We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Well, not really. It is planting time for tropical things like tomatoes and peppers up here in Yankeeland. Everybody likes to get an early jump on the season, but it's never worth the trouble. Annual plants do not get going until late May and June here.
On the other hand, from now on it's too late for planting shrubs and trees. Water them all you can for the first growing season, but transplantation stress and hot weather is tough. If they hold their own, next Spring they will grow fine on their own - if they like the spot you selected for them.
The great Ralph Snodsmith who had a gardening show on WQXR or somewhere for 100 years always said "Prepare a $50 hole for a $5 plant." With inflation, I'd say a $300 hole for a $30 plant.
Loosen up the roots of a potted plant, or chop them up a bit if the new plant is root-bound. After that, the hole is the thing. Double the diameter of the shrub or tree. A firm base, and fill with enhanced dirt (peat moss, planter soil, manure, whatever). I mix it all up for fill in a wheelbarrow to give the thing an easy start. Then soaker water plentifully the first year. Why? Because the plant doesn't have a sustainable root system yet, and to make it easier to send out new roots. Dry or compacted soil doesn't have the water space between soil particles in which to send new roots.
We planted a bunch of hollies this Spring. Actually, two batches. They are looking good thus far.
Your advice for planting a tree or shrub is exactly what Granddad (my wife's grandfather) advised. Worked every time in my experience.
I was pressed into servitude by my wife today to get her 'edibles' garden cleaned up and ready. We worked together but completely at her direction. My skills are in cutting, digging, plumbing (irrigation), and fastening.
She managed to get in some tomatoes and peppers (bell and ghost chilis). Not certain what else she has planned but in prior years she's planted cauliflower (don't tell AOC), brussel sprouts, peas, green beans, cabbage, and various squash and zucchini.
Here in Texas, you'd best leave the shrub and tree planting to the more temperate times. Rule of Thumb is Columbus Day to St Patrick's day for that big fancy hole. And soak it down once a week.
Unless, of course, you want "natural" trees. The birds will poop hackberry seeds along all your fence lines; you can cull out the ones you don't want, which is usually all of them. And you can always count on a well-rooted mesquite to sprout up in a crack in the sidewalk.
There is more. Most plants are root bound. Five year after planting it you could literally pull it out of the ground and put it back in the same pot you bought it in. The dirt and roots haven't changed shape or branched out (much). The traditional advice to cut the roots and remove as much of the small roots that are circling inside the pot will help maybe 5% or so. Best advice is buy a smaller newly planted/potted plant. One that is less than a year old. But you will be attracted to the larger ones that are looking good but it is likely they will never look any better no matter what you do. The smaller plant will need more care and take more time to fill out but the roots will grow better. Hint: You won't find these at Walmart or Home Depot.
On the Front Range of Colorado we can usually plant tomatoes and annuals mid-May. Transplanted tomato and basil seedlings around then and a week later got 3" of snow & 30°. Yesterday after a week in the 70s I put in annuals and 12 hours later a hail storm came through and shredded everything.