I only have experience with trilliums.... They grow well around here. There were a few already here when we bought this property in 1999 but we're added to them since. What has worked for us is to plant them dormant in mid summer, plant them in areas with lots of leaf litter - under trees, and never water or disturb them while they are dormant! There are lots of squirrels here and, as far as I can tell, they've never bothered them. The white trilliums are more vigorous for us than red ones - white ones are the provincial flower of Ontario so that might be a sign that they are particularly suited here. They are now spreading by both offsets and seedlings. Some pictures....:

Cole in the nearby 'trillium wood' that is my reference for what I'd like to have here!

White trilliums near the shed in our garden:

A closer view from 2015 where you can see seedlings getting big enough to start to bloom:

(Note the plentiful oak leaves in those pictures! The trilliums seem to like those conditions....)

Red trilliums don't seem as happy here and are spreading much slower:

On the issue of squirrels and tulips.... Here the squirrels seem inclined to ADD tulips to our garden! Several years after we started gardening here, a clump of orange tulips appeared under the oak tree in the back yard. We didn't plant them and the tulips looked suspiciously like ones in a neighbour's yard down the street! :-) So we assume the squirrels planted them..... Aside from deadheading the tulips once the flowers fade, I do nothing to them - they keep returning and the clump gets bigger as the years pass. The oldest picture I can find on this computer is 2010 but I think they first appeared before that.

2010:

2015 (apologies for the poor picture quality!)

Some salmony-pink tulips appeared in the front garden 2-3 years ago that I was sure we didn't plant and, looking around, I saw the same ones in a garden across the street! So squirrels might dig up the occasional bulb, but they are probably gifting it to a neighbour :-)

I can only hope I can get that look in time! It's lovely. A nearby woods is known for its white trilliums. They are not common here where most land is former farmland, but a few intact woodlands have them.

The red trilliums from my Mom she bought originally from a native plant nursery. So it could be my soil is not optimal for them either. The nearby woods I mentioned with the white trilliums does not seem to have red ones. A preserve I go to near a friend’s, 30 miles away, south and west, has abundant red ones but only a few whites near a pond. That area would potentially be flooded at some times.

I have been raking ash leaves into the bed where I am trying to grow them for at least 15 years. The soil is getting softer over time as the humus builds up.

Not watering while dormant could be a problem. I have hostas – lots of them - ferns, ligularia, goatsbeard, cimicifuga, and other similar plants in the same bed. I’d have to find a place without any other plants to plant the trilliums. I don’t water a lot, only if it’s desperately dry.

The nursery that I bought them from is in Tennessee. They would go dormant there much earlier than here. Probably why they were available to buy in late April.

I find tulip bulbs shredded, so most are being eaten (sloppily) . I plant a lot, so I could spare a "gift" to a neighbor. Though since I have no gardening neighbors, if a stray one were to show up in their lawn, their landscapers would pull it out, most likely.

I hope that the nursery you ordered from has been propagating them in the nursery and not digging them in the wild. Unfortunately, it's a common practice with many less than ethical nurseries.

Woody, your trilliums spread! Beautiful! I should think about moving my poor clump. I have had them for at least 20 years, and they have not spread at all. But maybe the north side of a fence in an area that gets run off from the concrete ‘patio’ next door is not the ideal spot ;-). Actually, they did better before a former neighbour plonked that concrete over half his back yard. All of a sudden certain plants disappeared, and I have replaced them with plants that don’t mind wet feet too much. The trilliums survived and stayed. Maybe they will do better under the apple tree. I have some red trilliums there, and they increased a little bit over time. Here is my little patch last year:

gdinie - yours might indeed prefer to be under the apple tree but you wouldn’t want to lose them after all this time - so be careful...! Maybe after they go dormant after flowering try to carefully dig up and move half the clump and leave the rest so you have a few left if the others don’t like the move. In my pictures above you can see the white ones with a lot of seedlings growing along a fallen tree.... That tree is a dead apple tree! The trilliums seem to particularly like that spot so if you have any dead apple tree limbs or trunks, maybe put them beside where you move the trilliums to...?

The white trilliums seem pretty tough. A few years ago the water treatment plant where the ‘trillium wood’ grows was expanding. All the top soil where the new building structures were going to go was scraped off by a bulldozer and left in large piles. There were lots of trilliums in the area cleared so we expected they’d all be lost! After the construction, the soil was spread around by ‘dozer again. The next spring, the area was covered in trilliums again! It undoubtedly helped that most of the soil moving was done at a time when the trilliums were dormant. I suspect that trilliums often don’t do well in gardens because there are ‘loved to death’ rather than just given reasonably suitable conditions and left to their own devices!

gdinie - you should drop by in early May when the trilliums bloom (usually around May 10) and check out the ‘trillium wood’ - it’s just a few minutes away and some of it is visible from the road if you know to look for it as you pass by.... It’s a pretty amazing sight! Mind you, it’s also where the coyotes live :-) It’s also very popular with ‘birders’ as the pools of water at the plant provide warmth and insects/larvae for birds, especially early migrants in spring and late ones in fall.

A blog post on how to divide trillium: https://awaytogarden.com/2-becomes-200-how-to-divide-trillium/