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: 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

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 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

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) 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 63-65 F night and 73-77 day temps and a medium to high (greater than 2500 Foot Candles) light intensity greenhouse

Checklist cont… When required for height control, apply A-Rest 10-14 days after planting Pinch single and strong double/weak-shooted plants at third or fourth node 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 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

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: Single Flowered Anemone Collerette Peony-flowered Decorative Ball Pompon Cactus Semi-cactus Misc. Types

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

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