21. Planting, Watering, and Fert.
Generally 2-3 cm deep
Well drained soil
Well composted soil
Fertilized once at planting
Fertilized again 4 weeks later
Keep well watered in summer
*All according to normal field growing practices of Dutch growers

22. Major Diseases and Pests
Fire (Botrytis gladiolarum)
Can affect the leaves, flowers, and corms
Dry-Rot (Stromattinia gladioli)
Can affect roots and corm
Corm Rot (Fusarium oxysporum f. sp. gladioli)
Primarily affects the corm
PESTS: Red spider mites

23. Brent and Becky’s Description
Up to 50 tubular, starry, warm, colorful blooms
Blooms on 24”-36” gracefully arching stems
Pest Resistant
Sword like foliage similar to glads
Blends in nicely adding linear accents
Best in full sun

24. Dahlia x Subclass: Asteridae Family: Compositae
Primary Use: Containers
Flowering Season: Summer
Hardiness: Tender III (injured at temps below 35 F)

25. 13 Step Checklist (From the Holland Bulb Forcer’s Guide)
Purchase only specially-grown cultivars
On arrival, inspect for freezing injury, physical damage, and diseases
Store tuberous roots at 45 to 50 F
Use a well drained, pH 7, sterilized planting medium
Plant tuberous roots with crown above medium
Keep planting medium moist, BUT NOT WET
Use F night and day temps and a medium to high (greater than 2500 Foot Candles) light intensity greenhouse

26. Checklist cont…
When required for height control, apply A-Rest days after planting
Pinch single and strong double/weak-shooted plants at third or fourth node
After plants begin to grow, use either osmocote or a liquid fertilizer program of 200ppm N of times per week
When desired, spray dwarf cultivars with 66 PPM of A-Rest
Do not place marketable plants in cold storage
Ship marketable plants at 55 to 60 F

27. Bulb Type Tuberous Root System Primarily enlarged root tissue
Crown containing one or more apical shoot meristems
Root primordia develop from distal end of enlarged roots

28. Planting Plant in late winter to Spring
Use one tuberous root per 6” diameter pot
Use 3 or more in large containers

29. Fertilization
Requires continuous fertilization after visible shoot growth
Complete NPK required
Top dressed slow release fertilizer ( )
Apps. of 200ppm N of a soluble fert. can be used 2-3 times a week
Use this liquid feed to supplement the slow release

30. Temperatures Force at a min. night temp. of 63-65˚ F
Lower temps will delay flowering
Day temps should be 73-77˚ F
Higher day or night temps will accelerate flowering
AVOID TEMPS ABOVE 80˚ F
To delay flowering, lower the night temps to 55˚ F

31. Forcing Times from Various Bud Stages to Opening of Flower (Depending on the cultivar)
½” Flower bud---14 days
5/8” Flower bud---10 days
¾” Flower bud days
1” Flower bud days

32. Growth and Flowering Cultural Requirements:
Grow at 60-65˚ F for 5-8 weeks
Market in USDA Zones 4 to 7 after the danger of the last frost has passed
Grow in full sun

33. Pinching
Tuberous roots produce range of single, or multiple stemmed plants
Single strong shoot must be pinched
High quality plants
Maximum number of flowers
Optimal stage to pinch terminal shoot: after the third or fourth pair of leaves has unfolded

35. Where to Pinch Dahlias normally form 2-4 pairs of simple leaves
1st Pair: Small, about 0.5” in length
2nd Pair: 1-2”
3rd Pair: 3-4” sometimes trifoliate
4th Pair: 3-4” either simple, trifoliate, or pinnate
Pinch removes all terminal growth above the 3rd or 4th pair of leaves
give 2-4 lateral shoots

37. Pinching cont… Also some double stemmed plants that need to be pinched
If one shoot grows stronger than the other, pinch the strong shoot
Do not pinch shoots growing equally
Do not pinch if 3 shoots are growing
Do not allow more than 3 shoots to grow

39. Pinching cont…. Pinching will delay flowering 5 to 10 days
Pinched plants are slightly taller
If pinching is not done at optimal stages, flowering can be delayed
Low vigor plants are not pinched with the rest of the rest of the crop

40. Flowers Flowers form after 5-7 pairs of leaves
Colors: Solid, Bi-color, or multicolored
Royal Horticultural Society in Great Brittain divided flowers into 10 basic groups:
Single Flowered
Anemone
Collerette
Peony-flowered
Decorative
Ball
Pompon
Cactus
Semi-cactus
Misc. Types

41. Diseases
Viruses: Main disease: Infestations should be reported to bulb supplier
Apply a soil drench of a fungicide shortly after planting to give protection against root rot organisms

42. Pests
Aphids
Beet Army Worm
Red Spider
Thrips
White Fly

43. Physiological Disorders
On occasion, tuberous roots will fail to develop shoots
Caused by sterile roots or crown gall.

44. Incarvillea sp. Plant in spring Expect a 14” leaf spread
Use one tuberous root per 6” standard pot
Cover crown of root with about 3” of medium

45. Lilium Can plant in fall, winter, or spring
Can go in variety of pot sizes and containers
Root for only 2-3 weeks in greenhouse and then market
Asiatic and Oriental types
Hardy I: injured at temps below 23F

46. Begonia Plant in spring Grow at 60-65F
Long days will promote earlier flowering
Will flower for entire summer
Use for hanging baskets or containers
Tender III: injured at temps below 35F

47. Calochortus

48. Eucomis Plant in Spring Use at least 3 bulbs in large containers
Fertilize 2-3 times during the growing season
Tender II: Injured at temperatures below 50 F

49. Leucocoryne Plant in mass for best results
Off white to faded purple type color
Grass like foliage