Greenhouse garden plant seed germination

I am new to starting garden seeds in my greenhouse. I do mostly conifer trees and propagating tropicals, so when I found this group I wanted to jump in and ask questions. I read a few of the comments and found most of my answers before I even ask the questions. This is wonderful.
The links are great. I want to start some vinca, little red begonias and Impatiens and sweet peas. Where would you suggest I purchase my seeds? I need to learn the name of the begonias and vinca in order to be able to get what I need. That will be my next project.

Welcome to seeding JBerger! Plan to get addicted LOL. Seeds are available by trade or purchase online, at the garden centre or hardware stores. Just be sure that if you purchase seed it is fresh, ie. from the previous season. The date the seed was packaged should be on the envelope. Both lathyrus odoratus (annual sweet pea) and lathyrus latifolius (perennial sweet pea) do better sown directly in the ground. Plant the annuals as soon as you can work the ground. They like cold. Plant the perennials in the fall. Don't be disappointed if the perennials don't show up until the second season. That happens in my zone. Hope this helps.

I would say that the annuals that you mentioned prefer warmer weather and won't tolerate frost on them very well-begonias, impatiens and vinca specifically. I would not plant them outside until the nights are in the mid to high 40's-50's at the very least.

I would look at Park Seed for the seeds

I direct sow my annual sweet peas the first weekend in April. They get frost and snow in April and May and do just fine.

Hi, Tiger and Dahlia

I am going to start the seeds in the greenhouse and not plant them outside until May.
I want to start several flats for other people also and I am getting prepared to do that at this time. Tiger, it is good to see you in this group also. You have all been just wonderful to share information. I am waiting for a Park Seed catalog. That was my choice but I saw the name of another seed company below these comments and wondered if anyone used that one. Thanks again. I will keep you all posted. JB

JBerger-I don't know anything about the below seed company. I buy from the wholesale Park seed co and have for years and have never had any trouble and I would think that the retail side would be as good-I hope so! lol

Thanks so much for all your help and comments. I will keep you posted.

R.H. Shumway seed company is my favorite if you are putting out large market garden, 1 acre or more. Best pricing on larger quantities. They are on the 'net.

For the kind of things you are growing, you might take a look at Stokes Seeds. I've ordered from them for a long time and have found their seeds to be of very good quality. They have a lot of seeds for bedding plants such as you have described.

Thanks again. I will keep those companies in my file