Karen - I'd love to winter sow my petunias (or anything else for that matter, still haven't given it a try), but wouldn't the plants be awfully late for me here in the north that way? Our summer is pretty short as it is, I like to have them at least starting to flower around the beginning of June, and up through April we can be having really cold weather. Even so, might try doing some that way just to see, and it never hurts to have some later plants that haven't gotten all overgrown! I have had petunias come up from seed in the garden (where i emptied out my flower boxes the previous fall), so it would certainly be worth a shot.

I don't know, I've never gardened that far north. And honestly, I don't think I ever will! I hate cold!

Petunias usually germinate pretty early for me when wintersown, even in pretty cold spring temps. Here's some WSown Laura Bush June 15, 2009.


Maybe you should try a few next year. Nothing to lose but a few seeds...

Karen

>>Maybe you should try a few next year. Nothing to lose but a few seeds...<<

I've had some sprout on their own from dropped seed and bloom about mid-July. However, the one type (a double, frilled cultivar) that I tried to WS didn't germinate, so perhaps those are best warm sown. Or, it could be that the seed settled too deeply in my soil mix...I don't recall tamping it down firmly before tossing in the seed. I saved half the packet, so I think I'll try them warm this year and see what happens.

Who knows why? With wintersowing Mother Nature really has control over things. Maybe they were too wet, or too dry, or too cold, or didn't have adequate drainage... Maybe the seeds aren't even viable.

Good luck with them this time Chelle. I hope you get better results.

Karen

Thanks, Karen!

That was the first time I'd purposely attempted to germinate petunia seeds, so I'm not dismayed, just ready to change gears for next time.

Last year I "cleverly" made my indoor seed-starting mix faster-drainer by adding a lot of screened pine bark from a clean high-quality mulch I had high germination rates, zero damping off, and overwatering ceased to cause problems. Everything did much better ...

except for petunias.

In a 128-cell tray, almost NO petuinias sprouted. i think that was around 12 different varieties from trades, but near-ZERO germination had to be my fault.

I think the coarse surface of the mix let tiny petunia seeds fall deeply into the mix where they got no light. Possibly petunias LIKE a very damp surface and the coarse mix allowed the surface to drain too well, even though I used a dome or plastic film cover to maintain humidity, and sprayed the surface every few days.

In past years, I killed many seeds of other species but was always able to start petunias easily on top of soggy, peaty soiless mixes. This was in a cold room (55-60 F, maybe 65 F some days).

I did add a heat mat on top of a piece of drywall, but even if it rasied the soil temp by 15F, that would only bring it to 70-75 F or rarely 80. Also, since I shared one heat mat among several trays, only the center part of the tray got the full warmth, and some days no extra warmth at all.

I think it was the coarse, faster-draining surface of the mix that meant "no petunias" for me last year. This year I'm going to use the fine part of what I screened out to top-dress my petunia tray ... and maybe start two trays, one of them early enoguh that if it fails, I have time to start a second tray!

I had a bunch of bum seeds last year as well... it does happen.. but I found it best to put them down on top of the soil & use a strong hand spray bottle to squirt them and make good soil contact

Maybe I've just been lucky but my wintersown petunias have always been no-fail. I don't do all that messing with home made soils like Rick- just plain old ProMix or Fafard or whatever professional mix I get that year. Petunias are the one I just assume will always do well.


Laura Bush did too well. It reseeded with such a vengeance I had to stop growing it.



Karen

think I will put that one on my list then!!!

Hmm, somewhere I got the idea that Petunias liked warmth to germinate and were not good candidates for WS.

I have some notes (based on what source, i have no idea), that they like:
75-80 F + surface + light for germination ,
55-65 F for seedlings,
and "should" be sown indoors 10-12 weeks before average last frost.

If I sowed them outdoors where I live, it would be June (if ever) before they got soil temps of 75-80. I guess WS jugs in sunlight would warm up sooner, even in a very cloudy climate. But it seems a very uncontrolled way to keep seeds warm.

I'm a total WS newbie, and (other than last year) had great success with Petunias in trays indoors. If I do try to WS again, it will be with seeds that need stratification AND are hard to kill.

I'm gussing that people who have success with peaty commerical seedling mixes have learned how to avoid overwatering, and/or they're using deeper cells to start seeds in, than I do.

I've not tried WS petunias either, although I'm sure it would work if I started them later, with my annuals. When I start them indoors, I've had them blooming before they ever even got outside!! Gotta love anything that easy to grow.

that is the payoff for starting them inside.. have to wait for blooms when WS'ing.. I had a ton self seed last year and they catch up pretty quick.. but have to wait a few weeks for them .. unlike when starting them inside.. but the self seeded ones grew strong and fast

All this petunia talk is really exciting! I haven't opened a seed catalogue yet, but have a garden cub meeting tomorrow, so there should be some great new varieties covered at the meeting. Been really busy at work and there are quite a few new petunia varieties this year (Poprocks, Paparazzi etc). I hope to do an article later this month for ATP if I get caught up at work

Joanne please do!!


I so enjoyed all the information on the geranium forum.

hope you get to it.. can't wait to read it!!

Hi Joanne! I haven't run into you here in ages. Hope all is well.

Yes, some petunias when wintersown do take longer to bloom. I think that can be due to both cooler conditions and shorter days. Some series are more sensitive to these conditions. My pot of Silver Tidal Wave ones above took forever to bloom last year. In April we had rain almost every day of the month, (13.5" of rain in the month), clouds, cold, no sun. The year before, in a much warmer and sunnier spring, the tidal waves bloomed much sooner. This was some WSown Tidal Waves in June 2010, don't know the actual date



I've also WSown some Easy Waves. These are less photosensitve; they will bloom even with short days.
Note the last line in this blurb "Other Info : Easy Wave Petunias are less sensitive to daylength than Wave Petunias."
http://www.panamseed.com/serie...

Rick, my wintersown petunias usually tolerate light frost easily. And I'm pretty sure you're shooting yourself in the foot with those designer soils. Do yourself a favor and try a few jugs with regular old peat based potting mix. I think you'll get much better results. And stop overwatering! Many years I don't water my WSown stuff at all. If I do water, it's usually things that I'm late planting.

Karen

Karen, where do you get your Easy Wave petunia seeds from? Also, have you tried Tidal Wave petunias?

The pictures of pots that I posted above (both silver and rose) were tidal waves.

I don't remember where I got my easy waves. But Swallowtail carries them as pellets in small numbers. I really like the pellets for petunias, but I've used both pellets and raw seeds for petunias of various kinds.
http://www.swallowtailgardense...

Karen

the pelleted are so easy to sow