Hello Paul
Can I suggest that you head on over to the winter sowing forum - better than the sowing from seed forum, where you will find a trove of useful info and easy ways of sowing many perennials without all the hoo-hah of using grow lights, heated mats and propagators (not that these are not useful, just not necessary). Right now is the time to start planning to get ready for sowing, especially those hardy perennials which need a slow stratification and hours of winter chill to break dormancy.

Thanks, I'll have a look. My only concern with ws is that I live in zone 2b and our temperatures can get very low (-50 celcius) and also can fluctuate rapidly from week to week. For example it's +2 today and will be -27 in a few days. Regarding my original question do plants, either annual or perennials, need to be potted up from the 72 cell for space or will they be fine where they are?

Thanks

Perennials that are hardy in your zone which you plan to grow from seed should adapt to winter sowing the same as those from perennials hardy to my zone. The winter sowing method is a natural, organic method that allows Mother Nature to take the lead and takes most of the guesswork out of growing them from seed.

Things grown via the winter sowing method tend to have extremely happy roots so the 72-pack cells likely are NOT deep enough to support top growth, nor do they provide adequate growing medium. Some gardeners prefer to plant seedlings directly into the ground; others (like me) pot them up to get some size to them prior to planting in my flower beds. If I've gone to all that effort, I figure it's in my best interest to give the plants the best chance of thriving once they're planted out.

That said, annuals grow, flower/fruit and die in the same season. They may or may not develop larger root systems than perennials. The link below will take you to the Missouri Botanical Garden where you can look up some specific plants by name and their growing habits.

Here is a link that might be useful: Missouri Botanical Garden

Do you need to pot up?
Depends on when you started the seeds and the amount of time it takes for germination. Also different perennials have different root systems. When I start annuals, tender perennials, or vegetables I sow seeds early enough that I have to pot up as think it gives the plants a bit of head start in our late cool springs. Once the roots fill the cell unless the plant likes to be root bound it will benefit from potting up.

I have found winter sowing to be the easiest method to start perennials and now only start those perennials inside that need extra attention or bloom the first year if they are started early enough.

There is a Far North forum that can give you a place to ask other Z1-2-3 gardeners about all aspects of gardening. Here is a thread about winter sowing, most were Z: 2 responses.

You can search for information on a specific subject by going to the bottom of the page and putting a subject in the search box.

And here is the Winter Sowing FAQ link:
http://faq.gardenweb.com/faq/wtrsow/

We in Z:4 also deal with the extremes of cold. Here is a photo to show it has worked for me. My yard is full of winter sown perennials.

Here is a link that might be useful: What Have You Winter Sown This Year and When 2011

I've done a lot of seed sowing indoors, including vegetables, annuals and perennials. I have never used a heat mat ever, and I've found that leaving the lights on 24 x 7 makes for bigger, stronger seedlings. I generally repot perennials and vegetables into larger containers and leave annuals in the smaller cells. You said 3 x 2 packs but then said 72 per tray. I didn't think the 3 x 2 equals 72 per flat?

The only thing I can advise is be sure you're ready to repot and have space! If you have a lot of success with the seedlings, once repotted, it's hard to find room under lights for everything. I keep all plants under lights until I'm ready to harden them off outside. As well as space, I've found at times I've been a bit enthusiastic as to how much I sow, and then realize the huge task of getting everything potted up! Look into a root fertilizer for strong roots.

Here's a pic of one of my shelf systems. It's one of those mini-greenhouses you can find at hardware stores, etc. that have a cover. I keep the cover draped over the back so when I'm spritzing early seedlings the walls don't get wet.

I have two sets of shelves that I use. One is pretty much empty until the repotting begins. Then I use both since all the pots take up more space. They're usually a 4-shelf system and I hang two sets of lights (and by the way I've never used really "special" bulbs. I mixed regular and daylight bulbs) under each shelf. I found if there wasn't enough light dispersed the seedlings got very leggy reaching for the light. Make sure you keep the light only a couple inches above the foliage and never let the trays dry out.

I've solely watered from above and have never had issues.

Back to the particular mini- greenhouse I use, I like them because they then pull double-duty when hardening off the plants.

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Make no mistake, lots of lights equals a definite increase in the electric bill. But it still costs a lot less when you can plant a few hundred perennials for those extra costs as opposed to purchasing them. Plus I just enjoyed doing it!

I have also done winter sowing and while so many folks on this forum have great results and their garden photos show it, I've never had that much luck. I usually wind up with very small seedlings and find I have to work very hard to keep them from drying out after planting. But I highly recommend trying both methods. Many years I sowed indoors and supplemented with some winter sowing for perennials whose seeds require stratification.

Good luck!

Can you tell me what size of lights that you use and how many bulbs with each light? Thanks

Shop lights are pretty much the standard. 2 40" bulbs per fixture. I've mixed daylight and cool whites, and have decided there isn't a difference between them. So I generally go for the cheapest. I have one 4 bulb fixture that I got for overwintering rose cuttings. It was a lot more money, and a certain amount of electrical expertise to set up.

The biggest thing to remember is to get the bulbs as close to the plants as possible. Fluorescents only generate heat from the ballasts, so there isn't any reason the plants can't grow up into the fixtures.

Thanks for all the great advice. So I went shopping today and bought a grow light and all the extras. I'm going to try both methods and see how everything turns out, I'm sure I'll make mistakes along the way but will keep coming back here for pointers. Thyme2dig your set up looks amazing and hopefully one day I'll get to that stage but for this year I'll keep it small and see how it goes. One last question, if my last frost date is may 25th when should I start perennials and annuals indoors, I know to be specific this will depend on the particular plant but is there a rough rule?. Thanks again for all the advice

I live in zone 3 and I start many perennials from seed. Some bloom the first year and others will only grow the first year and bloom the second year.. I grow my seeds in mushroom plastic boxes which have holes I'v put in the bottom. 2 mushroom boxes fit perfectly in the large clear plastic biscuit containers I bought from my local grocery's deli. 2 of these biscuit containers will fit on a 10x20 heat mat. They act as tray and humidity lid. I transplant them into larger individual containers before they go outside. Check your local dollar store for small styrofoam cups and put holes in the bottom. 48 of these will fit on a tray and they hold enough soil until you can plant outside.

If you have your light fixture over a table you can extend the light from your fixture by draping a mylar blanket(survival blanket--from the dollar store) over your fixture and securing it with something heavy. Make sure it can be undone so you can check your plants.

I start mine about 8 weeks before the last frost date. If you secure a piece of clear plastic over your bed 2 or 3 weeks before planting it will warm the soil and get your plants off to a good start.

If there is someone near you that has an established perennial bed strike up a gardening conversation with them. Let them know you are starting a new perennial garden/. Don't worry that you'll be intruding. Gardeners love to talk flowers and give newbies advice. You just may get some established perennials that you know will do well in your garden. I know I compost many perennials every spring that I have divided and I sure wouldn't mind giving them to someone starting a garden rather than composting them

I am curious, what grows in Z2?

"One last question, if my last frost date is may 25th when should I start perennials and annuals indoors, I know to be specific this will depend on the particular plant but is there a rough rule?. "

Paul, you need to be aware that a number of perennials will need a period of moist cold before the seed will break dormancy. Some though not all will sprout in response to being sown and sited someplace warm in light.

When you've chosen your plants you wish to grow, please look them up on one of the databases for suggestions on if a period of moist cold is required and its approximate length, how to help to break seed dormancy.

This one rates a bookmark, quite reliable....(and you would find the articles on sowing of interest too)

Here is a link that might be useful: Clothiers seed germination databases

I'm also curious about Z2. Saxifrages?

Here is a link that might be useful: Moving to AK, what can we grow?

It is very hard to do but try to remember that depending on when you start you will probably have to pot them up at least once and need room under your lights for this. I like to plant large plants outside so I plan on having them in 18 cells/flat at plant out date.

There is no general rule as when to start, unfortunately. My last frost date is the same as yours and I just started some of my slower growing cool weather plants this weekend (Pansy/Viola and some bulb onions for example). I also sowed some of my perennials and roses.

morz8 gave you a great list for perennial seeds. I also suggest looking at a site like stokes seeds and it will tell you when they suggest the commercial growers to start for bedding sales. It often gives you approximate transplant and bloom times as well as what size pot to expect in the given time frame. Also it will suggest whether the seed needs to be frozen etc. I have found the info they give to be quite accurate, YMMV.

If it was me I would start at least a few seeds of each now. It will give you practice and any mistakes won't set you back considerably. Plus you will know what to expect from each plant. And it is a fun way to break the winter blues!!!

SCG

Another good seed-starting calculator:

when to start seeds