Starting seeds in greenhouse

I am going to try first time to start seeds of some flowers using my new greenhouse. Actually, i am planing to start them inside and then move to greenhouse because i don't have electicity in greenhouse to use lamps or heater. Anybody knows when seedlings can be put in greenhouse and be there without lamps? March? February? or only April? I am not worried about cold at this point, just light.

Briergardener - Are you putting seedlings in the greenhouse that were started indoors in the warm? If you are transferring them, you may want to give them a bit of protection at night for a few days just to help them acclimate (I assume these are all hardy plants, not tender annuals that you are putting out) - a sheet of newspaper or something light just to keep any frost damage off. Be sure to remove covers before sun gets to green house in AM or you will get moisture building up and increasing the weight of the cover which might break the seedling. I would use the cover for a few days to a week depending on growth.

if you are starting the seeds in the greenhouse (again hardy annuals, hardy perennials etc.) then they can go out straight away.

brier, if you're starting seeds indoors then transfering them into a unheated greenhouse below 40%f they will stop growing and it can take 6 weeks to break dormancy. when I start plants indoors under lights I time it so when i move them out in my unheated greenhouse that the minimun temp is 40%f so they don't go dormant on me. I've been starting my Tomatoes, Zinnias etc. in April indoors. good luck, Jim

I use greenhouse heat pads under my seed starting tray. Warms up the soil to about 70 degrees so the seeds will germinate and sprout. I will be starting my summer veggie and flower seeds around Valentines day. This will give them a good two months growth before I would even considered moving them outside or to permanent locations. I live in Astoria, Or , zone 7b. But since I live 15 miles east of town, I get colder winter nights and hotter summer days by as much as ten degrees from Astoria. I do use a portable heater in the greenhouse if the temps are going to drop into the 20's like what we have been having lately. But it's starting to warm up again so the snow is melting and temps are returning back to 40's daytime and lower 30's nighttime.
Joyce

What about onions? Should i start them now in greenhouse (not heated) with pads or should i start them inside and then move to greenhouse?
I usually start tomatoes end of Feb to plant outside in May (with cover). This will be first spring i have greenhouse and i trying to understand how to use it.
Thanks everybody for tempreture suggestions. I want to try in greenhouse my wall-of-water system: plastic jars filled with water, i usually put them around tender plants when i plant them outside early, then i cover plants and jars with row cover and plants like it.

What about light? Do i need to use lamps in greenhouse in March?

Hello Brier,

Onions need to go into the ground directly since they are a root crop. You can find onion sets (small onion bulbs) at your local garden store. Early spring planting for summer harvest depending on variety. Lighting: I use shop light sets with grow lights bulbs instead of the standard florescent lights that come with them. I use them to extend my daylight hours for my summer plants like tomatoes, peppers, etc. I like to give my plants 12 hours of light so put them on timers to regulate them. I also find that they can be hung just over the seed flats to give some gentle top heat to the soil and then raise them up a few inches at a time as the plants grow. See how I grew flowers and tomatoes completely inside a spare bedroom in my house with no sunlight source! I had gorgeous plants blooming and tomatoes in gallon size pots for our April Master Gardener sale. Here is the url to download my seed starting guide which chronicles that experience. www.virtualseeds.com/SeedStarting.html Click on the E-book cover to download the pdf file.
Joyce

Hello Brier,

Virtual seed recommends putting onions directly in the ground. This is true for sets or transplants.

However, if you are raising your own transplants, you would start them inside as early as Feb 1.

"Growing Vegetables West of the Cascades" recommends raising transplants for earliest scallions and biggest bulbs.

In February or early March, sow seeds 1/2 inch deep, eight to twelve seeds per inch, in rows 21/2 to 3 inches apart, on a 2 inch deep flat.

Sprout seeds between 60-75º. Grow at 50-70º in the day, 40-50º at night.
Do not thin.

Every few weeks shear tops back to about 3 inches tall. (promotes thicker stems and better developed root systems.)

Indoors, grow onions with at least 14 hour day lenght to prevent premature bulbing.

Harden off in cold frame (I am thinking unheated greenhouse could serve as same) in mid April

Prune tops again just prior to transplanting outdoors in order to reduce stress on root system.

Transplant when stems are about 3/16 inch diameter, or by May 1 at the latest.

Onions transplant very well bare-rooted, so separate the individual seedlings by shaking them apart or washing them in gently running water.

These instructions are from "Growing Vegetables West of the Cascades" by Steve Solomon

I am raising my own onion transplants for the first time this year - previously I have only used sets or purchased transplants.

Good luck!

When you say 'lamps' what do you mean? Are you talking about growing lamps - or lights just for illumination so you can stay out in the GH after dark?

I meant growing lights. I am looking at onion (i have "walking" onion planted last fall) that started to grow right now in my garden and am thinking that possible my onion seedlings in greenhouse will have the same amount of natural light as this onion and possible they can be without growing lights.

briarGardener, I've taken the top sets of my walking onions and seperated them then put them in flats in my unheated greenhouse until spring and then planted them out. I didn't need extra light, jim

Hi Brier,

To grow onion transplants you will need to provide light, at least 14 and up to 16 hours per day.

I am growing walking onions too, that I planted outside in the fall, but planting bulbing onions from seed is a different matter.

If you buy sets or transplants, you can just plant them directly in the garden in spring.

Thanks essentialplanet for the info. I have never started onions indoors so this was new information for me! I love Steve's book. It's a staple in our household. I am going to talk my hubby into making a few square beds for square foot gardening this year. I think getting plants into raised beds will help me be more successful. Here in this micro climate we have issue with cold wet soil until July. Getting the planting areas elevated will help warm up the beds sooner and assist in drainage too. Joyce

What wattage are grow lights? Do they use much energy? The only ones I am aware of over here are for the big industrial growers that are used to extend the day? I'm just wondering about non-essential energy use for 14-16 hours a day. Hmmmm, would make me think long and hard. I don't think I have seen them used for non-commercial growers. (Well except in the film Saving Grace - but then I guess that would be considered commercial growing. Funny film.)

Thank you, Essentialplanet, for information. But when you are talking about light for 14-16 hours, does it mean that seedlings have to be in greenhouse under lights for all 14-16 hours or lights should be turned on to give additional light before sun comes?

Laurie, what about tomatoes? Are you growing them without lights? I have small light stand, but before i was using it only for tomatoes. This is first year when i want to try to grow onions and first year when i have greenhouse, trying to learn.

Brier, I think you are doing a good job learning - you are generating a lot of discussion.

I'm not crazy about onions, I have a tendency to use leeks instead - I grow both leeks and tomatos in the greenhouse - no grow lights. I do have a small propane heater to keep the greenhouse at frost free and that is assisted by putting up blisterwrap on the inside of the roof (I have been using the same bwrap for 7 years - really lasts - and if you don't want to buy it, it is very easy to accumulate lengths). I don't start tom seeds until mid Feb.

Leeks I have no problem with starting in mid/late jan. so that I don't have to disturb them when planting out, I start them in cardboard toilet paper rolls - sowing the same as for a pot. When planting out just dig a hole, deeper than the roll depth, drop it in, and then cover over leaving only about 1 1/2" of green sticking out. The leeks take off in no time and the paper just breaks down. If you stand the paper rolls on end in a deep tray or cut down box, packed tightly together you can sow as many as you want and they stay snug and upright until you are ready to set them out. I think you could use the same method for starting onions.

Laurie, what temperature is in your greenhouse when you start tomatoes there in mid Feb? Just frost free? Are you using heating mats? Hm. i even did not think about starting tomatoes in greenhouse, was going to start them inside (sometime in Feb) and move them to greenhouse maybe after transplanting in bigger pots. Wow, looks like this year with greenhouse will be my year of new experience in everything.

Toilet paper rolls - good idea, i have to try it.Thanks

It varies Brier - yes, I do use a heat mat, and I sow my tomato seeds in long tom pots (the mat is kept at 16C (60.8F) - I do use bubble wrap across the windows at the back of the greenhouse (closest to the heat mat) once I start sowing HA (including veg). If you are planning on setting up a heat mat - may I suggest that you look at using a sand plunge heated with soil warming cables. Once it is to temperature it uses far less energy to maintain its heat. Once my heat mat dies, I am going to change over to that system. www.garden4less.co.uk/soil-warming-cable.asp

Sorry, I didn't answer your initial question - the temperature varies with the amount of sun during the day, Brier, but the important thing is it never goes below freezing - (I keep it at 5C - 41F)

May I also make one more suggestion - I loose laid a brick floor directly on sand over soil in my greenhouse. I find this has two wonderful features other than it looks lovely: in the winter it holds residual heat and in the summer it works like a swamp cooler.

This message was edited Jan 24, 2007 12:15 AM

This message was edited Jan 24, 2007 12:19 AM

Thank you, Laurie, i'll save your information. I need at first to connect my greenhouse to power supply to be able to use heating cables or mats.
But I definetely will create a brick floor.