Pretty small, Susan. At least, for use in mild-climate areas, you can buy a tiny greenouse that is just a framework (which includes some shelving) with a plastic film outside, for very little.

And they work just fine.

If you need some sort of misting in there, we've found that one of those cheap patio misting systems works quite well, if put on an also inexpensive battery-powered timer.

Jeri

Here is a link that might be useful: cheap portable greenhouses

Also if you search free pvc designs, you can find a variety of easy to make pvc green houses

If honestly all you want it for is seed starting, there are much cheaper alternatives. I have several light setups that have produced a lot of seedlings over the years. Check out the Winter Sowing forum for another alternative.

Basically, it is hard to get much use out of a greenhouse without adding heat, and heat gets expensive.

It depends upon where you are, and what the climate is.

Our backyard greenhouse produces ample heat, provided by the sun. In the summer, we actually toss shadecloth across it, to temper the heat.

Jeri

Yes, but Nashville is USDA zone 6. They get real winter, like with frost and snow.

You might consider a hot frame, sometimes called a hot bed. You can heat them electrically or the old fashioned way with uncomposted manure, provided you know someone with horses or cows.

Rosefolly

Here is a link that might be useful: How to build a traditional hot frame

I agree with mad gallica. If all you want a greenhouse for is to start seeds, then look at wintersowing. It is a wonderful way to start seeds; it sounds bizarre but it is very effective. There is an active ws group on gardenweb and will teach you everything you need to know. It was very effective in Alabama.

I use it here too and am saving milk cartons for seed sowing.

For a long time, before I had my greenhouse, I used many ways of starting seeds and taking cuttings, ranging from using every windowsill in the house, often with silver foil reflectors, a small plastic greenhouse (as Jeri described), a small heated propagator with growlights to a coldframe outside (a timber box with glass lid). All these were perfectly satisfactory. Why do you specifically want a greenhouse? I grow bell peppers, cucumbers, aubergines in summer, overwinter many cuttings and sow hundreds of seeds every spring and autumn. The greenhouse takes up a third of my garden space so I fill it with vaguely tropical flowering plants and citrus over winter although I do not use extra heat. I make it work hard for me. But, before having one, my gardening activities were not really curtailled at all. I do not use it for anything related to roses - in the UK, they always do better outside at every stage of growth. So unless you specifically crave one for a very specific purpose, why take up valuable planting space outside. If you do decide to invest in a glasshouse, then get the biggest one possible because as soon as you do get one big enough to walk in, you will fill it up and think of many more things to grow. There is usually little difference in costs for an extra few feet. Mine is 8feet by 12 feet.

I'd really like to start seeds and don't have anywhere to start them in the house. I actually have looked at winter sowing but I didn't quite "get" the idea. Maybe I need to go back and look again. Most of the seeds I want to start likely need bottom warmth so a hot bed might be worth a try.
I'm definitely not considering glass...too costly for me right now.
Thanks!
Susan

Susan, you can buy a heating element that will provide bottom heat fairly cheaply on line.
(NOTE: You do want a thermostat, so you can control the heat.)
We used one for several years, in a rough cold frame, which sat on an old redwood picnic table, in a sheltered location.

Really cold temperatures are not commonplace in our winters, so it was a bit of overkill -- but it might be useful to you when temps dip.

Jeri

Unless you have a large family and a small house, there probably is somewhere to start seeds. For years, I started them on shelves under the television in the living rooms. Now it happens in the dining room. Spare bedrooms, bathrooms, basements - all of these work through the wonders of shoplights.

Susan, what seeds are you interested in starting?

thanks everyone for the thoughts and suggestions. i am interested in all the old cottage garden perennials and annuals:
mallow, dill, four o'clocks, crambe,lady's mantle, lychnis, agastanache, variety of nepetas, balloon flower, wallflower, bergenia, mugwort, cleome, petunia, lamb's ear, hyacinth runner bean, nigella etc.
Just about any good companion for roses. I have tons of bearded iris, daylily, sedum, phlox paniculata, clematis, tall nepeta, elephant ear.Some coleus or foliage plants...
It's hard to find interesting perennials and annuals here. Everything is cliche and tired or NEW and HUGE and IMPROVED and too garish.
I like the old fashioned stuff.
The online nurseries I've found that provide starts of what I want are just cost prohibitive.
I have a basement. I guess I can rig it up? Does anyone know a cheap source for seed starting mix/pellets etc?
Susan

Do you have seeds for your 4 o'cocks?

If I look I can probably find some yellow and pink. I have white and hot pink that I still need to plant.

My experiences with those I've grown.

mallow - self seeds around. Make sure you want it before putting it in a garden.

dill - same as mallow, but does have the advantage of being edible.

lady's mantle - grows slowly from seeds. Seeds around a bit.

lychnis - some varieties are weedy. Others are reasonbly well behaved. Easy to grow from seeds without any special care.

agastache - some varieties are very rot prone, and difficult in places it rains. Generally easy from seed.

nepetas - not a plant I would grow from seed unless I wasn't at all picky about what shows up. The selected clones are distinct enough that it is a good idea to buy exactly what you want, then divide for more plants.

balloon flower - currently very difficult to find seeds of the older, taller types. However, if you can find seed pods of what you want, they do grow reasonable true from seed. Easy, and will seed around if not deadheaded.

bergenia - tried this once and didn't get anywhere. Don't really know why, but it may very well be a bit tricky.

mugwort - weed, weed weed. Be very, very careful in introducing this one to a garden.

cleome - easy, will seed around.

petunia - will seed around once it is in the garden, but not the easiest plant to grow from seed.

lamb's ear - 'good' ones are vegetatively propagated.

Columbine is another good, easy to grow from seed, plant.

If there are plant swaps in your area, those can be good places to get the more common plants.

I would second the thought on mallow. I moved top soil that had been washed down the hill for years back up to the top of the hill and used in beds. This soil has had little green in it for years. But..add some water and presto! Instant rows of mallows popping up every where (feverfew too)

If you want something similar I would suggest hollyhocks. They spread too, but nothing like mallows.

I did however get all the mugwort out of the garden, so here, it is a weed but can be controlled.

I once had sweet peas crawling all over my living room floor that I started under lights when it was too hot outside to start them. Hubby didn't find it amusing. Larkspur are to me the loveliest old fashioned flower and can be started directly in the garden in what used to be called a scatter garden. So can poppies, baby's breath, annual phlox, Queen Anne's lace, cleome, gallardia, rudbeckia, cosmos, catchfly. All reseed every year, but larkspur will come back single flowers.

Ones I find do better in flats are lupine, hollyhock (Summer Carnival blooms first year and has gorgeous double blooms), allysum, nasturtium, viola, pansy, dahlia.

Common petunias are fairly easy to start, but the hybrids aren't and I also get a low sprout rate with snapdragons.

Thanks for the tips. Yes, I have to divide nepeta like crazy. I just wanted some of the different cultivars and trying to do it on the cheap.
My cleome doesn't self sow here...seems like the stuff that would really self sow (I mean 10 million seedson each plant of cleome) doesn't.
My verbena boniarensis does well self-seeding but that's it.
All my cosmos last year were consumed by aphids (they stayed off the roses thos).
I like starting in flats because I'm a control freak. HA...also because I don't have the room to just cast and sow.
Thanks again you all.
Susan

I've grown hollyhocks for years and have never started them inside. Just sow the seeds in late fall, and again if you like, in late winter. That results in waves of hocks coming up. After the first growing season, the hollyhocks will reseed, and you can gather seed, too, and sow the seeds in even more beds. I've also grown four o'clocks for years, and have always directly sown the seeds, usually in late fall. Morning glories can be sown in late fall or early spring, calendula is another...the list goes on. I used to atart seed on my washer and dryer many years ago, and grew the plants under a five foot grow light. It doesn't take much room, really. Diane

I have sown seeds and grown cuttings under 4' shop lights for about 40 years using one cool light bulb and one warm. The lights hang by "S" hooks on chains above my washer and dryer and the plants rest on shelves above the appliances. The chains and "S" hooks are so that the lights are adjustable but I never do. It is just easier to raise the plants on a box. Seedlings are started in foam cups (with a pencil punched drain hole and name written on the side) in an upside down sweater box, so that the base which is transparent is now the lid while the lid which is now the base has a small lip which contains watering overflows. I slip a milk jug cap between the two so that there is some air circulation and there you are. A friend adapted the idea by hanging the shelf from chains attached to basement rafters making the shelves adjustable while attaching the lights to the rafters. I hope you find a way to make this work for you because it is a lot of fun.

Cath

Much milder climate, but the hotbeds worked very well for me. I used landscape timbers (three widths high) or cross-ties (liked these best). I evacuated the soil within for several inches deep, filled with fresh manure & rotten hay, well watered in. If I wanted to sow directly, I topped this with the evacuated soil & a loose sandy loam.

Mostly, I liked to sow in flats or cells, or use the bed to root cuttings, so I often skipped the soil topping & nestled the pots into the rotten hay.

I used clear fiberglass panels for the top (or even just 4-6mil sheet plastic for my relatively mild winters).

The hotbeds worked well to overwinter brugs, hibiscus, citrus trees & other tender plants. For that, we staked pvc or used one of those aluminum slip-fitted car-port frames & wrapped these with 4-6 mil plastic. The plants were sunk in 6-8" & surrounded with the rotting hay. We never lost plants even through several pretty hard (for us) week-long frosts. In summer the sunken, compost-rich beds were great to hold potted plants that needed drought protection. With plastic removed, the bed was a well that kept the pots & roots cool & retained moisture.

These hotbeds also worked well to 'colonize' strips of clay into fine textured fertile soil for planting spring vegetables. Last season's hotbed/greenhouse shelter became next season's new raised garden bed.

The very simplest super-cheap hotbeds had hoops of pvc jammed into the bed sides & were covered with heavy clear plastic.

Hope this is useful. If you want 4'oclocks or lamb's ear plants, I'll be happy to send you some tubers & lambs ear pups.

These are all great ideas! I love the ingenuity. Bluegirl, I'd love whatever you can send me but can they be planted now in Nashville?
Thanks!

Cath, what medium do you use for the foam cups and how often (or at all) do you mist?
thanks!

In zone 8 (think ~SanAntonio area) 4 o'clocks are root hardy. The tops will freeze but the roots form enormous tubers that resprout. I have the classic fuchsia-colored plants.

Lamb's ear is evergreen (evergray?) & winter-hardy here. I can easily send both now if they're okay for your climate. Shoot me an e-mail now or in spring--happy to share. Have fun with your greenhouse/hotbeds.

I couldn't email you from the info on your page. My email is delta ice charlie tom alpha at comcast dot net

Thanks!
Susan

I e-mailed you. GW used to have an e-mail contact on member pages.

Susan,

Sorry for such a slow reply - I haven't looked at the forum in a while. The foam cups are the white throw away styrofoam cups used for beverages. I do not mist but start cuttings and seeds in an upside down sweater box with the lid (original bottom) propped up on a milk cap to provide enough air circulation to prevent mold - all very ad hoc but practical and quick.

Cath

I was thinking of you today as I was weeding all those mallows....

Only another 4 or 5 days more and I might be done.