Greenhouse Report: The Upcoming Growing Season

Mar 19 by in General, Greenhouse tagged with 2 comments


Tomorrow marks the official first day of spring, and the greenhouse staff at Arbor Day Farm is busy getting ready for another production season. It’s true that we grow year round, but during the spring and summer we take advantage of nature’s kind gifts – sunlight and longer days – and grow an outdoor crop as well.

All plants grown at Arbor Day Farm’s greenhouses are propagated from seed. During the month of May, we will sow over 250,000 seeds – Colorado Blue Spruce, White Pine, Norway Spruce, and Bald Cypress. As you might imagine, sowing a quarter of a million seeds by hand would take an enormous amount of time. So we embrace another gift – the gift of mechanization and technology – to help us keep up with the demand.

Here’s how we get growing at Arbor Day Farm…

Step 1: Preparing the Growing Trays. At Arbor Day Farm’s tree growing facilities, healthy, thriving trees start with well-prepared growing trays. Each tray is approximately 23″ x 14″ and has 160 cavities, and sterilizing them greatly reduces the bacteria and fungus that can hinder growth.

Step 2: The Importance of Peat. Each sterilized cavity in the tray is filled with peat moss, a soil-less media, that allows the perfect mix of water-holding capabilities for the seed as well as proper drainage.  Peat brings a delicate balance to the growing process, ensuring that the seed isn’t too wet or too dry. This perfect blend allows just enough air in the cavity to establish the roots to develop and breathe.

Step 3: Precision Planting. I’ve been in the tree business for 11 years, and I still find it fascinating to watch this planter in action. The planter features a set of small nozzles that are pre-set to the exact width of our growing trays. Using suction much like that of your home vacuum cleaner, each nozzle picks up a single seed and then uses a fast puff of air to place the seed in each growing cavity. Shown in this photo: the planter’s tiny nozzles grab a white pine seed, dyed red to make them easier to see. Image below: white pine seed at one month after germination.

Step 4: Just Add Water. Bring on the moisture and nutrients! Unlike natural earthen soil, the peat (see Step 2) has no nutritional value for the seed. So we compensate for that by injecting just the right amount of a feed blend through the greenhouse water lines. The seedlings take in the nutrients they need, compartmentalize and use each element as necessary, and they release or leach the built up salts and underutilized nutrients with the next watering.

By early fall, these germinated seeds will produce over 200,000 tree seedlings – seedlings that are used in the Arbor Day Foundation’s Gift Tree program, as well as the seedling you’ll receive on your next visit to Arbor Day Farm.

I invite you to stop in and get a first-hand look at the tree growing operations at Arbor Day Farm during this special time of year, and watch our mission literally come to life.

Adam Howard is the Manager of Nursery Operations at Arbor Day Farm and a Certified Forester with the Society of American Foresters. He has been in the forest industry for 11 years and contributes regularly to this blog. Contact Adam with your greenhouse questions.

« Back to Home


  • Joe Battersby says:

    Adam, just curious; is the precision planter homemade or store bought? Very ingenious!

  • Robert says:

    Wow what an inspiration to see. I live in Brisbane, Queensland, in Aus. Have just started my first sproutings. I have 10 now just starting to germinate they are fascinating to watch. This tree has amazing processes. Thanks for the page :)


Trackbacks and Pingbacks

Leave a Comment