Technical Information Bulletin

SUBJECT: CROP SCHEDULING

Use scheduling as a planning tool to produce high quality blooming poinsettias that reach the desired height and flowering dates. Using the forms provided, each product should be ‘scheduled’ as part of the planning process before cuttings arrive at the greenhouse.

Product Specifications: Before developing a production schedule, define the product specifications. How tall do these poinsettias need to be? How many branches and bracts are required at time of sale? What pot size(s) will the crop be grown and sold in? How many plants per container are required? These are all questions that need answering before developing the schedule.

Market Date: Define the date(s) on which poinsettias should be ready for sale. This helps reduce credits or returns on product that are either too mature, or immature at the time of delivery.

Cultivar: Factor in the growth habit and flowering response of each cultivar. These characteristics influence the amount of vegetative growth needed to achieve the desired finished height. The flowering response time also defines how early or late plants will be ready to sell. Manipulation of the day length may be required, or a change in cultivars made to hit the market date. Table 1 identifies these characteristics of poinsettias offered by the Paul Ecke Ranch.

Flower Initiation Date: Determine the flower initiation date by using the market date and count backwards by the flowering response time of each cultivar used. In most regions, poinsettias initiate flower in late September (20th – 30th) when nights become longer than days. The cultivars Autumn Red, Freedom^TM, Pepride^TM, Velveteen Red and Winter Rose Early Red initiate earlier, generally around the 15th – 20th of September. Later initiation may occur in regions where night temperatures are higher than 72°F/22°C. However in these same regions, the warm temperatures and higher light intensities cause a faster rate of flower development, allowing the crop to flower for normal sales.

Photoperiod Manipulation Requirements: If the flower initiation date does not fall within the dates outlined above, use of lighting or blackcloth may be required. If the initiation date is prior to September 20 (September 15 for Freedom or Pepride) blackcloth is required to create 14 hour long night conditions. If the initiation date is after September 30 (September 25 for Freedom or Pepride), lighting is required to interrupt nights between 10:00 PM and 2:00 AM, preventing plants from initiating flower until these lights are discontinued.

Vegetative Growth Requirements: Calculate vegetative growth requirements based on the finished height. This assures plants will have enough time between pinch and flower initiation to form enough leaves to achieve the desired finished height. The time is based on the two key factors; geographic location and vigor of each cultivar. The charts provided (Table 2) suggest the production time for various forms based on location. Next, adjust the vegetative growth time based on height of the cultivar, see Table 3. If a poinsettia listed as “short” in Table 1, additional time will be required to compensate. If a cultivar is listed as “tall”, no additional time is added to the schedule. Once the location and cultivar vigor factors have been calculated, the sum represents the time required from pinch to flower initiation.

Pinch Date: The pinch date is determined by subtracting the vegetative growth requirements from the date of flower initiation. For non-pinched forms, go directly to the transplant date below.

Transplant Date: Before pinching poinsettias, it is advisable to have adequate root systems established. The size of growing container and volume of media influence how long it takes for rooted cuttings to develop adequate roots prior to pinching. Small pots with less soil volume take the least amount of time for root establishment, while large pots with more soil (and greater moisture holding capacity) will take longer. Table 4 suggests the number of days typically needed to develop adequate root systems prior to pinching. As a general guideline, plants are established when they no longer wilt or droop from the shock of transplanting, even during the warmest part of the day. Roots should be visible to the side and bottom of the pot. Using the values in Table 4, subtract the number of days from the pinch date to determine the optimum transplant date. Less time may cause sporadic branching and less uniform development.

Propagation Date: If direct sticking, the amount of time required to have cuttings sufficiently rooted and ready to pinch is usually 5 weeks. If cuttings are rooted in Jiffy® plugs, oasis®, rockwool® cubes or other such media, the propagation period is approximately four weeks. Therefore, using the transplant date identified above, count backward another 4 weeks to determine optimum propagation date for the crop.

                                                                                     TABLE 1

                                                 Click Here For Printable Blooming Poinsettia Production Schedule Form

©1999 Paul Ecke Ranch All Rights Reserved	.
We hope the information provided will be helpful. It is based upon data and knowledge ( including information provided by the recipient) considered to be true and accurate, but without independent investigation and is offered for the recipient's consideration, investigation and verification, but we do not warrant the results to be obtained. Please read all statement, recommendations, or suggestions in conjunction with any conditions of sale or use which apply to any products, or systems recommended by us. No statement, recommendation, or suggestion is intended for any use which would infringe any patent/copyright.