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soil
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starting seeds in a greenhouse

does anyone out there start there seeds in a greenhouse? we have an unheated greenhouse that still gives us a good jump for starting seeds before we can plant them out.

how do you have your systems set up?

right now we have wide shelves above the beds(4 high, 18 inches apart) and they are 2 ft wide. there are gaps in each level to allow some light through. we can have a few thousand starts if need be but most of it is dedicated to propagation/overwintering plants.

i feel that the plants come out a lot more squat and sturdy compared to indoors even when the temps are warmer inside.
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organically_me
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I love starting seeds in my unheated greenhouse! I don't have to have starting mix in the house, the fan for air circulation is already there and ready to go, and light levels are great - unlike my seed starting endeavors in the house. The only drawbacks for me are, 1) watering those tiny cells several times a day on sunny days, and 2) uninvited animal trespassers who sometimes knock over my trays (my simple GH has no foundation, and plastic film for covering).

My setup is simply using 72 count planting cells, screened compost, a mister spray for watering (employing rain water whenever possible) and keeping the emergent seedlings just a bit on the stressed side, meaning that I'll cart them out in the wind, sun and cool just as soon as it seems like they can take it, for varying amounts of time depending on the harshness of conditions; then back inside for the night. I used to pamper my seedlings way too much, resulting in weak plants that demanded too much upkeep through the hot and dry summer months.

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soil
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My setup is simply using 72 count planting cells, screened compost, a mister spray for watering (employing rain water whenever possible) and keeping the emergent seedlings just a bit on the stressed side, meaning that I'll cart them out in the wind, sun and cool just as soon as it seems like they can take it, for varying amounts of time depending on the harshness of conditions; then back inside for the night. I used to pamper my seedlings way too much, resulting in weak plants that demanded too much upkeep through the hot and dry summer months.
we also use the 72 cell trays, lots of them lol. we also have 200 cell trays for the things that go in the ground fast, but usually have animal problems when very young( lettuces, onions for example) and a few others that i think are 140 and 120 cells.

i like how you have the mist system setup. we were considering putting in a micro sprinkler system above the plants on the underside of each shelf. hook that up to a pump run on a small solar panel because i really don't need to water on cloudy days. hopefully i can walk in, flip a switch and water the plants via overhead sprinkler, or hook it up to a timer when im gone.

i feel you on the babying plants, hardy plants grow much better when put outside.
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DoubleDogFarm
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how do you have your systems set up?
Shelving sounds like good idea.

This was my system for the last two seasons.

Seeding in open 1020 flats.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Greenhouse%20Photos/DSC01952.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Greenhouse%20Photos/DSC02039.jpg[/img]

Then pricking and transplanting to 4" pots. (18 ) pots to a flat.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Greenhouse%20Photos/DSC02031.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Greenhouse%20Photos/DSC02030.jpg[/img]

I've been using these display stands at the farmers Market. I'm thinking they would be good in the greenhouse.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Greenhouse%20Photos/DSC03095.jpg[/img]

Hand watering with a wand hose end or watering can. It's a pain.

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This will be the first year for raising seedlings in the GH, though I used it to harden off the plants last year.

I'm planning on using the Oasis Horticubes to start most of the seedlings in, though the plants I will sell will get transplanted into 72-cell trays. My GH is 16' long, and I plan on making the shelves almost two feet wide. Using just two rows, I can grow about 3200 seedlings.

By building the shelves, I can attach walls and line them with plastic, which will allow me to bottom water them.

Soil - thanks for the tips about the 200-cell trays. Will they work for Chard also?

Mike

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applestar
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Organically_me, about when can you start seeds? could you give me the actual month/wk as well as how far ahead of average last frost for your area?

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organically_me
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Applestar,
Sorry, but my record keeping regarding seed starting dates wasn't very precise last year. I have a thermometer set in the ground level soil in the GH, and one for air temps as well. When the soil thermometer shows that the soil is on a warming trend, and night temps are evening out is when I begin. I also will build a small (3' x 3' or so) compost pile in the GH when I start my seeds. The heat of the pile helps to control fluctuating nighttime temps. On a guess, I'd say that I started the first half of my seeds the second or third week of March. Plenty of light by then, and not too terribly cold at night.

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organically_me
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I forgot to answer part of the question. We usually consider May first to be our last frost date, so 5 or 6 weeks before that is when I usually start in the cold GH. (I did look back on my garden calendar for last year and there's a notation that we had a hard frost on May 10th, so May first is a bit on the short side.)

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applestar
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Thanks! Your answers helped me to narrow down the target dates. 8)

3x3 compost pile INSIDE, eh? That's a great idea, but does that mean your greenhouse is pretty big?

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soil
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doubledog we had a very similar setup the first year we had the GH, it was just hard to have enough for us to sell and grow. so in came the shelves! i don't mind the watering can personally.

wordwiz, they will work if you plan on putting them out fast. they outgrow the little containers fast. its basically to just make sure things germinate and you get plants out quick. they work good for herb seeds. the reason i use the 72 cell trays more is i can propagate small cuttings in them as well as start seeds.
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DoubleDogFarm
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I also will build a small (3' x 3' or so) compost pile in the GH when I start my seeds. The heat of the pile helps to control fluctuating nighttime temps.
Can you elaborate more on this. Will Allen ( Growing Power ) uses huge piles for large greenhouse. I'm interested in the smaller scale.
*******************************************************

Apple,
Try this "Create a Table of Estimated Planting Dates
based on your Last Frost Date" here at this web site.

https://www.dandello.net/garden/vegplant.shtml

about halfway down the page. Maybe useful.
********************************************************

Soil, yes I know what you mean. I moved out plants to make room for more.

Eric

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Soil,

I plan to use them (the 200 cell trays) only for lettuce and Chard. I tend to bottom water and use Tomato-Tone dissolved in water which provide very little N, but a good amount of P & K, so they grow slow but with good roots. I ordered their 5-pack so I can try a pack of lettuce seeds and see how they do.

Mike

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This will be the first year I am able to try seeds in the greenhouse. I usually start them inside. Last summer I built a 6x8 greenhouse in the back yard and covered with polyethylene sheets. Unfortunately the hot Va sun roasted the plastic and come autumn winds, the plastic was hanging from the rafters all tattered and torn. I have gone out and gathered enough old windows to cover the entire greenhouse, so sometime here in the next few weeks we will have a new beginning. However, The greenhouse IS unheated and the little bit of heat that the mulched bottom and water tank offer will only go so far. We'll see when it's time to plant the seeds. I suppose the thermometer will speak for itself. Anyone have any other ideas or suggestions on how to add heat for free?

P.S. solar panels don't count as I'd have to go buy those and at this time that's not in the cards.

wordwiz
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Nurse,

Once the seeds germinate, they will not need much heat - they will survive to the mid-40s, probably lower. You can use a heat mat to germinate them, they will need warm soil for that.

Mike

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GardenRN
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huh, didn't realize the could take the temp change after germination. Thanks! That helps a lot! I don't need heat mats because I have a setup in the house for germination. But being able to move them out to the GH after they get going would be awesome and help out a lot with hardening off as well. I bet it't make the plants a little stronger and more independent as well dealing with the cooler temps. The wheels are-a-turnin! Thanks again for the info!

DoubleDogFarm
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GardenRN,

Be careful with the transition. Don't just move them from a warm house into a unheated greenhouse.

Eric

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GardenRN
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will do, I'll probably do an abridged version of hardening off and try to move them out the last time on a warmer day. But thanks for the advice!

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organically_me
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DoubleDogFarm wrote:
I also will build a small (3' x 3' or so) compost pile in the GH when I start my seeds. The heat of the pile helps to control fluctuating nighttime temps.
Can you elaborate more on this. Will Allen ( Growing Power ) uses huge piles for large greenhouse. I'm interested in the smaller scale.
*******************************************************


Eric


Eric,
I found a photo. This is the GH at the end of the season, not the beginning, but I had no camera during springtime last year so it's all I have.
I built a roughly, 3.5' x 3.5' compost bin in the NE corner of my 10' x 12' GH. In approximately 6 weeks I'll start a *hot* compost pile with plenty of nitrogenous material in it to facilitate a quick start. It'll be plenty gassy for about 2 weeks but by the time I'm ready to start seeds it'll be decomposing rapidly, thus producing ambient heat. I'll use a fork to lift it a bit in the evening as I'm closing up the GH for the night. The introduction of fresh air into the pile at that time will help it to cook hotter overnight, thereby adding heat to the GH and saving me some worry about freezing nighttime temps. The most tender seedlings will sit on the planting shelf built over the compost pile; the warmest spot in the house.


[img]https://cubits.org/pics/2011-01-16/chelle/774ba0-250.jpg[/img]

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Re: starting seeds in a greenhouse

soil wrote:does anyone out there start there seeds in a greenhouse? we have an unheated greenhouse that still gives us a good jump for starting seeds before we can plant them out.

how do you have your systems set up?

right now we have wide shelves above the beds(4 high, 18 inches apart) and they are 2 ft wide. there are gaps in each level to allow some light through. we can have a few thousand starts if need be but most of it is dedicated to propagation/overwintering plants.

i feel that the plants come out a lot more squat and sturdy compared to indoors even when the temps are warmer inside.
. ++++you can even start them two weeks earlier that you ususlly do if you add 100 gallons of water in 50 gallon black drums and some smaller plastic 20 gallon plastic boxes. I suggest the dark green plastic containers with lids. the water serves two purposes it heats the greenhouse at night and absorbs some of the hot heat during the day!. As long as you have a double glass or plastic this will keep the temperature a few degrees warmer at night. the 20 gallon plastic containers will heat up faster duing the day and give off more heat at night. the 50 gallon drums will gradually heat up and stay about 50 once the real cold nghts are gone! I usually insulate the bottom of the barrels or plastic containers by setting them on top of a foam or insulated base which stops heat from being lost to the floor! Solar is the only way to go! Even a stack of bicks or block set on top of a inslated floor will absorb heat and release it after the sun goes down! I put my cole crops like broccoli on the table top above the water containers so they are cooled some on hot days so they don't get stringy!
I enjoy fishing ,gardening and a solar greenhouse! carpet installation repair and sales for over 45 years! I am the inventor of the Bobber With A Brain - Fishing Bobber!

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can anyone give me advice on what to do this year? Normally I start the seeds indoors under a light and then when they get a little too big for the tiny cells I transfer them to larger containers and move them outside to a little greenhouse. (this green house I built is garbage and I want to build a new one) and then I bring them in EVERY NIGHT. and bring them back out every morning. it is super annoying LOL! esp since I"m doing this usually when there is still snow on the ground.

SO... I'd like to build a sturdier GH with actual glass. I plan on using the glass from this thing we have outside in the back. it would prob be more like a cold frame type thing (low to the ground like). how can I heat something small like that so that I don't have to bring them in at night? is that even possible? I'd love to just start them inside and then move them outside for good once they're big enough to go into the larger pots.


I usually start my seeds March 1st. my plants are usually pretty huge by the time they're in the ground :lol:n but our growing season is pretty short so I like them to get a good start.

wordwiz
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soil wrote:wordwiz, they will work if you plan on putting them out fast. they outgrow the little containers fast. its basically to just make sure things germinate and you get plants out quick. they work good for herb seeds. the reason i use the 72 cell trays more is i can propagate small cuttings in them as well as start seeds.
Soil, an update. I sowed 120 super sugar snap peas on Jan. 26. As of this morning about 82 had sprouted, some within three days. There looks to be a few more about ready to break the soil. Some of the early ones are approaching 4" tall, which I presume is large enough to transplant.

Last year, I mixed up several 7-gallon pots of dirt, compost, and horse manure. I have a trench in the green house from where I buried hydro buckets and other containers in which I grew tomatoes. I plan on filling it with the stuff in the containers and once it thaws, transplant the peas. Based on the forecast, it may take a week or more which should really test the seedling tray's ability to sustain the peas.

Mike

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Chaesman
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Interesting thread.. Green House is suppose to arrive between the 8th (very excited about this) :P if I start the seeds in the green house do I still use trays? or do I just use cells and water frequently allowing to drain on ground?? Never used a green house before so this is all Greek to me

any advice is appreciated

thank you :)
Jon

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I don't have a greenhouse, but if I did, I would still use the trays. To me, part of the point of the trays is to be able to bottom water... pour a little water into the tray and let the soil soak it up as needed. I think it is much more effective than watering from the top and avoids a lot of problems.
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Chaesman
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Just asking becasue I have pleanty of 72 cell trays but no bottom trays at the moment and was just wondering if 2 or 3 daily waterings could suffice.. i'll get bottom trays if absoulutly neccesary but they are not in the budget at this point in time so I would have to do some money hunting lol. (Oh and when I say plenty I mean pleanty I have access to a local farmers supply and he has in excess of 100,000 cell trays
Jon

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Chaesman wrote:Just asking becasue I have pleanty of 72 cell trays but no bottom trays at the moment and was just wondering if 2 or 3 daily waterings could suffice.. i'll get bottom trays if absoulutly neccesary but they are not in the budget at this point in time so I would have to do some money hunting lol. (Oh and when I say plenty I mean pleanty I have access to a local farmers supply and he has in excess of 100,000 cell trays
You can use something like a Sterilite container to hold the water. Last year, I had about 40 trays of plants that I watered once a week. Took maybe 90 minutes.

Mike

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soil
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all of our seedlings are open bottom, most of the time i only water once a day, sometimes every other day depending on weather.
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GardenRN
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you can also use those aluminum oven trays...they are pretty cheap.

I have a habit of checking the dollar store first for something to serve gardening functions. Today I got 150 popsicle sticks for $1 for marking my seeds. I think one pack will be enough, and you can always come up with a dollar.

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soil
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. Today I got 150 popsicle sticks for $1 for marking my seeds. I think one pack will be enough, and you can always come up with a dollar.
haha i do that too.
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lily51
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Today I arranged all my seed packets by when they need to be started in the greenhouse, from Feb. to April. Otherwise, something will get overlooked or get way too leggy by mid-May.

Your method looks a lot like mine, using trays to germinate, then transplant. Some I start in the house, some in the greenhouse.
I like to grow the seedlings for a while under a grow light at a few inches distance to keep them short. Spindly seedlings do not do well.

Right now there are geraniums, petunias, hibiscus, dusty miller, heliopsis, rosemary, german statice, plus lettuce, spinach and radishes up. Tomorrow I'm starting some perennials and herbs. Love this time of year.

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You guys are all tempting me to do something! Anything! :lol:
I'm off to a slow start. I REALLY want to get some greenhouse sheeting and cover some of my raised beds with hoops this year for early start. 8)

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Chaesman
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Like I mentioned the greenhouse is going to be a whole new experiance for me. When I set it up ititially should I just leave the ground bare? should I cover it with a tarp or something? Eventually when my son pours concrete for his shop he plans on ordering a little extra to pour a slap for our greenhouse but what should I do in the mean time?

Boy am I getting excited :!:
Jon

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soil
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we got 200 free bricks from a building that was being torn down near us, we used that for the floor. i know people who just have gravel, chipped wood and those who use the ground to grow things in. the thing about the floor is you want it to have as much thermal mass as possible. this means in the winter it holds onto heat and in the summer it holds cool. this way the temps in the GH wont skyrocket in the day and drop dead at night( like most greenhouses people build)
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Chaesman
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Thanks for the info soil.. so a concrete slap that is in the works should be ample?? I'll just have to figure out something in the mean time.. Although wood mulch is only like 25 a truck load would that work for now or would the pests that come with it pose to much of a problem?
Jon

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soil
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you could always just leave it as the native dirt. nothing wrong with that.

the concrete should be fine.
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DoubleDogFarm
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The only thing I will add is crushed rock makes a good base for a concrete floor. :D

Eric

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My greenhouse has a concrete path down the center from N-S, then the rest is limestone gravel about 10" thick where the benches are. Works great.

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Mine is dirt and I like it. Found that if I am growing plants in containers or in hydro, I can bury them in the soil and help maintain a constant temp. I want to grow some peas, chard and broccoli in it starting this month, and I won't have to use containers. If I spill water, I don't have to worry about it - it soaks into the dirt and dries! I will never consider paving it with anything!

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My beds run east west. Not much of a floor more of an aisle. About 3" of crushed 7/8 drain rock.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Greenhouse%20Photos/DSC01954.jpg[/img]


Eric
Last edited by DoubleDogFarm on Sun Feb 06, 2011 2:20 am, edited 1 time in total.

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I put pieces of cardboard on the dirt floor of my unheated greenhouse. Periodically, after they become soggy, soiled and mangled, they go into the compost bin.

Last fall I tried a compost pile in the greenhouse and the results were disappointing. I created an enormous mess in there along with lots of flies. I'm tempted to try it again this spring but hopefully the snow will continue to fall here until that temptation passes.

For gardeners, this has been one of the most discouraging winters we've had in a very long time. We had two large snowstorms earlier this week and today's coastal storm was supposed to stay south and just clip us with a dusting. I just came in from shoveling 6 inches of very heavy dusting with no end in sight. Gosh, we need a break.
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DDF- so jealous of the setups in your pics. Still working on my greenhouse made of recycled windows. The frame is up and some windows are on! Just have to find time to finish more work. That and I think to make it fit right I'll have to take some panes out and make some of my own windows to go on the sides of the greenhouse.

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