Thermal Mass

The first year of the greenhouse's life I was dying to get started.  It was March, and there was snow on the ground and freezing temperatures at night.  I didn't want to use fossil fuel to heat the greenhouse, so I embarked on a solar exploration.

Let me introduce the concept of thermal mass: this is the storage of heat energy (thermal) in some object (mass).  Typically, stone and water make great objects for thermal mass storage.  The general idea is that the thermal mass gains energy (heat) during the day when the sun is shining and gives it up at night when the temperature falls.  The point of equilibration (ie, the steady-state temperature) is dependent upon the high-low temperature range, the strength of the sunlight, and the amount of thermal mass available.  Very complicated stuff!  Let me say that I did not take AP physics in high school.  In fact, I took only a rudimentary physics course in college.  Fortunately, in addition to being the best husband in the world, my husband is also a genius mad scientist. We spent weekend after weekend covering every available piece of paper with calculations, read every available book in print on solar heat for greenhouses, talked to solar contractors about battery and complicated systems, and consulted with the University of Delaware world-renowned solar energy department.  We were really nuts.  We finally decided to supplement the limestone floor's rock with 30-gallon black metal drums filled with water.  This, we hoped, would prevent the seedlings from freezing without adding a fossil fuel heat source.

It is not a trivial task to find new, clean 30-gallon black metal drums.  After many phone calls, one company referring me to another, I hit pay dirt when I found  a small vendor in New Castle, Delaware who had these available.  I made 3 trips to and from the vendor, loading 2 drums at a time into my trusty station wagon.  I filled the drums with water, adding 5% bleach to prevent mold/mildew/algae, placed 3 under each of the 2 benches, and waited for the thermal magic...and waited...and waited.  I monitored the freezing temperatures...and waited some more. Note to self:  there isn't enough sunlight in the world to heat 30-gallon drums of water to the point where thermal mass becomes sufficient to prevent freezing.  A call to the U Del experts confirmed that fact.  If I started with boiling water, then maybe it would have worked. I had not understood that the water needs to start out pretty warm to be able to give off heat.  It could not absorb sufficient BTU to raise the temperature above freezing.  At most, I got 2 degrees of stabilization from the drums.  They were ugly, took up space, and pooled water on the top.  For 2 degrees, this was an unfavorable equation.  Away they went, and with them any hopes of a solar-friendly nighttime temperature equilibration paradigm.  All was not lost, however, as I now understand why Florida citrus farmers spray water over the crops when they are in danger from an unexpected frost.

The Greenhouse

When describing the complexity of the greenhouse infrastructure it's important to tell you about Joe and Paul Orpello from Moonflower gardens. I had interviewed several major landscape contractors when the garden was in the planning stage, but none shared my vision, and all thought that this was a small, not-important job. Not so for Joe and Paul. They are brothers who are trained in horticulture and have serious landscape design and build experience. They are not, however, jaded. As they pulled up in their little red truck, and waved to me in unison through the window, I was struck that they seemed adorable! They were excited about the project, and wanted to be able to provide an aging gardener with the ability to keep playing in the dirt for many years to come. In short, they shared the vision. At the time, I had no way to know that Joe and Paul are even more compulsive than I; they spent 8 months on the garden building walls, trellises, and the greenhouse. Joe and Paul became members of the family for those months, and remain available to help if needed. I can't thank them enough!

The greenhouse is a simple Cambridge model from Charley's Greenhouse, green aluminum and plexiglass. We evaluated many vendors, materials, and models to decide among wood, stone, etc. At the end of the day I decided on a green metal and plexiglass model for ease of cleaning and cost. Although I would have preferred an imported English stone and wood model (you know the type, and who wouldn't?), it was simply an unreasonable choice for a first-time greenhouse owner. As you read this you should be developing a mental model of a gardener who obsesses over every single decision, excessively. I excitedly awaited the arrival of the greenhouse.

Paul and Joe laid a foundation of large limestone slabs (for thermal mass, about which you'll learn a lot if you keep reading). The greenhouse has benches on both walls, and a complicated drip and mist system. There are electric outlets along the walls for heat mats, fans, etc and up-and-down misting heads. The original plan was to use it only in the Spring and Fall, so as not to need a heater. My wonderful electrician (Belfiore, Kennett Square PA) spent hours and hours installing a breaker box, enough juice for all future eventualities, underground lines to a garden A/C box, and an overhead light so I can garden at night after work. Joe and Paul recruited a plumber friend to add a greenhouse plumbing zone in the basement and to dig an underground trench from the house to accomodate the water pipes. This is one industrial-strength hobby greenhouse.

Spring has Sprung

...the flowers has riz, I wonder where the birdies is? (attribution:  my mother who is extremely odd, but in a nice way).  

The first thing I did this season was Spring cleaning in preparation for seed planting. This year, the third garden season, the greenhouse required a serious washing-down of the walls and surfaces.  How to do it, what to use? The vendor (www.charleysgreenhouse.com) didn't have much to say about the best way to clean.  The panels are plexi-glass, so I didn't want to chemically cloud them.  I googled my way to cleanliness, and decided upon Joy in hot water, followed by a plastic cleaner/shiner.  Cleaning the greenhouse walls and roof is a good example of something to which my rusty shoulder joints will object.  I had the good fortune to meet a lovely young U Del student through Craig's list, who agreed to spend an afternoon cleaning the greenhouse for me.  As it turned out, the temperature was 70 degrees that day, and I had a serious case of Spring fever.  Consequently we worked side by side, and I now have a spotless greenhouse. We were finished by lunchtime and enjoyed a wonderful first-outdoor-meal-of-the-season with him discussing economics and finances, his majors.  It was nice to have a youngster around, as mine are geographically undesireable (read=live far away).  Note:  (1) Joy in hot water, applied with a BIG sponge is an excellent cleaner; algae and dirt instantly vanished.  The pipes, surfaces, and plexiglass look as good as new, (2) only a seriously OCD gardener would both clean the plexiglass and polish it.  I planned to use Brillianize on a soft cloth (www.brillianize.com), but found that it was more trouble than it was worth --- it made no visual or protective difference (anyone need 2 gallons of Brillianize?).

Visual Introduction to the Garden

The garden is pretty much a big square. The only 'flat ground' remaining is to the right of the greenhouse, where I plant daffodils and tulips in the Spring, and Sunflowers in the Summer. I recently had a lot of fun using my rototiller (electric powered, very spiffy) for the Sunflower beds. The garden has 4 raised stacked-stone beds, topped with slate caps. The general idea about the beds is that they are (mainly) seat height, with the general idea that, depending on my overall creakiness on any given day, I can sit on the wall, lay on the wall, lean over the wall, or sit comfortably in a chair and point to the work that my husband will do. The beds are served with a drip and low-flow irrigation system that's pretty slick. I make use of free-standing pots and containers, and just love tripods, tuteurs, and obelisks - in fact, I love any kind of garden gizmo.

An important part of the garden is my little red wagon (noted to the left of the greenhouse). This is used, basically, once each year at the local garden club's sale. Others wait in line for the few carts that the club provides. I load my trusty red wagon (with the drop-down front) into the back of my station wagon, pack it up with goodies at the sale, and put it back into the station wagon fully loaded. It's very efficient and, in the company of my broad-brimmed staw hat, I look like a certifiable (haha, pun intended) gardener.

The Garden's Background

I guess it's will be helpful to explain how my garden came into existence 13 years ago because it illustrates my learn-as-you-go approach.  That would be the 'old' garden; the one that was overrun with smartweed.  We built our house 13 years ago, but ran out of money when it came to laying the sod (why sod, not grass seed?  That would be due to our energetic Labrador Toby, who is now tearing up the grass in heaven).  We decided to keep a part of the side lawn for a garden.  The native Longwood soil is pretty heavy, mostly  clay. One day I ordered, by phone, 15 yards of topsoil and 15 yards of mushroom soil (Mmmm, love that smell).  I figured that my husband and I could shovel the dirt onto the garden where needed .  When a tractor trailer pulled into the driveway I realized that my strategy was profoundly flawed.  I ran into the house, and found a rental company that would deliver a front loader that afternoon.  I had the time of my life moving a mountain of dirt into a flat, gently graded garden.  Alls well that ends well.  I love heavy machinery! 

Here's why I need a blog

This flower is tall (4 feet) and beautiful.  It's full-leafed; blooms in late-May to June.  I started it from seed and no longer have the foggiest idea what it is.  Can anyone help?