Easter Lily Forcing Instructions

Tips for growing easter lilies in the greenhouse

Schedule for commercial case cooled lilies 2008
Easter March 23,2008

Bulbs may be received from November 26 through November 28. Let your supplier give bulbs the proper time for precooling. Pot immediately. Do not unpack bulbs until ready to pot. Do not let bulbs dry before potting. Do not store bulbs warmer than 60 to 65 F prior to potting. Assume potting November 27 for this schedule.

November 27
Pot in standard pot with 1 inch of media below the bulb. Drench with 4 oz. Terraclor
and 1/2 oz. Subdue per 100 gallons of water. Start crop at 63 F night and 70 - 73 F day temperatures if cooling is complete. Soil temperature is very important with an early
Easter, use a soil thermometer to monitor temperature. If questions exist about proper cooling use insurance lighting for two weeks after crop emerges. Prepare for this now. If sprouted, plant deep so that the sprout does not stick out more than 1-2 inches. Continue temperatures until emergence. Negative DIF has no known effect until emergence and 10 degree higher day temperatures (especially if there is no sun) will help emergence.

December 10
White roots should be coming visible in some pots. Keep pots uniformly moist. Start
feeding program - DO NOT WAIT.

December 17
First plants to emerge will be visible.

December 25
Many plants should be emerging. Start lighting if needed. Some growers start sorting with emergence for uniformity of flowering and growth regulator applications. Approximate growth 1-2 inches.

January 1
Crop should be emerged. Buds are probably initiating. Move non-emerged plants to warmer areas. Start graphical tracking and strongly consider negative DIF depending on the graphical information. Supplemental nitrogen fertilizer in dry form (for some slow release characteristics and to supply fertilizer even when irrigation's are not needed) is probably needed. Space plants as soon as possible. Do not try to finish a Valentine's Day crop before spacing lilies. Make the second application of fungicide 4 weeks after the first. If your crop is on schedule lower night temp to 60. Approximate growth 1-2 i

January 7
Stem roots become visible at this time also. . Dissect a few plants for evidence of flower initiation so leaf counting may begin. PGR applications and/or negative DIF must be considered depending on graphical tracking information. Approximate growth 2-3 inches.

January 14

During flower bud initiation try not to stress the plants by drying out the crop, high temperatures or use of chemical drenchs.

January 21
Adjust temperatures in relations to leaf counting and leaf unfolding rates. Watch excessively high day temperatures. Approximate growth 3-4 inches.

January 28
Remember a lily doubles in height from visible bud to flowering. Now is especially the time to control height by acting on information obtained by graphical tracking. Lilies must be spaced. Approximate growth 4-5

February 4
Check height, leaf unfolding rate. Check for insects and consider a final supplemental slow release nitrogen application. Approximate growth 6-7 inches.

February 6 - Ash Wednesday
First buds visible. Watch height - it can get away - but if plants are short or stunted, positive DIF will cause them to increase in height. Watch roots. Perhaps a drench is in order. It's been 4 weeks. Approximate growth 7-8 inches.

February 11
Middle date for buds visible, heat those plants without visible buds. Watch roots. Avoid
bad lower leaves by keeping roots healthy, nitrogen feed high and proper spacing.

February18
Last date for visible bud. 30 days before the Wednesday before Easter

February 25
Buds are 1 ½ inch long. Use a bud stick. Drench if not done in previous 2 weeks. Use Cleary's 3336 and one half ounce of Subdue per 100 gallons of water.

March 3
Buds are 2-3 inches long. Double check for aphids.

March 10
Buds are 3-4 inches long. Watch Botryis. First plants may go to cooler at 40 F
Cool plants as soon as first bud is white-puffy.

March 18
The major ship day for most wholesalers.

March 23
Easter Sunday.

Handling of Easter Lilies

Soil
Maximum root growth requires good soil structure and good drainage. A mixture of
an equal part of soil, peat moss and sand drains well. Use ½ - 3/4 of sterilized broken
crock or clean gravel in the bottom of the pot.

Much root rot in lilies has been traced to unclean benches where poinsettias had been,
or old unclean pots broken up for drainage.

Use a soil of medium nutrient level with pH 6.5 to 7.0. If too low, add ground limestone. Sterilize soil to eliminate weeds and disease and sterilize gravel and/or cinders on which
the pots are to be placed on the bench, or set pots directly on boards that are new or
treated with copper naphthenate.

Treating Bulbs
Results of research with various bulb and soil treatments have varied greatly. Growers wishing to treat lily bulbs should soak the bulbs for 30 minutes in a suspension of 25 ounces of Terraclor and 25 ounces of Fermate in 50 gallons of water.

Control bulb mites by soaking bulbs in a miticide for 10-15 minutes prior to planting.

Potting
Pot the bulbs deep enough that the top of the bulb is 1 1/2 - 2 below soil surface.
This stimulates stem roots which develop larger flowers and also support the plant. Use
5 1/2 standard pots for 7-8 and 8-9 inch bulbs and 6 standard pots for 9-10 and
larger bulbs.

Time of Potting
Pot as soon as the bulbs are properly precooled. Precooling of bulbs, breaks dormancy
and gives quicker and more uniform growth. Plant bulbs immediately upon arrival or store
at approximately 40 degrees.

Sorting Plants

Since lily plants do not all grow at the same rate and temperatures vary from place to place in a greenhouse, sort the plants putting slower ones in a warmer location to speed them up and faster plants in cooler locations. Sort plants in mid December and again in mid January.

Moisture
Keep the soil moist for good root action. Lilies form flower buds when shoots are 2 to 3 inches tall. Later the plants can be run slightly dry to help decrease height but don't overdo it.

Fertilizer
Growers having good results should follow their regular practices.
Start feed program with shoot emergence. Depending on your potting soil a balanced fertizer 20-10-20 should work at the rate of 200-400 ppm. If the pH rises to 7.4 use an application or two of annonium sulphate. Some growers with an initial soil pH of 6.5 - 7.0 use a neutral mixture of 12 ounces of nitrate of soda and 3 ounces of ammonium sulphate per 40 gallons, since this mixture causes very little change in pH.

Continue fertilizer applications until flower buds are 2 inches long to prevent leaf scorch in
late stages of growth. Growers who want to use a complete fertilizer should use the Easter Lily or Nitrogen special.

Temperature
60 degrees at night and 70-75 degrees at daytime are standard. Growth is faster as temperature is raised, but forcing at higher than 60 degrees night temperature tends to
stretch plants and blast buds. Change in night temperature affect rate of growth more than
change in day temperature. Be careful not to have the plants in bloom too early - growth will be fast in the clear warm days. For late Easter, growth can be retarded by using 55 degrees night temperature with 65 degrees in daytime.

Storage of Flowering Plants
Just as the first flower is ready to crack at the tip, plants can be stored in a 38-40 degrees

refrigerated room without light. The first flower will be in full bloom one day after removal from refrigerator. Keep soil moist. Be sure temperature is 38-40 degrees.

Lights
Extra heat to speed up growth is preferred to light which causes excessive stretching.
Leaf Scorch
Tip burn of leaves can be caused by nicotine fumigation or spray, or by nutritional unbalance. The exact nutritional cause is not known; the pH of the soil should be 6.5 to 7.0 and nitrogen fertilizer supplied regularly. Avoid fertilizers with a high phosphorus ratio. Use a high nitrogen fertilizer such as 16-4-12 complete soluble fertilizer.

Fertilizer programs vary with the composition of the potting soil and growers practices. Growers should continue fertilizer practices, which have given good results.

Over watering, poor drainage and poor root growth accentuate leaf scorch.

Bud Count
Handle bulbs carefully; removal of bulb scales reduces bud count. Bud count is seriously affected by light intensity. Space plants so leaves barely touch. Avoid houses with dirty glass or shaded by building. Give full sunlight.

Height
Adequate spacing on the bench in clear houses helps prevent stretching. Running plants on the dry side helps shorten lilies but don't overdo it, especially before the plants are 6 inches tall. This is when flower buds are forming.

Fertilizing does not stretch lilies. Research has shown fertilized lilies to be shorter than unfertilized plants. If lilies are too short in mid February, increase height by given light from 75 watt bulbs four feet apart for 6 or 8 hours per night.

Loss of Flower Foliage

Due to lack of light because of crowding, running the soil too dry, lack of sufficient nitrogen and root injury.

Splitting
An infestation of aphids, especially when buds are very small is sure to cause splitting.
Blasting Buds
Plants held in a cold greenhouse may have blasted buds if the sun hits them in the morning while the soil is cold. Give a light shade or water with warm water during the early morning. General poor growing conditions such as inadequate light, root injury by excess fertilizer, improper watering and disease, or poor root growth may all cause blasting.

Care of Plants
Removal of anthers before pollen is shed gives a clear white lily; check over the plants each day. Wrap carefully for shipping to avoid bruising the large trumpets. If necessary to clean blooms, remove pollen with DRY cotton.