Shade cloth is the standard way to cool a greenhouse in the summer. You should start with that, and then build onto the design with your PCM. PCMs are really neat, and they work 8 times better than water, but water is nearly free. I've always thought that a water-filled slab would make an even better floor if you could change out the warmed-up water with cool water at the flip of a switch. Maybe bury a tank completely underground, plumb that to the greenhouse tank, and just keep swapping the water back and forth. Then in the winter, you could use a simple solar heater to heat water, pump it into the greenhouse floor and that would provide your heat.

Hi! I'm GardenPaws, and I garden in the more distant suburbs of Washington DC. I've been gardening since I was a little kid helping with 1/8 acre of vegetable garden in Wayne Co NY, and have recently realized that the two kinds of gardens I'm most comfortable with are potagers and wild/native gardens. I like the potager concept because it seems to allow both more freedom and more design than cottage gardening. I'm redoing much of my yard to put permanent plantings such as berries and figs along the fence or house, then perennials backing lower edibles such as squash. mountainsong, your comment about tomatoes made me laugh, as most of mine form a loose hedge between my house and my neighbor's (we don't have a homeowners' association, thank goodness!). Mostly, I put things where they work, and then try to make them look good. I use strawberry Tristar as groundcover beneath an ash (soon to be replaced by a serviceberry), and those are backed, also, by daylilies and iris (which are backed by peonies). (The Earliglows get a regular strawberry patch - I'm too lazy to try to incorporate them into a design, but have arranged for snap beans to climb strings behind them.) As you might guess, I have a good many birds competing with me for the fruit, but there's plenty to go round now. I also deliberately plant things which will draw more of them into the yard - have a hummer coming to crocosmia and calibrachoa, and possibly to some of the salvias and agastaches, and we always have goldfinches feasting on the coneflower seed heads. Apart from my garden, I work full-time (wish it were otherwise), sing, write, and take dance classes. Nice to meet you all - thanks, diggity, for pushing for this forum!

I remember Spike, also. Live in a rented farmhouse a couple of miles from the freeway between Detroit/Windsor and Toronto, about half way between. Have had a garden for several years - biggest ever, this year ... over 3/4 of a mile of rows ... and the weeds are succeeding in getting ahead of me. Pleased to be in quite good health at over 80: son 50 nearby and daughter closing in on it, who, having dual ciizenship, has lived in Phoenix a couple of times over the past 15 years or so and now lives mostly with her partner who operates a motorcyle rental franchise on Cozumel, off the Mexican coast. If you click on our username, or the "My page" at the top of our post, you can find quite a bit of information about many of us, the ones who provided our profile. ole joyful

Wow! Sure a lot of people showed up for roll call. Good thing I decided to come back to visit after being absent for a few weeks. Please add me to your (ever-growing) list. Using the tv weathermen's lingo, I'm from SoCal. Thanks Minnie for undertaking this huge task. Kat