Saturday, March 7, 2009

Natural light

The temperature finally got to fifty degrees today, and that is a virtual heatwave in upstate New York in early March. It has been a long brutal winter, and I just itched to get into the greenhouse to do some preventive maintenance, and generally get it ready for use.

Although the sun was not shining brightly, it was what I might describe as a bright overcast. The temperature in the greenhouse was a comfy 64 degrees, but it felt like summer after enduring the cold of December, January and February.

I wondered if it might be worth turning off the compact fluorescent light I have been using for propagation, and let my seedlings enjoy some natural light for the afternoon. After I decided to bring a few trays into the greenhouse, I also decided to take a light level reading just to satisfy my curiosity.

When looking at the seedlings indoors under the compact fluorescent light they appear to be well lit. And, for all practical purposes, they are, with a level of about 2,000 foot candles. However, even though it was just what I would call cloudy bright, the reading at plant level in the greenhouse was over 4,000 foot candles. Old Sol is still the best source of light when he is available.

The plants in the photo are Bush Beefsteak and Best Boy tomatoes started on 2/14/09. They are not doing as well as I hoped, but they will most likely improve now that they have been planted in pots, and are not just languishing in rockwool cubes. I intend to grow them in the greenhouse in AutoPots, so I placed them in 3" pots to grow until transplanting.

The media is recycled coco coir and perlite. Recycled that is to the extent that I used it last season in the AutoPots. When the plants are removed, there is a lot of media remaining on the bottom of the pots. The media is not rotted, or degraded in any way. Rather than discard that material, I place it in a large tote to dry and reuse it. I purchased a number of the small 3" pots and I intend to grow pots of annual flowers in the greenhouse using this recycled media, and also used nutrients from the ebb and flow systems. I have been changing the nutrients every two weeks, so the used nutrients, along with any residual nutrients remaining in the recycled media, should work just fine to add some color to the greenhouse.

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