Needs Dark to Germinate???

Perrysburg, OH(Zone 5a)

Off the top of your heads, what annual seeds need dark to germinate? I've got alot started and a few aren't doing anything yet, I thought usually the packets specify if they need dark to germinate, but I was just curious. The seeds I'm questioning in particular are annual poppies, purple basil, nicotiana, cobacea, and cleome.
Thanks,
Becky

Newnan, GA(Zone 8a)

cobacea needs to be soaked and then planted on its side.

Hillsboro, OH(Zone 6a)

Hi Becky,
I don't know if you have it or not, but this germination database is pretty good. http://www.backyardgardener.com/tm.html

Westbrook, ME(Zone 5a)

I don't think any of those require dark. The ones that I always think of are salpiglossis and schizanthus. They're tough because the seeds are so tiny they need to be surface sown and then covered with something to keep them in the dark. I usually put a folded newspaper over the flat.

Perrysburg, OH(Zone 5a)

Thanks everyone, I didn't know about the cobacea, and the I haven't read the germination data base at all!! IT'S VERY COOL!!!
Thanks alot again,
Becky

Seward, AK(Zone 3b)

PoppySue: I surface sowed my salpiglossis under lights and they came up. I'll have to check the package instructions again.

Newnan, GA(Zone 8a)

I winter sowed my salpiglossis, and they came up. But sometimes just covering them with soil will be enough dark, right? or not?

Westbrook, ME(Zone 5a)

tiG - I bet they'll be alright. My book says they need dark - but Weez said hers were in light. I remember having trouble getting one or the other to germinate without the dark. It could have been schizanthus tho. Salpiglossis is really pretty... You'll love them!

Seward, AK(Zone 3b)

I transplanted my salpiglossis container today, and I had a good germination rate. They were surface sown with sand, then pressed in the surface with another container bottom, then put under lights, so I guess they don't mind. I usually just treat them like nicotiana or petunias. There is a chocolate variety that is dark chocolate brown and quite a stunner. I collected seed, but will have to wait to see if they come back true. If so, I'll have more next fall.

Castelnau RB Pyrenée, France(Zone 8a)

One source i found says nemesia needs dark, but it self seeded one year in my garden. Any thoughts on this one anybody??

Seward, AK(Zone 3b)

I don't recall covering mine, and I start all my seeds under lights, Philomel. Of course, I they are a flat little fuzzy seed, and I think I cover them lightly with starter mix...so, as tiG mentioned, is that excluding light? I've always assumed I had to cover them with something that would shut out all light, but I could be wrong.

It seems to me that verbena and cynoglossum both need to have light excluded during germination.

Newnan, GA(Zone 8a)

got a new verbena from Pinetree and winter sowed them, seems most came right up. If I put something over seeds or put them in the dark, I forget:) And one more question, is there a bottom to a seed box???????????????????

Seward, AK(Zone 3b)

You know, tiG, I'm beginning to wonder if any of these seeds need darkness to germinate. So far, we've all come up about zero, except the schizanthus and cynoglossum. Anybody got any info on those? I think this is a rather interesting subject, because, as you said, covering those containers requires a good memory, which I sure don't have. If they germinate and you don't get the covering off them, they are sad and leggy. If they are covered in starter mix, they hit the light as soon as they immerge...sounds better to me. Are there any seeds tht are supposed to be surface sown but require darkness to germinate?

I use small starter containers, 3x5, or 5x7, to broadcast small seeds. Once I've added the starter mix, in order to level it out and compress it slightly, I just take another container of the same type and press it lightly down in the first.(The bottom of the empty container is sitting on top of the starter mix.) I mist the compressed starter mix, then plant...is that what you wanted to know?

Westbrook, ME(Zone 5a)

Ok Weez - you made me get out my Dr.Deno book - LOL!!! This is just what he found from his research. Nothin's written in stone. He says ...

Salpiglosis - germinated at 70º (100% in the 2nd week) and at 40º (100% in 7-9 weeks) - Light had no effect. [so I was wrong]

Schizanthus hookeri - germinated at 70º Dark (57% in 2-14 days). At 70º light (0%). The seeds in light were then shifted to dark - whereupon 27% germinated on the 8th day - showing light inhibits the germination. However - the commercial 'Disco' hybrids did not show this behavior.

Cynoglossum [this is an odd one] - Seeds sown at 70º light germ. 100% in 2-3 days. Seeds sown in 70º dark germ 0%. Seeds sown @ 40º dark germ. 70% percent in the 4th week.

tiG - you're hooked! You will never EVER see the bottom of your seed box again!!

Seward, AK(Zone 3b)

Oooooh! Now I get it, tiG...I didn't catch what a "seed box" is...As Poppysue said, you'll never see the bottom again. Although, this year I saw the bottom of mine when I had to transfer all the bags of seed to a BIGGER tote.

Yes,Poppysue, that is a strange entry for cynoglossum. I haven't been having a very good germination rate with them, so I'll take a look at the package instructions again. Zero germination in darkness? Your Dr. Deno book sounds like a real gem!

Seward, AK(Zone 3b)

Well, I'm back, having looked at the two cynoglossum seed packets I have, one says "sow seed in a sunny window" and the other says "firming soil over seed, seed needs darkness to germinate".

So that brings me back to this question: If seeds are sown with a covering of soil or medium, is that considered "excluding light"?

Westbrook, ME(Zone 5a)

I don't think soil always excludes light. I spose it depends how deeply they're sown... anything deeper than an inch would exclude it for sure. If you just sprinkle a bit over the surface of the seeds - I'd bet enough light can get through for germination.

But if you were to plant them outdoors in 40º weather they would germinate in dark - according to his test. Do they re-seed for you? They do here. I haven't had to plant any in years. I always have some come up somewhere in the garden. Those little sticky seeds get me every fall when cleaning up. I've ruined many sweaters!

Seward, AK(Zone 3b)

Nope, I think our season is too short. I really love the deep blue flowers, and they bloom about the time the calendula are up and running, so it's a lovely combo. I've had lousy luck germinating them the last year or so. Guess it's time to re-evaluate.

Ottawa, ON(Zone 5a)

I found this 2002 (!) thread while searching for something else, and read through it because it discusses two of my favourite annuals, schizanthus and salpiglossis. I grow these every year (for 20+ years now) because I rarely see them in nurseries.

I can report that based on my experience they do NOT need darkness for germination. I sprinkle the tiny seed sparingly over damp ProMix in a 4" pot, press down lightly, bottom-water, and put them on top of the fridge. In 3-4 days they start to sprout and they go under lights. At 2 sets of true leaves I prick them out into cell-packs.

This year I've got about 5 dozen of each growing on for spring planting. Photo: salpiglossis lasts 10-14 days as a great cut flower

Thumbnail by andycdn
Seward, AK(Zone 3b)

Aren't the salpiglossis just amazing looking flowers! The colors remind me of old tapestries. Have you tried Chocolate Royale? It is a deep velvety brown.

Ottawa, ON(Zone 5a)

Yes, they are amazing. I usually buy the Bolero mix for salpiglossis, and there hasn't been a Chocolate Royale yet. But last year I had one of the dark blue ones, and saved some seed from it. Who knows what I'll get this year! It did germinate easily. It's certainly a flower worth growing -- better appreciated close-up. Not a subject for mass planting.

Shenandoah Valley, VA(Zone 6b)

Okay, it's an herb, but an annual one: basil needs dark. At least, the only basil I get to germination has been covered w/ dark paper.

Painesville, OH(Zone 5b)

The Genovese basil seeds I started were under lights (barely covered with vermiculite) and germinated quickly. Tamara

Shenandoah Valley, VA(Zone 6b)

Really? Geez. I did a test under lights and everything. Someone's playing with my mind...

Painesville, OH(Zone 5b)

Isn't it weird? I have heard of other this happening with other types of seed. Mother Nature has a sense of humor! Tamara

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