Non-Rooting Room Bulbs

March 28, 2004

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

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

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

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 35-48 F depending on variety)

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

Nonrooting Room Bulbs(to know)

• Amaryllis (Hippeastrum)

• Canna

• Calla (Zantedeschia)

• Crocrosmia

• Dahlia

• Incarvillea

• Lilium

Nonrooting Room Bulbs(Other)

• Begonia

• Calochortus

• Eucomis

• Gladiolus

• Leucocoryne

Amaryllis (Hippeastrum)

• Plant from winter to spring

• Plant one bulb per standard 6” pot– Nose should be above media

• Grow at 70-85 F for at least 2 weeks to root

• Flowers last for about one month

• Use for large containers or interiorscapes

Canna

• Subclass: Monocotyledon

• Family: Cannacea

• Primary Use: Containers

• Flowering Season: Summer

• Hardiness: Tender III

Planting, Watering, and Fert.

• Plant in Spring• Well drained soil• Some organic matter• Fertilize 1-3 times during the growing season

– Applications of 12-10-8

• Tolerate some drought but do best if kept moist• For containers use dwarf type cultivars

– ‘Chinese Coral’ and ‘Lucifer’

Growth and Flowering

• Cultural Requirements:– 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

Flowers

• Petaploid stamens

• Colors include coral, cream, orange, pink, red, or yellow

• 3 sepals, 3 petals, and up to 5 stamens formed

Foliage

• Long wide leaves

• Color is green to bronze while some are variegated

Major Diseases and Pests

• Bud Rot (Xanthomonas cannae)

• Canna Mosaic Virus

• Botrytis cinerea

• PESTS: Japanese Beetles and Slug and Nails

Calla (Zantedeschia)

• Two types– 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

Crocosmia

• Common name is Crocosmia:– Crocosmia sp.– Montbretia hybrids

• Dried flowers smell of saffron; Greek:– Krokos (saffron)– Osme (smell)

Crocosmia Bulb Structure

• Corm– Probably has contractile roots (DeHertogh and Le

Nard, 1993)

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

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 50-64.3 cm

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

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

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

Dahlia x

• Subclass: Asteridae• Family: Compositae

• Primary Use: Containers• Flowering Season: Summer• Hardiness: Tender III (injured at temps

below 35 F)

13 Step Checklist(From the Holland Bulb Forcer’s Guide)

1. Purchase only specially-grown cultivars2. On arrival, inspect for freezing injury, physical

damage, and diseases3. Store tuberous roots at 45 to 50 F4. Use a well drained, pH 7, sterilized planting

medium5. Plant tuberous roots with crown above medium6. Keep planting medium moist, BUT NOT WET7. Use 63-65 F night and 73-77 day temps and a

medium to high (greater than 2500 Foot Candles) light intensity greenhouse

Checklist cont…

8. When required for height control, apply A-Rest 10-14 days after planting

9. Pinch single and strong double/weak-shooted plants at third or fourth node

10. After plants begin to grow, use either 14-14-14 osmocote or a liquid fertilizer program of 200ppm N of 20-20-20 2-3 times per week

11. When desired, spray dwarf cultivars with 66 PPM of A-Rest

12. Do not place marketable plants in cold storage13. Ship marketable plants at 55 to 60 F

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

Planting• Plant in late winter to Spring• Use one tuberous root per 6” diameter pot

– Use 3 or more in large containers

Fertilization

• Requires continuous fertilization after visible shoot growth

• Complete NPK required• Top dressed slow release fertilizer (14-14-

14)• Apps. of 200ppm N of a 20-20-20 soluble

fert. can be used 2-3 times a week– Use this liquid feed to supplement the slow

release

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

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--- 7 days

1” Flower bud--- 4 days

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

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

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

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

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

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:

1. Single Flowered2. Anemone3. Collerette4. Peony-flowered5. Decorative6. Ball7. Pompon8. Cactus9. Semi-cactus10. Misc. Types

Pests

• Aphids

• Beet Army Worm

• Red Spider

• Thrips

• White Fly

Physiological Disorders

• On occasion, tuberous roots will fail to develop shoots– Caused by sterile roots or crown gall.

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

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

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

Calochortus

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

Leucocoryne

• Plant in mass for best results

• Off white to faded purple type color

• Grass like foliage