impatiens question

I have impatiens that have 2 sets of true leaves. They are growing in a 72 cell tray. I've noticed that some of them have white roots growing out of the bottom of their cells. Is this normal, or do they need to be transferred to bigger pots?

Hope you don't mind if I add a question. All of my outer cells of the tray have good germination, but the rows in the middle haven't germinated. No bottom heat and even light above and even moisture. Any suggestions of cause?

Joannabanana, Sorry about your middle seeds.
I am trying to think of a cause.
Only a few things I know of that's important on germination of impatiens seeds.

Temp between 70f-80f deggrees (soil temp not room temp) I check with a instant read thermometer :)

Surface sown, they need light for germination (Don't cover).

seed's kept very humid and/or moist until germination.

Not allowing the seeds to dry out.

Is it possible that the seed tray was on a uneven surface?
When i water the water goes right to the lowest point so if it is slanted one side will get to much water while the other gets not enough.

I know also that my impatiens seed's are started under a 48" shop light, it gets warmer in the middle then on the edge.
So my soil temp is measured in the middle. One day the middle read 85f !!! scary scary! but the edge was 80f big difference! Is it possible your seeds could of had the ideal temp. on the edge and not ideal conditions (As far as temp.) in the middle???

besides that I am really clueless what it could be? Sorry if this didn't help.

Pgt,
Sounds like you have great seedlings! Great job!
White roots are a wondeful sign of healthy seedlings. Brown roots say that they are struggling.
So you have a good problem on your hands, TIme to transplant :)
I just posted a thread on gardenweb.com about when I should transplant and yours sounds like they are more than ready.
Upgrade to a 3" diameter pot, they have a flat the 18 per pots per flat kind.
If you don't have that kind of room you could always pinch the leaves back while mantaining one set of true leaves.
But as long as they still seem to have room above and your roots are not crammed they may be okay.
I would say transplant if you can if you are in question at all :)

great job with those seedlings! Do you have any pics. of them?

Pgt, I am sorry I told you that I posted in Gardenweb It actually was posted in this site, My post was "how to successfully grow impatiens from seed" under this same forum. Tigerlily123 responded with some really helpful advice on transplanting and fert. you could check out what she said!

http://davesgarden.com/community/forums/t/958660/

Thanks for all the info guys! When I transfer them to bigger pots do I use seed starting mix or potting soil?

I would just transplant your seedlings into fresh potting mix, not seed starting mix.(Seed starter mix is great for starting seeds but It contains no fertilizer or compost so the plant would slowly starve if left in it the whole time until you plant out in the garden.) I would keep the starting seedling mix around the plant but just make a hole in the center of your pot with the soil potting mix and place the plant and with the mix around its roots in the middle. Then just pat the soil down just a little. The roots should then start growing into the new soil and gather all the nutrients it needs :)
Potting soil is the next step! :) Good luck!

NOTE: I forgot to tell you that the potting soil you may buy may contain slow release fertilizer, if it does try not to fertilize your impatiens while they are in your house. The potting soil itself contains enough nutrients to keep them going for awhile. If in doubt don't fert. more than what's neccessary. It is better to under do it, them overdue it.
Underdoing it may leave you with smaller less robust plants but overdoing it could kill them all! That would be badd! ha ha!
But as always do what you think needs done, go by what your gut tells you:)
Hope this isn't confusing...

Well, yesterday, I repotted them in seed starting mix before I saw your answer. Will they be okay if I fertilize them every few days, or should I pot them again using potting mix? Thanks, and this time I'll wait for your answer instead of jumping the gun.

I like to use compost tea on small seedlings... no chance of burning

pgt, hello again
I still think you will be alright even though its in just seed starting mix. Just make sure you fert. with 1/4 or 1/2 strength instead of using whole strength since that can hurt your plants. I am no expert so I would start out small on the fert. and maybe use a higher dose if they end up looking alright. If you were going to have your plants inside for a very long time it could be a problem without the fert. But with you fert. occasionally they should do well.
Oh another thing, only fert. by as often as the label says.
So if it says fert every two weeks by fert. every week you risk the burning or stunted growth from to much fert.
Less is more with fert! I think the seed starting mix may contain a few trace elments usable as food for your plants.
Obviously not enough to keep them thriving forever but it will help them make it to the garden. You could try somthing like
fish emulsion, or some other organic fert. But whatever you choose if your in doubt of how much to use go for less and examine your results before increasing the amount.

Oh ' one more thing it wouldn't hurt to look up fert. impatiens online, being new to growing impatiens myself you can never do to much research on the plants your growing. I have heard that some plants just won't do well with added fert. And others gotta have it to do anything. So even I could use some brushing up on researching best conditions for growing impatiens. If I find more information on it I will post it here. Best of luck!

Hi
I have a small greenhouse and I bring in some pots of bigger plants like hibiscus etc in the fall. I have a lot of shade so I plant impatiens all around in the summer. I now have impatians coming up in a lot of the pots that I brought in. It usually happens every spring. I pot them up and put them out in the summer. They are the toughest little plants I have ever seen. I just give them a little tug and sort of pull them out by the roots and put them in potting soil. I hardly ever lose any doing it that way. I live in zone five. Last spring I also had a lot of them come up volunteer last summer outside. Good luck on growing them, they are my favorites. Linda