Setting The Stage For Spring Production and A Successful Spring Fundraiser by Mike H.

SETTING THE STAGE FOR SPRING PRODUCTION AND A SUCCESSFUL SPRING FUNDRAISER

• Your shade should be off the greenhouse. You’ll need as much  light as possible reaching your plants well into the month of March.  Snow can accumulate on the shade-cloth as well, putting extra weight on  your greenhouse structure. Plants usually fare better without shade till  sometime in the month of April. This can vary by the type of  greenhouse, crops grown, region, etc.
• Check your irrigation  system and controls if you have them. Clean filter, check all emitters.  It’s a good idea to have an extra solenoid on hand if your system uses  them.
• Check your environmental control system to make sure all  louvers, heaters, fans and equipment work as they’re supposed to. Make  sure you know what your day and night-time temperatures should be as  these are key to growing a good spring crop.
• Make sure you have  HAF fans to circulate greenhouse air. Also make sure they’re operational  and are oriented correctly. They should push air throughout the  greenhouse in a rotating pattern. The importance of these fans is often  overlooked. They destratify air layers, help prevent foliar diseases  and, during daylight hours, will help your plants grow by moving air  away from the leaves that has been depleted of carbon dioxide during  photosynthesis. This air will then be replaced with fresh air that has a  higher carbon dioxide content. Thus running these fans both day and  night is a good practice unless your ventilation fans are on. It’s hard  to have too much air movement.

• For hanging baskets bring in plants from the middle to end of  February and use four plants per 10” basket for the best quality. Five  to 6 plants do well in a 12” basket. • For 4” and 4.5” pots, schedule  for the first week in March and use one rooted liner per pot.
• For bedding flats, schedule plugs for the 3rd week in March
• Many  variables may affect this schedule such as your region, date of sale,  market, and growing conditions. The above schedule works best for the  Mid-west including the states of Missouri, Kansas, Indiana, Nebraska,  etc.
• The ultimate goal is to avoid too small or overgrown plants at the time of your sale.

• Bugs are not here because they’re easy to kill. They’re  resilient, adaptive, often bullet-proof creatures that will be with us  forever.
• Prevention and early detection are best in preventing  problems. Yellow Sticky cards and routine monitoring go far in detecting  these pests before they become an issue.
• Check under leaves and  on new plant material especially on the newest growth. Most growers  ship clean plant material but some harvest off of their own stock plants  which can harbor such pests.
• Avoid overwintering pet plants  such as outdoor tropical hibiscus, palms and other ornamentals. If your  principal wants a winter home for his/her hibiscus, please make the  argument against it. These plants harbor just about any kind of  insect/mite/pest you can imagine. Outdoors they are not really visible  but once brought into the utopian greenhouse environment they’ll  manifest themselves and spread, potentially to everything in your  greenhouse.
• If you have stock plants that you use for class projects, propagation, etc., please monitor carefully and routinely.
• No weeds should be in the greenhouse. These are also sources of all kinds of insect pests.
• Remove  any algae or peat moss on walkways, along the edges of the greenhouse  or in the gravel. This is very attractive to fungus gnats that will lay  eggs in this media causing flying gnats in short order. Top-dress with  fresh gravel to avoid this. If you have concrete floors this shouldn’t  be a concern.
• Consider beneficial insects. They are available  now in smaller quantities and would make for a great class project.  While conventional chemical controls do have their place, this would be a  much easier/safer option in the school setting, especially with food  crops and students in the greenhouse.

• Spring crops are short term so it is best to keep your fertilizer regimen simple.
• In  most cases, the general purpose 20-10-20 is best with all peat based  soil mixes. It is a formation made for growing where the often used  20-20-20 is useful primarily for maintenance. I know some still use this  but better results should be seen with the 20-10-20.
• When  fertilizing it is best to apply with each irrigation at about 200 PPM if  possible. Of course I know this may not be possible for all but it is  much better to fertilize often as these plants are hungry and will  develop much better with frequent/adequate nutrition.
• Do not fertilize if dry. The salts in the fertilizer can injure dehydrated roots, causing leaf edge burn….or worse.

• If using a good fertilizer there are typically few pH issues  with spring annuals since their crop time is relatively short. Most  fertilizers acidify the irrigation water, which along with the soil pH  of about 5.9, will keep the soil pH in the normal range for most plants.  This reinforces the argument for fertilizing with each irrigation. Soil  pH tends to drift up with most municipal waters that are typically very  alkaline. Once that pH gets near 6.8, problems may develop.
• Calibrachoas  and petunias the first to show symptoms of this pH drift. They’re very  sensitive to the diminished uptake of iron caused by high pH. They serve  as that “canary in the goldmine” indicating a looming problem for other  plants if not soon corrected.
• This pH topic can be quite  complicated but fortunately proper greenhouse practices can avoid most  problems that may develop before becoming a real issue.
• If you  don’t already have one, please invest in a pH meter to keep an eye on  your soil as well as an EC meter which will help you with your  fertilizer rates. This routine testing would be a great project also for  the students to take part in.

Happy Growing!