Homegrown, organic salads in a Midwest winter

Portable greenhouse with Earthboxes filled with greens inside

Saturday, December 31, 2011

With some protection, you can enjoy fresh, organic salads through the winter.  Last year, my greens (lettuce, chard, mustard, dill, and parsley) made it all the way through our cold, snowy Ohio winter with my little pop up greenhouse.

This year, I am using the pop up greenhouse over 2 Earthboxes and a potted celery plant.    Pictures above show the greenhouse zipped up on left and opened on right.  I have it set up on the patio next to our outdoor kitchen.  Our patio is on the south side of the house so they will get the maximum sun and warmth exposure.  I will also add 3 black painted gallon milk jugs filled with water today as the forecast is for teens tomorrow.

The concrete does a great job of absorbing heat from the sun that should radiate back to the plants at night.  The downside of using pots is that pots cause the effective zone to drop by 1 or 2 since they are exposed on all sides.  So, it is an experiment to see if the upside of the concrete overcomes the downside of the pots.

Last year, I used the greenhouse over salad greens planted in the ground.  I read about this trick of taking water jugs, painting them black and putting them inside the greenhouse, which I did.  Success!  My plants made it all the way through the winter whereas the previous year they only made it into January.

Another trick to winter gardening is you have to have your plants at mature height by the time you are down to 10 hours of sunlight where you live.  There is not enough daylight (less than 10 hours) between November 9 and January 26 to support significant plant growth here in Cincinnati, Ohio.  What you have on November 9 is what you will harvest from until January 26 in this area.  

This means sowing seeds in August/early September.  It is painful to me to pull up all the tomatoes, cucumbers, eggplants, peppers that are still going strong at this time of year to plant cold hardy greens.  That is why I am trying the Earthbox approach this year.  You have to resow lettuce and other heat sensitive greens in August since they have bolted in the heat.  

I have found that growing salad greens in the Earthbox works great spring through fall.  You can keep them in sun when it is cool in the spring and fall and be able to move them to the cooler, shadier side of the house when it is hot.  You maximize your harvest through all the seasons.

With my salad greens already going strong in the fall in the Earthbox, I can just cover the salad greens when it starts dropping in the 20’s in their existing pot and not have to pull the heat lovers until the frost gets them.  I get to maximize my harvests of both!  Gotta love that.

It is important that you fertilize the pots well through all the seasons.   Lettuce sucks nutrients, what they call a heavy feeder.  I add compost every month and use a liquid fertilizer once a week, alternating between bat guano, seaweed, and fish emulsion.  

I don’t use any insecticides on my salad greens.  

When we first moved here, we were having our lawn treated with herbicides and insecticides.  There were hardly any insects around.  We went to all organic for the lawn 4 years ago and discontinued our lawn treatments.  Two years ago, I saw praying mantis for the first time.  They were back this summer.  We are finally getting beneficial insects as permanent residents.  When you have a good population of beneficial insects, they can keep the others under control.