Midwinter Musings

Valentines Day. Half-way through February and about 4 weeks until Spring arrives. Too early to start the tomato, pepper, and cucurbit seedlings, but not too early to dream.

Some follow-up on the lettuce. The AC lettuce (leaf lettuce) was exhibiting some strange growth; the leaf edges and centers were turning black.

Whatever it was did not seem to affect the Buttercrunch or Romaine. A little bit of research turned up the possibility that the nutrient solution was too concentrated - too high a concentration of sodium in the water (we are using salt-softened water) can inhibit calcium uptake in lettuce, and if the leaves are deprived of enough calcium at a critical stage, they become deformed and never recover. I will be reducing the nutrient concentration in future batches, and am giving up on raising the AC lettuce hydroponically since it seems so sensitive.

At any rate, we are now in full production, with a new tank of 9 heads going roughly each week. (That's sweet basil growing in the coffee cans.)

Following the instructions of Mike McGroarty (Mike’s Backyard Nursery on YouTube), I built a propagation chamber out of some of the scrap cedar that came off the roof 23 years ago.

Roughly 2 feet by 4 feet, sand and peat moss in the bottom, and I have several hundred cuttings in there to be rooted. Some apple, grapes, weigela, blueberries, upright yews, and emerald spire arbor vitae.

Then, because I am greedy, I built 2 more, about 3 feet by 4 feet, for starting more cuttings - planning more yews, arbor vitae, azaleas, whatever.

I have to finish the lids for those by stapling on the plastic.

Back in March of 2009 I began building my greenhouse (“Mo' Ham, Maude”, 3-20-09; “It's a CLOUDYhouse, Mr. Dirt”, 4-1-09; & “Clearly an Improvement”, 10-19-09).

Over the years I have learned several important lessons.

1. 8 feet x 8 feet is too small.

2. Ventilation is critical.

I have long dreamed of building a new and improved model, but having been impressed in the wrong direction by the performance of the polyethylene cover and seeing the way the polycarbonate (Sun-Tuf™) has held up, my dreaming always ran into the cost of the glazing. The corrugated polycarbonate runs about $1.25 per square foot, plus there would be the cost of the treated wood framing. A 16 x 25 greenhouse with 8’ walls and a moderately pitched roof would need about $1500 in polycarbonate alone.

However, after seeing what Bobby Smith (mhpgardener on YouTube), SSLFamilyDad (on YouTube), and Grow Appalachia (on YouTube) have done with high tunnel poly houses, I think I’m ready to try that. Having gone through 2 winters with my Harbor Freight woodshed, I’n not quite so fearful regarding polyethylene, especial UV resistant varieties. Also, my Better Half has repeatedly told me that I over-engineer things, and keeping that in mind, the lighter framing used in the high tunnels seems to be adequate.

My thoughts are these: Based on the videos from SSLFamilyDad, I think I can cobble together a frame made from 3/4” EMT. Utilizing the support and ventilation ideas shown by Bobby Smith and the Grow Appalachia folks at Berea College in Berea KY, and scouring the net for material prices, I think I can put together a 16 x 24 high tunnel for right around $800 plus some of my other odds and ends on hand (like the vinyl triple-track windows we tore out of Mike’s house on Tampa when he replaced all his windows 15 years ago). Maybe I will finally even get my shed cleaned out!

Here is what I envision. Each hoop will be a 25’ arc (2 - 10’ and 1 - 5’ length of EMT, the sections joined with 6” lengths of 1” EMT as sleeves) which should provide 15.92’ of width and 7.96’ of height. The hoops will be mounted in 1” EMT driven into the ground along the sides at 4’ intervals with about 2’ exposed, to give a total interior height of just under 10’. The 2’ high side sections will be closed with 2x8 treated center-match lumber (which is needed because of the slope of the site). The plastic and wiggle-wire channels for mounting it will run about $350.

The biggest challenge will be forming the arcs. A tubing roller from Harbor freight runs about $180, but looking at the tool reviews and considering the lengths and multiple passes involved to provide an 18” deep arc in a 10' tube, there would be a great risk of twisting the arc out of the plane. I will need to build a bending form, using 3 - 10’ 2x8s, some additional scrap lumber to hold everything together, and a bottle jack. Once the bending form is made, it can be used to duplicate the 16’ wide tunnel numerous times (hint, hint, chilluns). If I can build that bending form, then the only other obstacle is money. Stay tuned for more adventures of Grandpa Jim.