You must harden off your plants before planting them in full sun.

I am afraid the "harden off" my plants is quite a bit beyond my knowledge level. Mostly I just wonder when the nurseries plant their seeds.

Hardening off means a gradual transition from the greenhouse to the garden giving the plant time to adjust to the dessicating effects of wind, full sun, and the temperature changes of night and day, it is vital to the survival and success of the seedling.

The nurseries very well could have started their seeds the exact same time that you did but with better hardening off practice their seedlings thrived.

rolacoy:

I have been gardening for many years. I start my seeds in my greenhouse, so here's a few tips for next year.

The only growing mix I use is the soilless promix BX. I buy it in the 3.8 cubic foot compressed bale and it costs less than $30. I grow a lot of plants and one bale lasts me for most of my planting for the season. It is the best planting medium there is.

The containers--I never and I mean never use peat pots. If you don't have containers, put holes in the bottom of paper, styrofoam or colored plastic cups. Raid the recycling bin for possible containers made of these materials--not metal.

Starting seeds--I really think you should read the seed starting FAQ's at the top of this page. There is just too much to say on the sunject for me to write it down. I'll just say that when starting seeds the seeds have to be kept constantly moist not sopping wet but moist. A humidity hood is a good thing to have. Once they have sprouted you remove the hood and let the plants dry a bit before you water again. Plants must be hardened off before setting outside. That means gradually over a week or 2 giving them a little sun then moving toward more sun each day.

Your greenhouse--You have to have some way of heating and cooling it. Too much heat will cook the seeds or plants and freezing temperatures will kill some too. A minimum maximum thermometer is a valuable tool. It lets you see just how hot and just how cold it got in there since it was last set.

Some seeds like your poppy are better off being sowed directly in the flower bed.

Growing from seed is a time consuming, learning process. Like anything else you undertake to do there is a lot to learn before you have sucess.

As I stated I built the greenhouse sometime in January of 2010. It was heated and kept above 50 degrees. The plants were watered regularly. You can see a picture of the greenhouse toward the end of my pictures. When I planted the seeded plants they should have been larger than they were, I think, at least when comparing them to the plants being sold in nurseries. I know the nurseries know more than I do about growing from seeds, that is what I am trying to learn.

When I planed my seedlings I planted some of them in the sun and some in the shade. Most of my garden is shaded by two big Oak trees, so I doubt that the plants were shocked by the sun. They were just little.

At what time of the year do nurseries plant their seeds?

Here is a link that might be useful: My Garden

Have you considered calling a nursery and just asking them directly ? I'm sure someone at White Flower Farms might be willing to talk to you, they seemed fairly customer service oriented when I had a question for them.

rolacoy,
commercial greenhouses do things on a completely different level than we could ever hope to achieve ourselves. They have many greenhouses, each set to specific growing conditions for separate types of plants.

Please read through oilpanter's post again and see if there might be something there that you could adopt to use next year. There is some very good advice in there.

I doubt that the plants were shocked by the sun. They were just little.
That is exactly when they are most vulnerable - Any quick or drastic change (even though it doesn't seem like much of a change to us, it is earth shattering to a seedling) to their growing conditions and . . . poof! This is why everyone gets so frustrated with the hardening off process - it seems to take forever but is a very, very necessary evil :)

You might also want to check out the Winter Sowing forum for next year, the no-muss, no-fuss way to do it.

Just my advice. You can take it or leave it as you see fit (that's the best thing about advice!). Happy growing! :)

Why are you so hung up on when nurseries plant their seeds?

When nurseries plant their seeds is an impossible question to answer. Some seeds can be planted as little as 5 weeks early and some seeds need to be planted months ahead of time. The info on the seed package tells you when to plant. Nurseries probably start theirs the same time that's recommended to you on the package or they may start theirs a week or 2 earlier than that but that's about all.

The nurseries know about plants and theirs are grown in optimal conditions too. Each variety is given it's best light, water and temperature and growing conditions for that variety. Some plants germinate at 60 degrees some require 80, Some like dry conditions and some wet, some like the shade and some hot sun.

The same when you plant them outside. You have to know which plant to put in the sun and which likes shade.

Planting out little seedlings is not a good practice. They need hardening off and a big enough root system to tackle the adverse outside conditions. A tiny root system and the plant will dies the first time the soil dries. Yah you say but plants do grow outside from seed. True but that seed comes up slowly and is aclimatized to it's growing conditions and with some seeds only a few of the seedlings will survive.

The long and the short of it is you have to learn what and why you are doing things and what each plant requires

That is what I am trying to do is learn. Thanks

When you start the seeds depends on what seeds you are growing, what your last frost date is, and when you want to put your plants in the ground.

Seeds that take three weeks to germinate and are warm loving, you need to find the date it is warm enough for the plant to survive and plant the seeds two months before that. This will give them time to germinate and grow before you plant them in your yard / garden.

Most seed packets will state when to start them inside (IE: 3 weeks before the last expected frost date) as a guideline. This will give them time to grow before you can plant them out.

Most nurseries have some people working there that have their own gardens and they can give you advise depending on what you are growing.

If you are planning on starting a growing business, Then you need to use the date you want to sell your plants and use that as the date instead of the frost date.

OK, Thanks. I will try to continue learning about plants and see what I can grow.

rolacoy
I had a terrible hardening off experience this year (long story). I lost probably 2/3 of my seedlings. I was going to give up on my tomatoes but I had 6 Early Girl that didn't die and put two of them in a raised bed with a hoop house two weeks before last frost date. They were only about 4-5" tall.

Two weeks later I bought some whoppers from the nursery. They were kinda leggy. I planted them clear up to their leaves in another raised bed in a hoop house.

Now it is 2 weeks after last frost. My early girl plants look as big as the nursery plants and I think they are healthier looking.

That was a long story to tell you that I too was envious of the nursery plants. They looked like they were weeks ahead of my sad little seedlings. However, when it comes down to it my home-grown seedlings are right along with the nursery plants now.

I tend to over-analyze stuff so I took my frost date, figured out that the hoop houses would probably buy me an extra 2 weeks. Then backed my planting date (recommended from the seed package) from the adjusted frost date.

One point about nurseries/garden centres which is certainly true over here, is that they will frequently get plants out on display far too early just to get the sales. You will see tender plants(in our climate) such as petunias and pelargoniums available long before it is safe to put them out in our gardens. They push the plants with fertilisers and light manipulation to get big flowering specimens to tempt the unknowledgable buyer. So don't worry too much about what nurseries are doing. Just try to get good healthy plants suitable for your own garden. They will make up the time if they are happy.

Flora UK

Petunias and peligoram Geraniums are not tender plants. Both will take a light frost.

The temperature of the soil is more important than the earliness. If the soil is cold few plants will grow well. Don't be afraid to put these out early if the soil is warm.
I find that big box stores and groceries tend to do that here, more than nurseries who grow their own plants