Tuesday, April 12, 2011

Greenhouse seed starting; nitrogen pollution

Today I finally started using my greenhouse for what it was intended (other than as a writing studio): I started some seeds in flats and them left them in my greenhouse to see how they do. I'll have to make sure I ventilate it each morning, and close it at night, because unventilated it gets up to 100 degrees in there on warm sunny days, but still goes down to frost temps at night. I've started my warm-weather crops to take advantage of the heat in there: cantaloupe, zucchini, cukes (a variety called Poona Kheera, which is new to me), basil (regular and Thai), and parsley.

I still have to put my peas in the ground! I'm almost too late, but it's time to start sowing my raised bed, now that I can fully work the soil. (I tried early last week, but it was still frozen a few inches down.)

Why I only use organic fertilizers (like compost, or seaweed extract): I heard today on the BBC's Farming Today that nitrogen pollution is costing every person in Europe up to 650 pounds a year to clean up -- due to over-use of chemical nitrogen by farmers and gardeners. That doesn't count the cost of nitrous oxide in the atmosphere, which is a leading cause of global warming. (Yes, I listen to Farming Today! It's a good show.) Organic fertilizers break down more slowly, meaning less is unused by the plants and subsequently released into the groundwater or atmosphere.


  1. I'm actually working on a blog post on this topic. Two big aspects of gardening and pollution:

    1. Nutrients - this normally isn't a huge issue because in many cases, gardens (even overfertilized) take the place of what were heavily fertilized lawns.

    2. Toxins - this may be a big issue because conventional gardeners SIGNIFICANTLY overuse pesticides (and all chemicals).

    I'm like you - my garden is 400sf of raised beds (and I'm trying no-till) in a community garden full of old, conventional gardens throwing around lots of chemicals. Somehow, my production is better than 75% of them ;)

  2. Probably if you're using traditional fertilizers like compost, you're slow-releasing nutrients to your plants, which means they take up more of the nutrient. As you note, people often overuse fertilizers on their plants, but do so at odd intervals, so that most of the fertilizer leaches out through the soil and isn't taken up by the plants. Then they blame the plant.

    Good to have you reading the blog. I look forward to doing the same.

  3. (Follow-up.) I see you're based in the Chesapeake: yes, run-off into the Bay is a serious problem!