greenhouse


So I have this new small greenhouse, and now I have room for about 32 trays of plant starts instead of the 12 that I could fit in when I was using only lights in my basement.   Maybe I should have just bought more lights.  Check out the photo below.

5 trays of zinnias

5 trays of zinnias

The front-most tray has Benary’s orange zinnias.  The next three back are Benary’s scarlet, mix, and yellow zinnias.  The back-most tray has Oklahoma mix zinnias.    They were all planted at the same time, but when I moved the zinnias to the greenhouse, the orange ones got left under the lights because there wasn’t room in the greenhouse.  Look at them now.

In my previous state of ignorance, I would have expected just the opposite, thinking the zinnias would just love the greenhouse and the ones left behind would sulk and fail to thrive.  Nope.

As I mentioned two posts ago, I’ve had trouble keeping the greenhouse from heating up into the 90s (F), whereas the basement is a pretty constant 70F.  I suppose that must account for the difference.    Unless Benary’s orange are gigantic compared to the other colors.   I kinda doubt that.

I’ve found that the hardest thing about my small greenhouse is keeping it from getting too hot inside.  Even with the end door open, it is often 80 – 90 F inside on a sunny day, which is way too hot for the seedlings I am trying to raise in there.  I made a simple vent out of a couple of scrap 3/4 inch pine boards that I sawed into narrow strips and screwed together along with a spare piece of greenhouse film.

Basically, it is made of just two rectangular frames, one frame an inch bigger on both sides so it can fit around the smaller one.  The bigger frame is covered in plastic.

Frame has been screwed down.

Frame has been screwed down.

The small frame was screwed down to the greenhouse frames on top of the plastic film.  The film was then cut, wrapped around the sides of the frame and stapled.

Vent2Vent3

The bigger frame just sits on top of the smaller one.  There are no hinges.  I just lift it off and slide it in through the opening on sunny days.  I will probably need to hold it down somehow, maybe with a bungee, but that hasn’t happened yet.

The top frame with plastic

The top frame with plastic

Finished

Finished

There are lots of happy plants in the green house now, and a few …  ehhhhh, not so much.  My purple majesty millet is getting pretty big, but I think it needs a little somethin’.  A lot of its leaves are pretty pale looking.  I gave one tray a quart of diluted fish emulsion for a perker-upper to see what happens.  Jeeze, is that nasty-looking stuff.  I had a septic tank pumped out once and the resemblance is strong.

Getting kind of full in here

Getting kind of full in here

I’m also having an issue with my digitalis.  Some of the seedlings are scrawny and struggling, with pale leaves and green veins.  I sought some help with this and my problem may be (1) It’s too hot for them in the greenhouse (2) They are lacking iron (3) I’ve kept them too waterlogged and the little beggars are drowning (4) Some combo of one through three, or (5) Something else.  I gave them a shot of iron, and am trying to keep them cooler and dryer.  So far most of them still look like little sad sacks, though one is quite big and healthy-looking.  Odd, huh?

How nice that it is good and truly spring now in the north country.

Now, two weeks later, there really is some green to look at.  You can see spinach in the bucket along with digitalis camelot, knautia, blue bedder salvia, and dianthus amazon in the trays.

greenhouse331

I have to confess that I’m really growing these under lights inside, except for the spinach, and just bringing them out in the greenhouse for short periods of time.  We are still having nights in the 20s and I can’t trust my water buckets to keep it from freezing in there.  According to the maximum/minimum thermometer I have in the greenhouse, it has gone down to 30 right on top of the buckets a couple of times.  I believe that the water in the buckets is just not getting very warm during the day.  I could add a little heater at night.  I’ll have to do something soon, since, as of today, I have twelve flats of plants started, which uses all the room I have under the lights.

It’s not much, but it’s a start.

Two trays so far

Two trays so far

There are twenty-two 5-gallon water-filled pails wrapped in garbage bags to act as heat collectors.  Thanks to Nell for the garbage bag idea.  It’s 45 F outside right now and brightly sunny.   I have the top half of the outside door open , and it’s still 90 F inside the greenhouse at shelf level.  The tray on the floor has dianthus seeds planted and the soil temp in it is about 70 F, which is a little warm for those seeds according to what I have read, but what can I do?   I guess I could set the tray out in the snow.

The tray on top of the buckets on the right has some foxglove seedlings that are close to two weeks old.  I have them under the shelf to shield them from the sun a bit, as I started the little guys under lights and they are probably pretty tender.  In fact, I should probably go move them back inside.  Hold on a minute, OK? …

I’m back now.  Here’s what they look like.

Digitalis Camelot

Digitalis Camelot

I also have a few spinach plants growing in a bucket to see if we can get some early greens to put in our salads.  They’re also about two weeks old.

Spinach

Spinach

It may be only a start, but after a long cold winter it feels great to have green plants again, not to mention ninety degrees.

I just finished building a small greenhouse that I plan to use for plant starting in the spring.  I think I overbuilt it a bit, but I was concerned about the snow buildup this winter.

I started with a frame of pressure treated 4 x 4s and beveled them on the end because I plan to drag the greenhouse to another location next summer when I’m done with it.

Base with corner braces

Base with corner braces

Base with beveled end, the better to drag it

Base with beveled end, the better to drag it

I decided to go with a 12/12 roof pitch to help shed snow and five foot sidewalls to give me just enough headroom in the center.   After cutting thirty-six plywood gussets, along with studs and rafters, I laid each set out on my basement floor and nailed them together.  Okay, you probably see the screw gun sitting there and are thinking I didn’t really nail them.  I screwed the first one, but the rest were nailed.  It was faster.

One of six frames

One of six frames

Some time later, the six frames were built and ready to go.

Yep, count 'em ... six frames

Yep, six frames alright

A few days later I got the frames screwed to the base and braced.  It’s important to have the diagonal braces if the greenhouse will be free-standing.  Without them, the frames can tip over end-wise like a bunch of dominoes.

Starting to look like a house

Starting to look like a house

I messed up in calculating the roof rafters and somehow missed the correct length by 7/16 of an inch.  As a result, the sidewall studs are not exactly parallel to each other.  Can you tell which way they are off?  Leaning in at the top or out at the top?

Tilted sidewalls or is it just the camera?

Tilted sidewalls or is it just the camera?

With a little help, I got the 6 mil greenhouse film placed on the frames and fastened it down.  It’s supposed to be good for about four years.  See the channels at the bottom with the wire-spring things inside?  Well, probably you don’t in this picture, but click on the picture for a big version and you will.  I had heard that the wire-spring stuff was called wiggle wire, and when I tried to put it in, I found out why.  You have to wiggle the wire, first up, then down, then up, then down as you work each  bent section into the channel.  It went pretty fast, once I was on to it.  Maybe I would skip it next time though, to save some money.

I like it!

I like it!

The white material on top of the rafters is some kind of packing material that I had lying around.  I thought it might protect the plastic from abrasion against the two by fours, and it was a lot cheaper than the felt tape in the greenhouse supply catalog.  I suspect it is going to mildew eventually.  Sigh, I wish I would have done a less ugly job of cutting and installing it.

In order to hold the plastic around the door frame and the frame against the house, I used two strips of wood, each 3/4″ by 3/4″.  One was nailed to the frame and the second was screwed right next to it with plastic trapped between them and under the second one.  I just pulled the plastic tightly across the first strip and pushed the second strip into place and screwed it.

Here’s a closeup of it.

Over the left strip and under the right one.

Over the left strip and under the right one.

To seal against the house, I cut pieces of foam.  It’s called sill seal and I think I paid five bucks for a roll at Home Depot.

Not pretty, but I think it will work.

Not pretty, but I think it will work.

I covered the shelves with galvanized metal lath that you can buy at any building center.

Inside

Inside

I made the door from 1 x 3 stock, fastening the pieces together with pocket screws.  The top panel has acrylic plastic, but I cheaped out on the bottom with a piece of styrene fluorescent light cover.  Bad idea.  It cracks really easily when holes are drilled in it.  If it fails, I’ll spring for acrylic, which will no doubt happen in the dead of February.

And now it’s done.

Hey, it's a greenhouse!

Finito

It’s a bit on the homely side, but should do the job, I hope.  The materials cost about $280, which seems like a lot, now that I think about it.    Really, though, I suppose it’s pretty cheap for a fifty square foot greenhouse.

I will be putting a bunch of black water-filled plastic five gallon buckets inside to act as a heat absorber and radiator to see how that works, solar energy-wise  Unfortunately, I have only white buckets and black paint probably won’t stick to the polyethylene very well.  Still, I will try.

Update January 9, 2010********************

The greenhouse has been doing well for two years, but I really need more room for plants.  I decided to bump out both sides, leaving the base the same size.  As it turned out, the rock wall on one side kept me from expanding in that direction, so I settled for a one-sided bump out.  I hope the greenhouse doesn’t tip over when I fill up that side with plants.

All I did construction-wise is to extend the rafters with 2 x 4s and run more 2 x 4s under the plant shelf to meet the extended rafters.  I didn’t think to take any pictures of the process, but here are a couple of photos to show how it ended up.  It now looks like a backward 4.

I think the homely factor has been bumped up too.

More room!

I’ve now doubled my space, though I’ll be able to keep only short plants on the far side of the new shelf.

TM

New development – 11/15/2013 – I’ve redone this greenhouse to make it bigger and posted it on a second blog that I use now for posting.  See it here.