Growing out tomato seedlings in green house

[snappybob]

This year I was wanting to grow my seedlings in a green house. I plan to get them started inside under lights and then move them outside in the green house. I would bring them in if it was going to get too cold to manage the temperature in the greenhouse overnight or if we were experiencing really cold weather. My reasons for this are because I am running out of room inside and I am trying to get stalkier, stronger plants. I read an article on the web last year about how professional nurseries start seeds in warm conditions and then fairly quickly move the seedlings out into greenhouses for their sunlight but the temperature was fairly cool. I thought I had saved the link to my favorites but I can't find it now. Does anybody know where I might find this information.
Thanks

[kath]

The thread is called "Giving Seedlings the Cold Treatment" and was started by Ami in January of this year; http://tomatoville.com/showthread.php?t=13171.

I also have another one saved that can be found at www.kdcomm.net/%7Etomato/Tomato/start.html.
Hope this helps.

[alamo5000]

I live about an hour north of Houston and I have started, and grown my seedlings all in a greenhouse.

I never have used a grow light or anything at all, and we definitely get colder than you do down there in San Antonio.

All I do is at night make sure all the doors are all closed and I turn a heater on to avoid freezing.

Its the middle of december and right now I have 40 tomato plants growing in the greenhouse right now. Most of my plants are 1 foot tall in their containers...

The other 5 plants are full size because I started them earlier.... I have been getting fresh, red, vine ripe tomatoes recently...in December.

I think you are wasting your time starting them inside and/or using lights.

I invested in a $47 remote thermometer...all night long at any time I can see what the temps are....

A good $55 electric fan forced heater and my greenhouse has stayed above 40 degrees, even when the outside temps dropped to 24 degrees.

The lowest temp I had in the greenhouse was 42 degrees.

If you have a smaller greenhouse then your temps can go up, way up. My greenhouse is big....12 foot by 30 foot.... but I sectioned off half of it for heating purposes.... so 12 by 15 I can heat just fine with a single heater....

[snappybob]

Thanks for your input Alamo5000. Do you use heat mats for germination at~40F? What is your enclosure covered with? My enclosure would be rather small probably 6'X8' approximately. I'll be covering with a clear plastic sheeting over cattle panels bent over like a high tunnel. I am wondering if one type of plastic is better than another for light transfer. I would like to avoid using lights outside if possible. As for heat, most winter nights around here are 45-65F with the occasional cold snap where anything can happen.

[alamo5000]

I didn't use them to germinate all my stuff... but then again I got my plants all up and started before it started getting real cold. I imagine it won't hurt but I don't know if its nessesary.

All I did was go to wal mart and buy some of the small styrofoam cups and fill them with potting soil. I punched a small hole in the bottom with a nail then put ONE seed per cup. After that I put the cups in a clear plastic storage box (again from wal mart). I think I was able to fit 24 cups per box. It was important that it was clear because if its not then the shade from the side of the box will hinder things too much.

On a warm day I even sat mine outside in the sun from time to time... the tall sides on the box block the wind but they still got sun.

After a few weeks I transplanted them all to 5 gallon buckets where they reside now.

If on average you are getting down to 45 at night you won't have any problems. Heck, people up somewhere like Minnesota would think is spring if their nights were that warm.

If thats all you get then you can grow outside all year long most likely, however if you have a stray freeze then thats where the greenhouse comes into effect.

Where I am 90% of our winter days are good for growing. Its the cold nights that get you in trouble. We have been having 25 at night twice so far, with days being between 55 and 65 all day long...some days even have been up to the 70's.

I covered my greenhouse with a clear tarp, but for the size you are talking about you won't have any problem. Whatever frame you have (make sure its solid and anchored to the ground) and just wrap it a couple times with painters plastic from Home Depot.

For that small of a space, a small $30 fan forced heater will be enough and you won't need to run it unless the night temps drop below say 40 degrees or so. Just use a good extension cord.

Your target floor for temps should be maybe 45 degrees but 40 won't kill the plants at all, especially once the plants get beyond the intial stages of growth...

You would be smart to invest in a $50 remote thermometer too. I bought one online and you can see the temp inside the greenhouse anytime and it keeps a history of the high and lows. Mine even has an alarm on it... if it gets below whatever I set it on, it beeps...or likewise if it gets above what I set it on it also beeps...

During the daytime though you will definitely need to open up your greenhouse... the temps will get HOT inside there if you are not careful and you can cook your plants, especially little ones...

[hillbillyBob]

hummm good info seeing how I just north of you by about a hour or so, poured footers and slab for the new greenhouse yesterday what type are you growing??

[alamo5000]

You are about an hour and a half from me, kinda north east...

Right now in my greenhouse I have 5 full size plants left over from summer. I think they are Big Beef. I started them around August after I tried a fall container garden.

I also have about 5 mystery tomatoes. I think they are called "Black"... I ordered one thing but the company mixed up and gave me something else by accident. They of course refunded my money... but in the end the tomatoes tasted pretty good.

I have 35 Brandywine Suddith plants as well.

The latter of the two I started from seeds around Oct/Nov...now all my plants are waist high (except the big beef which is full size). Almost all of them are flowering out about now.

I also have two zucchini plants and a bunch of decorative plants. My mom didn't want to buy a bunch a new plants in the spring so she asked if she could stash her plants in my greenhouse.

[hillbillyBob]

Alamo what is the best early spring variety for our area??

[hillbillyBob]

I'm planing to start my first round of 2011 plants next week

[alamo5000]

Originally Posted by hillbillyBob

Alamo what is the best early spring variety for our area??

It depends on what your goal is.

If you are growing in a greenhouse...the world is your oyster around here. Just invest in a decent heater.

With a greenhouse in your arsenal your only real deadline is the hot july/august heat... its gonna cook your plants in the greenhouse or out of the greenhouse...

Last year I did early varieties and some mid and some late etc etc...

That was pre-greenhouse... yes I got tomatoes earlier, but the taste... blah. I wasn't impressed at all. If you are growing just for yourself and to give away or sell to the neighbors...thats one thing... if you are trying to sell large quanties thats different.

This year, I am not growing any early season tomatoes at all. All my plants are waist high on December 24th and blooming to beat the band...why you need early varieties if you can do that?

If you lived in Alaska and had a 4 month long growing season then early varieties matter a lot more. If you live in East Texas all it means is you are impatient and want more tomatoes sooner

Assuming you are just going to start your plants in the greenhouse and set them out in the ground later... if you start them early, like mid January or February and get a nice head start in some decent size pots... you can end up with late variety of tomatoes producing at the same calendar time you otherwise would be getting early varieties.

Me, this year I am growing for taste and a few experiment. I have no mid season or early season ones at all.

If you are growing in containers then you have about a 10 month long season (possibly) with a greenhouse. The only time its hard to grow is in the summer heat.

As for early varieties, if you are growing in the ground and not containers... start those all up around July 1 to July 15 (as seeds)...baby them so they don't cook or get too hot then later on put them in the ground for a fall garden about the end of August.

In my opinion early varieties are for a fall, in the ground (non container) garden (assuming you are not planning to grow full size plants in your greenhouse)...in Spring and assuming you plan right... mid and late season are the way to go.

In fall, at the very least you will have one last crop of tomatoes and/or a large load of green tomatoes for frying/making chow chow, or whatever.

I grow 100% in 5 gallon orange home depot buckets with soil bought from the local lawn and garden center although I might grow in the ground again in spring just for kicks and giggles.

[alamo5000]

Originally Posted by hillbillyBob

I'm planing to start my first round of 2011 plants next week

How big is your greenhouse? January 1 is kind of early unless you plan to grow in containers and grow the plants out inside the greenhouse.

If you are gonna do that, then why wait?

If you are gonna transplant them outdoors, I would wait until the end of January at the earliest.

Here is why: I goofed up and jumped the gun one year... I started my seeds like January 30th or so to Feb 15....my seedlings did great at first.... then they started to get bigger and bigger... and pretty soon they outgrew their containers...

The plants were big enough to set out, but I had another month until the last frost date.

I tried to keep on hanging on but eventually half of my plants died. Finally I just bit the bullet and set them all out and here comes another frost...I covered what I could and saved a lot of them... but it was a major hassle.

Transplanting plants 2 or 3 times sucks.

I use foam coffee cups loaded with good potting soil...put one seed per cup and put them in a clear wal mart bought plastic box. Clear is the only option. It lets light through, unlike those other kinds.

I was able to fit exactly 24 cups in one box. After they got the right size, I transplanted once to buckets.

If you start really early, I suggest using bigger... a lot bigger cups or foam bowls. It will give you the leeway you need to transplant a little bigger plant outside when the time comes... (if thats what you are gonna do). Otherwise you will transplant from one container to another container to another then to the ground... you are making extra work for yourself if you do that though.

My opinion is if you are gonna ultimately put the plants in the ground... its best to wait until the Jan 30-Feb 15 to sow your seeds...and use bigger cups or containers....

[alamo5000]

One other tip that I give newbie home gardeners that ask me... when you sow using my method put one seed per cup and plant twice as many plants as you ultimately want to have.

You can always give them away or throw them away. In the end you might not have 100% germination, or you might have a rookie mistake (I put miracle grow on my seedlings once and burned it to death)...

In the end if you get 90% success you can pick the most dominant 5 out of the 10 and grow those out.

Its not really that much extra work. You can grow 10 tomato plants with just a little more work than growing 1 tomato plant.

I had a girl in my office that was insistent on all she 'needed' was one plant. Well her one plant died. She could have just as easily grown 5 plants and had a little over run if needed.

I gave away more tomatoes and made more sauce that lasted me almost a year...but better more than enough than not enough.

[hillbillyBob]

yep I'm planning to do both containers and in the ground,I'm new to the greenhouse growing, and I'm in" East Texas all it means is you are impatient and want more tomatoes sooner" love to eat fresh tomatoes, time is about all I have left, I'm wheelchair bound the greenhouse will let me grow almost year around. So I guess instead of a early variety,I'll just go with a good beef steak type.
btw my greenhouse is 10x12 heated and vented, I'm looking into a hoop house as well, don't want this to turn into a bussiness, just a hobby

[alamo5000]

Originally Posted by hillbillyBob

yep I'm planning to do both containers and in the ground,I'm new to the greenhouse growing, and I'm in" East Texas all it means is you are impatient and want more tomatoes sooner" love to eat fresh tomatoes, time is about all I have left, I'm wheelchair bound the greenhouse will let me grow almost year around. So I guess instead of a early variety,I'll just go with a good beef steak type.
btw my greenhouse is 10x12 heated and vented, I'm looking into a hoop house as well, don't want this to turn into a bussiness, just a hobby

Well I can't think of a better hobby! If I get up around your way maybe I will drop in and lend a hand! Either that or you can be a proud peacock and show me your work...

I am new to the greenhouse thing too, but its my second year growing all in containers. Definitely. This is my first year growing in a greenhouse but I learned a lot so far. A little thing we call 'trial and error' up in our neck of the woods is a great teacher.

If you only want to use 5 gal buckets those orange ones from Home depot have been working for me. Don't use cheapy ones because they are not UV treated and will dry rot in less than a year. The orange ones I will get probably 3 or 4 seasons from them at least. And for $2.50 a pop that ain't too bad.

You can easily grow 10 or 20 plants in your greenhouse. Maybe 15 or so would be good to start with. Arrange some empty buckets inside so you can see how you can get around with your chair inside and still reach everything and then decide like that.

In all honesty 5 gallon buckets work great but if you are only doing a few plants (20 or less) you might want to invest in a collection of slightly larger containers. A 10 gallon container would be ideal in my opinion for any indeterminite tomato. Anything larger will be overkill.

As for heaters, I am using electric heat for mine, but evenutally I will buy a propane model as back up. Electricity is cheaper for you and my size and purpose, but one good storm and a pine tree across the power lines can cost you months of work. Daily, electricity...back up...propane.

The remote thermometer I mentioned before is definitely a MUST. Be mindful when you hang it up though. I bought a plastic covered foam outside faucet cover from home depot and hung the probe inside of that inside of the greenhouse. It looks like a plastic foam lined cowbell now. I was getting 100 degree readings before that. The sun was shining on the probe giving me false readings.

There are literally hundreds of ideas and gadgets and gizmos that will help out. I am growing zucchini plants in mine...and i was also considering getting a bigger container and making an asparagus bed too.

As for the early variety, all I am sayin' is the taste isn't what other types are (generally speaking). I have tasted some pretty good mid season varieties and definitely some great late season ones.

My tomato grow list for this coming up season is Paul Robeson, Cherokee Purple, Brandywine Suddith, Green Giant, and Brandywine OTV.

I am not messin' with cherries and all that this year.

Just go where your tastebuds lead you Your choices are literally endless. Read up about some good varieties and order the seeds online... MMM!!! If you do that though be mindful to order from a place with a good reputation and track record. I get all my seeds from tomato growers dot com. They generally give you pure varieties of exactly what you order (no monkey business) but when I did have a packaging (labelling)mix up they gave me a full refund.

It might be worth one season to buy like 20 different types of seeds and grow out 1-2 plants of each. That will be your baseline for deciding what is a keeper and what ain't and you will have a good reference point to work with.

[alamo5000]

AH! I have another idea... stakes...

At home depot they sell gray electrical conduit. Get a pair of PVC snippers and cut them off at 5 feet. When you load up your buckets with dirt put the stake down in it as you are filling them up.

Then transplant your tomato seedlings in beside it.

3/4 inch gray conduit is UV treated and for indoor gardening in containers its been working for me. Out in the wind and all that it might be different.

$1.19 for a 10 foot section. Thats .60 cents per tomato for a decent stake that you can use over and over.