I have found impatiens to be a bit challenging for good germination. Last year I did manage to get one variety to germinate quite well. I just got a seed order in and thought I would sow a tray of impatiens. The package from Stokes Seeds had instructions that I never heard of before. Apparently some impatiens will not germinate with a lot of red spectrum light (natural or artificial) so they suggest covering the tray with blue plastic. How on earth would someone figure that out? I'm going to try it and see what happens.
I have always had very good luck with all the impatients I have grow except one variety...summer romance from burpees. Year after year I get only 10-20% germination. Compare that to 60-70% germination I get from new guineas.
I gave up growing New Guinea Impatiens here in Houston. They droop when its hot and if I water them or mulch, they rot. I'll try them again when I have more experience under my belt. Good luck to you all.
Joanna, did you happen to try some without the blue plastic to see if it truly was the plastic that did the job, or your germination skills in general? Also, what variety and series were the impatiens with those instructions?
I have some impatiens seed coming and I may try a couple of different treatments to see if I get any differences.
1. Standard practices germinating under cool white florescent lights. 2. Standard practices under cool white bulbs with blue plastic. 3. Germination using sunlight from windows. 4. Germination in sunlight with blue plastic.
My guess is that I will find no differences with the treatments under cool white florescent as these bulbs put out predominately light in the blue spectrum with much less in the reds. I would expect to find differences in the two treatments with sunlight as that has a much larger amount of light in the red spectrum.
If others are interested in experimenting, please try some of these comparisons and report back here, it would be interesting to see the results. I'll report my findings under this thread, but I am still waiting for my seed.
This year, I've only started the Envoy series so far. I have a few seed orders due to arrive any day and there are impatiens in those orders. In past years, I have had entire packages not germinate, with others in the very next tray that did.
I started about 200 impatiens seeds last week and had the first one germinate about 4 days later. About 60 out of 70 cells now have seedlings and/or germination. Had them on a heating pad with a dome on top but not under lights, just whatever ambient room light they got (not enough room under the lights for them right now). I was a little worried they might not germinate b/c they are in cell packs and so I thought the dirt might not warm all the way to the top where the seeds were, but they seem to have done ok. Hopefully I manage to keep them alive! They are the Fanciful type double impatiens, so I'm excited to see how they turn out. They are such thin, fragile little seedlings!
Hi all, I found this description of filters and light here:
This is a teaching plan dealing with light. I don't pretend to understand the physics of light transmission, but this explains it fairly well. I copied the relevant portion here, so you don't have to go to the link unless you want to play with different light filters and see the effects.
A filter is a substance or device that
prevents certain things from passing
through it while allowing certain other
things to pass. Color filters allow only
certain colors of light to pass through them
by absorbing all the rest. When white light
shines on a red filter, for example, the
orange, yellow, green, blue, and violet
components of the light are absorbed by the
filter, allowing only the red component of
the light to pass through to the other side of
A pure filter allows only a single color of
light to pass through it. Like pigments,
however, most filters are not pure—they
allow more than one color through. For
example, most yellow filters also allow
some red, orange, and green light to pass
through them, but our eyes see a mixture of
yellow, red, and green light as simply
yellow. Likewise, a blue filter allows some
violet and green as well as blue light to
pass, but our eyes perceive the mixture as
Overlapping different color filters (placing
one on top or in front of another) is a lot like
mixing different food colorings in that new
colors are formed by the process of
subtractive color mixing. Each color filter
that is added subtracts certain colors from
the colors of light that strike it. For example,
if the blue and yellow filters mentioned
above were overlapped, the yellow filter
would absorb the blue and violet light that
passed through the blue filter, allowing only
the green through.
Under cool white shop lights I have always had almost 100% germination, with no blue plastic. I use 10 x 20 trays, and re-use six-packs with Jiffy Mix as growing medium. Sterilizing soil or not hasn't seemed to make much difference. I lightly firm the soil and gently press the seed (one per cell) into it, to be sure of good soil contact. I bottom-water with warm water, until the cells have soaked up as much moisture as they can hold, and drain off excess. Flats are then covered with clear plastic domes and placed under the lights, with no bottom heat. Even fluorescent lights provide warmer-than-room temp, especially when they're only an inch or so above the domes, which retain that mild radiant heat without "cooking" the seeds. These were with the Accent variety, and always with a mix.
(By the way, I line leaky used flats from years of yore with plastic - polyethylene/visqueen (sp?) - so as not to have to replace these very often, until they completely fall apart.)
This year I used a blue-looking but still "aquarium" type of light tube, and had 90% germination on the Tempo Cancun mix. These were with Stokes seeds - I read the same packet! (I wish Stokes would say *which* colors are likely to be limited.) But I sometimes think those recommendations are very general, and that the response you get with various cultivars will vary. It's possible that the Tempo aren't quite as vigorous as Accent. There are three different colors in this mix, and if my light situation was going to wipe out or limit one of them, my germination rate should have been less, I think. I'll watch what colors I get, when they bloom, and see if I only get half as many of one color than the others.
If I grow impatiens next year, I'll go back to shop lights at least for germination. Nothing fancier seems to be necessary.
I believe that maintaining the humidity levels and a fairly constant temperature is what helps the most in my seed-germination rates, with seeds of every type. The domes help a LOT. Germination rates of things I plant by popping a seed onto soil and sticking it in a window (Brrr! especially at night) are spotty at best, and usually unsuccessful. So are most other shortcuts and compromises, including using any coarser growing medium than Jiffy Mix. If I really care whether something grows or not, I have to do it "right", with all the elements above. Your mileage may vary, of course, but that's my 2˘. Hope it helps!
If anyone needs blue plastic...I have a lot of recycle bags...just know that they are not completely clear. (Well most of them are clear, but thick enough to hold garbage. I will select for the clearest ones.
After reading much material and contemplating various others comments, I think that the recommendations from Stokes probably pertains more to those germinating seeds in greenhouses using sunlight for their primary light source. Using any type of artificial light (with the exception of HPS) is much less likely to provide enough red light to inhibit germination. I think that is why so many have not had problems with germination under florescent lights. Anyway, these are my thoughts only, please everyone keep experimenting and report your results here.
As for the experiments I mentioned earlier in February, I have now been waiting for a whole month for my seeds to arrive from Park Seeds (reviews have been added) with no indication of when they might be shipped. If and when I get them, I still plan on conducting the experiments mentioned earlier in this thread.
I am shocked about your Park Seeds order. Last year I had some trouble with them. Right now, they do not have the time to pay much attention to emails, so after I made the phone call, everything got straightened out in a hurry. They told me about emails at the beginning of the season...they are just not at that computer, I suppose...Now I won't buy any plants from them, but seeds, yes. Also they are less expensive than Burpee, and they have some seeds that others do not.
Good luck, and let us know how it turned out, after the phone call...they might have less help as well, and possibly new people that might not quite yet be "on the ball", or well-trained...though I imagine they would not be hiring new people after they laid off the old ones...
I have had good luck with pelleted seeds. I start them in Jiffy cubes on the heat mat. They set buds still in the Jiffys before I can transplant them. I like to put some in pots on my balcony for the Summer. Here's an unusual seedling I had last year.
OK, I have a question...is it too late to start impatiens now? I had a lot of other seeds to sow and want to sow these now. The impatiens (store-bought plants) do well all summer, but I have not sown the seeds before.
So sad, Parks was the premier seedsman for so long...Impatiens seeds are everywhere in the racks. Wally World, the big box home stores. Look at your local "dollar" type stores. I was there tonight, they had 100 pelleted seeds for $1.00. I planted them last year, a glorious mixture! I left them in the Jiffy cubes, they even set buds before I could plant them.
Hi all, I finally got my seed from Parks after 7 weeks. Impatiens Accent White. Parks said to surface sow (need light) to germ, but Stokes recommended 2 days of darkness after surface sowing for the "Accent" series. I didn't want to waste any time running experiments as it is so late, so I followed Stokes rec. I surface sowed and placed in dark for 2 days then moved to light (cool white florescent) all at ~68 degrees. After two days in dark, seeds had swollen, by three days I could see white roots starting to emerge and by 4 days >80% germination.
Conclusion: None, I wasn't able to make any comparison with light, dark or colored filter, so all I can say is that Impatiens Accent White will germinate when kept in dark for two days followed by light.
As I mentioned before, I have a feeling that use of blue plastic/filter is more applicable when germinating these seeds in greenhouse with a majority of the light coming from sunlight or lights with red/warm light spectrum.