When I lived in Dallas the rule of thumb for caladiums (Neil Sperry was it Dawn?) was May 1. This prevented cold and moisture from rotting the bulbs. I've adapted this rule for Oklahoma, extending it by two weeks to May 15. Because caladiums and elephant ears get zapped in the fall at similar low temps, I've transferred that rule to elephant ears here.

I don't know about hostas, and can't help you with depth, as I plant mine "about that deep."

Seedmama, I think I'll always have Neil Sperry's voice in my head telling me what to do and how to do it, and that's a good thing! I do think May 1st was great advice for Dallas and the whole D-FW metro area perhaps even all the way up to the Red River. I still plant them May 1st (but, remember, I am so far south that I have Texas on three sides of me) if the soil temp is consistently 70 degrees and the 10-day forecast doesn't have any wicked cold weather in it.

For everyone in OK north of the Arbuckles, I would think May 15th would be a perfect date as long as the soil is warm and the forecast has warm nights in it.

If you want to get an early start, Momfryhover, plant them in one or two gallon pots in potting soil and place them someplace warm....a concrete patio or driveway slab would be ideal. You'll have to move them inside on cold nights though. Planting early doesn't get you much growth if the soil and nights are cold because the bulbs just sit there and sulk....or, if it is wet and cold, they rot.

For hostas, I don't grow them here since I discovered, after planting 30 of them here our first year, that they are "deer chow". When I planted them in Texas and here, I liked to plant the crown of the smaller ones 1/2" to 1" below the soil surface in black gumbo clay or a little deeper in really well-drained sandy loam. With the really large hostas, you can put the crown 1" to 2" below the soil surface in well-drained loamy soil, but a little more shallow than that in clay. (Really, clay ought to be well-amended for hostas and, in that case, you could plant them 1" to 2" below the soil surface.)

I think the whole issue of planting hostas deeply (or how deeply to do it) is more critical in colder climates where repeated winter freezing/thawing of the ground can result in frost heave, wherein plants are literally heaved upward out of the ground and then freeze to death.

If you plant the hosta crown just a bit below the soil surface and mulch well (mulch around the plant, but not on top of the crown), the plants should do just fine.

Dawn