In reverse chronological order (newest on top), this is an ongoing list of online stores and nurseries I've used to purchase plants by mail from their website. I'll include a very brief account and links to the individual unboxing post when applicable.
Sooner Plant Farm
I ordered a small tree from Sooner Plant Farm's website. I was so frustrated after driving around town looking for one locally, so I'm glad I found exactly what I was looking for online. Coincidentally, they have rave reviews and awards for their shipping service. I was very impressed when the huge box arrived on my doorstep. It shipped all the way from Oklahoma and the soil was still damp when I took it out of the box. I love this little tree and it's doing just fine! Shipping was about the same as the plant itself, but what can you do - they were sold out at local nurseries and it came straight to my door.
High Country Gardens
I ordered quite a few plants from High Country Gardens all in one batch. I actually ordered in two shipments and they were nice enough to combine them to save me money on shipping. Some of the plants arrived smaller than I expected, but overall healthy. I did lose a Globe Daisy, but High Country Gardens reimbursed me for that one. After 4 days in a box shipping from Colorado, losing 1 plant out of 9 isn't bad at all, and they didn't give me any hassle for the dead one. I was worried they'd want me to mail back the dried up husk or something to prove it.
I ordered three Itea virginica 'Sprich' Little Henry® online from Greenwood Nursery. They shipped in recycled shredded paper and arrived in good condition. They only had to travel from Tennessee to get here, which didn't take long. The leaves looked bright and fresh when I opened the box, and they are working to adapt to full sun in my back yard. One is putting on quite a bit of growth after about a month and a half.
Hirt's Gardens (via Amazon)
second online live plant order came through Amazon but was sold and
shipped by Hirt's Gardens. I ordered a small bamboo plant in the dead of winter and it arrived frozen solid in spite of the hand warmer they
included in the package. I thawed it out and the bamboo lived, and is
not thriving in my side yard.
My very first online live plant order was from 1800flowers.com, I got Chris a bonsai ficus for Valentine's Day. I chose this place even though I found the same tree for cheaper on Amazon because they are usually really good at making sure it arrives ON the actual day.