Thoughts on Starting Seeds from a few students

Why transplants and not seedling?
By Brook Jacobson

Over the past few weeks, the Horticulture department’s Student Organic Farming class has been planting thousands of seeds and placing them in the greenhouses to germinate.  Why are we doing this?  Why not sow the seeds directly outside, in the field?  Why take the extra steps and do all the extra work?

There are several reasons to transplant instead of seed directly.  The first is that seeds can be started weeks or months before the outside conditions are appropriate.  For example, in 2011 it snowed through March and April, and many crops could not have been started until the weather was consistent and much warmer.  If the Student Farm had waited to sow until it was warm, they might not have been able to sow anything until nearly June.  On the other hand, the greenhouses are always warm, there is no chance of a late frost, and a heavy rainfall won’t wash away the seeds.  Plus, if we start sowing seeds in February, March, and April, Cornercopia can start harvesting as early as the end of May.

In addition to climate, seeding indoors and then transplanting also allows us to better control growing conditions like light, nutrients, weeds, and pests.  It is not possible for weeds to overwhelm small seedlings when there are no weeds in the growing media.  We don’t have to worry about certain crops dying from lack of nitrogen, or from lack of water.  There aren’t any rabbits or caterpillars in the greenhouse that would consume every green thing in sight.

This is why a class of horticulture students have spent so much time filling containers with growing media, carefully counting out seeds from dozens of colorful packets, and keeping watch over the thousands of little sprouts in the greenhouses.

By Cameron Eccles
Over the past several weeks, HORT 3131 has been starting seeding numerous vegetables and herbs for transplants for the Cornercopia Student Organic Farm.  While some of what we are starting as transplants could be directly seeded outside, the short growing season of our climate necessitates that many herbs and vegetables be started from transplants rather than seed for optimal production.  Transplants are also useful for SOF because they allow for succession planting and harvesting to occur.  Crops that are started as transplants in early spring will mature faster than those that are direct seeded; alternating between planting seeds and transplants throughout the growing season, particularly the beginning of a growing season will allow for a continuous harvest as crops started at different times will be reaching maturity at differing times. 

In planting seeds for transplants for SOF, we have been using soil blocks, which have their advantages and disadvantages.  The main advantages of using soil blocks is that the roots are transplanted entirely with the plant, being confined in their soil block, and because of this there is less shock to the plant during transplanting and the plant is able to adapt to its new environment more quickly.  The disadvantage of using soil blocks is that the blocks dry out very quickly, being surrounded on all sides but the bottom by air.  Because of this, we place our seeded soil blocks in a mist house to ensure that they stay sufficiently moist for successful germination.

By Jenean Lukes
            This season already we have planted seed from over 30 species and several different varieties within those species. All of these species have been planted in about 4 hours a week while the HORT3131 class has their lab session. The process involves making soil blocks that various farm volunteers are nice enough to do before lab, organizing who's planting what, making labels for identifying the varieties and species, planting the seed and transporting to the greenhouse. Sounds like a lot of work, right? With 40+ students to help, we make fairly quick work of this at no cost to the farm. Seeding by hand is a very labor intensive process. This begs the question, “How do large operations start their seeds without breaking the bank in labor costs?” Well I was fortunate enough to be able to tour a large scale organic farm a few weeks ago and I saw exactly how they do it. Mike, the farm's crop and harvest manager, gave me a tour of the farm and showed me some amazing machinery that makes quick work of seeding a flat. The soil blocks we make for the SOF are replaced with plastic trays that come in different sizes. These trays move through a conveyor belt and to a machine with a hopper containing a type of potting mix. The hopper shakes the soil into the tray and smooths it down. The hand seeding is replaced by a suction seeder that picks up a seed and places it at a certain planting depth. This machine was adjustable for different seed types. Although the cost of these machines can be significant, the long term reduction in labor will eventually offset the cost.
By Margaret Sappey
            This week in HORT 5131 lab, we are continuing transplants for CityFresh. The species on the long list include: Arugula, Cabbage, Cauliflower, Chives, Cosmos, Dill, Kohlrabi, Marigolds, Marjoram, Mint, Oregano, Romanesco, Scallions, Thyme. In the past I have worked with Cabbage, Cosmos, Dill, and Kohlrabi. In fact, just today I planted some cabbage seeds for transplants for my own garden this summer. In lab, we are using Purple Cow mix in soil blocks.
            Soil blocks are small cubes of pre-moistened dirt that are fit into a mold and are squeezed into the little blocks with a space on top for one or several seeds. The blocks stay together because of the high peat moss content of Purple Cow. Although labor intensive, soil blocks are a great alternative to the classic plastic trays of plugs because they reduce the amount of plastic used, the transplant roots do not circle and girdle the seedling, and ultimately there is less labor involved because no one needs to sanitize large amounts of plastic, there is no transplanting into slightly larger plugs, and they are pretty easy to handle, no fussing with popping the plugs out of the plastic. In addition, the seedlings have a supply of great compost to give the young plants nutrients even after being transplanted. More information on Purple Cow compost can be found at

1 comment:

  1. Hi there, just became alert to your blog through Google, and found that it’s really informative. I’m gonna watch out
    for brussels. I’ll appreciate if you continue this in future. A lot of people will be benefited from your writing. Cheers!
    Heirloom seeds