interesting question, because usually a larger pot is both wider AND deeper, to one degree or another. If it were a perennial, I'd say definitely go deeper, but as an annual that you might be putting into a decorative container, I'd say put it in whatever pot that will make it easier to transplant later. If it's going in a spot that will dry out quickly, maybe the deeper pot would be better, to promote the roots going deeper. ok, now I sound all undecided as well :)

Yeah, Rachel, it is a bit of a sticky wicket. I'll be treating them as perennials since I can overwinter them easily in the greenhouse. The problem is that tho they're small now, I will be putting them in a much larger pot (at least 18") when it finally gets warm enough to put them outside. I know I can't go directly to that size now & can't figure out the deeper or wider part. I have mum pots which are mostly wider & 1 gal pots which are mostly deeper!

I like the look of mum pots better, but 1gal pots will need less watering during the over-winter process (less surface area for evaporation). Do you minimally heat your GH for overwintering this type of plant, or just insulate it? (I always want to keep plants over the winter, but when I did the math, it is cheaper to repropagate most things than heat the GH at all until February.)

This whole topic leads to my similar question regarding vegetable seedling potting up. Seedlings have their first sets of true leaves, so it's getting time to pot them up into individual containers now. Do I plant them at the SAME depth? Or can I plant them a little deeper?

I know I can plant tomatoes deeper. They even like that treatment.

But what about brassicas (broc, cauli and brussels Sprouts? What about peppers? My pepppers are actually nice and bushy, but my brassicas are a little leggy...3 inches tall with 2 sets of leaves and I was thinking that if I can plant them deeper they will look a little less spindly. But I don't want to hurt them...

zengeos, I would think if anything other than the tomatoes was planted deeper, especially leggy stems, they would rot if planted any deeper. I've got some serrano peppers I started from seed & they were so spindly I had to prop them up with sticks! I just increased the amount of light & they rec'd & they took off great. And yes, Rachel, we do heat the greenhouse over winter. We try to keep it at 50 but sometimes the horrid weather drops it into the upper 30's overnight. You're right about the heating cost, we've had bills up to $750/mo but that does include the house. BTW, when the daturas are overwintered, they will be in the big 18" pots. I just need a decision for now, indoors and under lights.
Carol

If I ran up a $750 bill for heating (which included my GH) my husband would have me comitted for sure. Or at very least divorce me ;)

Wow, that's really amazing...

Considering I probably have $5000 worth of plants in there, he considers it a bargain! Still need to know how the daturas should be repotted. Have brugs but this is the first time with daturas. Do they have deep roots or a wide rooting system? Rec'd 1 seedpod from a friend & now have 28 double lavender swirls. Selling all but 2 for myself & need to keep potting those 2 up until they can fill 2 big, beautiful 18" pots. Any suggestions?
Carol