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Scheduling Greenhouse Crops


Scheduling is an important part of greenhouse crop production. Accurate schedules are required to grow plants to marketable size at the right time of year.  Poor scheduling may cause growers to experience having small or non-flowering plants, having overgrown plants at the height of the season or empty benches with several weeks of selling season still ahead. There are many factors that can influence finish timing of bedding plants including the maturity of plugs and liners, growing conditions for the plugs and liners, average day-time temperature, photoperiod, use of plant growth regulators and finish container sizes. Chronological age (calendar age) vs. physiological age of the plant is always a challenge and production decision affect crop timing.

To successfully schedule a crop, a grower has to decide the week of the year that a crop will be marketed, and then work backwards to determine the date of seed sowing or planting (depending on the crop). If seedlings, plugs or liners are purchased, then the dates of delivery and transplanting will need to be determined.

For spring crops, if a grower knows how many packs of each plant species will be grown, the amount of seed or number of plugs that will be needed can be calculated and a seed (plug) order can be compiled.

Many growers schedule their spring crop plant and seed shipments during October to be able to compensate for inevitable backorders and potential crop failure announcements. A spreadsheet will help to maintain records and keep things organized from year to year. In the spread sheet record the following information for each cultivar:

  • Seed source
  • Amount of seed
  • Number of plug trays to sow at each sowing
  • Number of packs to transplant from each sowing
  • Plug trays left over after transplanting
  • Various size containers (4-inch, 6-inch, baskets, etc.)

Some growers also prepare a master sowing schedule for each week that lists the crops alphabetically which are scheduled to be sown. Each crop can be checked in the spreadsheet to see what cultivars are to be sown and how many plug trays of each. Sowing instructions are also recorded, such as whether seed should be covered etc. Any changes from this list should be recorded.

A file should also be maintained for vegetatively propagated plant material. A spreadsheet could be developed that includes:

  • Number of cuttings to stick on various stick dates
  • Number of pots or baskets to plant
  • Cultural information for each

From these individual schedules, a master propagation schedule can be put together.

Interactive Decision-Support Tools for Scheduling

There are on-line, interactive tools available to provide guidance in scheduling bedding plant crops.

FlowersOnTime  by Paul Fisher (University of Florida), Erik Runkle (Michigan State University), Matthew Blanchard (Michigan State University), and John Erwin (University of Minnesota) Once on this website, you will be asked to provide your email address and the link to download the program will be sent to your email address.

FlowersOnTime is a computer decision-support tool in Microsoft Excel that quantifies how a change in greenhouse air temperature would affect flower timing for a range of floriculture species. This information is helpful when growers are considering reducing greenhouse air temperature in order to save on heating fuel cost, or because they want to achieve a target flowering date by manipulating temperature. There are 60 plus floriculture crops in the drop-down list with finish times based on temperature.

Virtual Grower 3.0 Users of the software can build a virtual greenhouse with a variety of materials for roofs and sidewalls, design the greenhouse style, schedule temperature set points throughout the year, and predict heating costs. Different heating and scheduling scenarios can be predicted with the input of a few variables, with accurate data based upon historical records collected by USDA monitoring stations across the country. The software also includes a crop timing tool for 35 floriculture crops.
The article Scheduling Bedding Plants describes how this software is used for scheduling.

Guidelines and Charts

In addition to interactive software, commercial seed and plant supply companies supply guidelines and charts available on-line and some are listed below.

Greenhouse Grown Annuals, Perennials, Vegetable and Herb Bedding Plants

Ball Seed: Production Guides
Ornamental Bedding Plants (Chart-Ball Seed)
Ornamental Plant Plugs (Chart- Ball Seed)
Vegetable and Herb Plugs (Chart-Ball Seed)
Growing Vegetable Transplants and Bedding Plants : Cultural and scheduling information (UMass Extension)
Grower Success Guide (Syngenta) Cultural information and scheduling charts

Vegetatively Propagated Spring Annuals

Ball Publishing webinars: See "Growing a Better Liner" parts 1&2 for information on rooting cuttings.
Proven Winners: Cultural information in data base format. Use the drop down menus to see list of plants.

Cut Flowers - Greenhouse, High Tunnels

Cornell University: Cool season crops for spring, Main season crops for summer, Cool season crops for fall
Book - Specialty Cut Flowers: 2nd Edition. Timber Press, Portland, OR. 636 p.Armitage, Allan, and Judy Laushman. 2003.
Provides extensive coverage of annual, perennial, bulbous, and woody species for commercial cut flower production, including propagation and growing-on methods, environmental factors, yield in the field, greenhouse forcing, stage of harvest, postharvest handling, and pests and diseases. Available for $40 ($35 for members) plus s/h from Association of Specialty Cut Flower Growers (ASCFG),

Greenhouse Tomatoes

Scheduling Greenhouse Tomatoes  Rich McAvoy, University of Connecticut