One of the main reasons we buy seedlings is because we want to get a jump start on planting to save time. However, it's important to learn how to choose good seedlings when we are shopping at a nursery or gardening center. It's important Not to shop with our feelings and really take a good look at the seedlings with an careful eye. By that I mean, don't grab the tallest plant thinking that it's the healthiest because that's not true. Bigger does not mean better in this case because taller plants can suffer the most during a transplant creating a transfer shock.
A nursery can be overwhelming with all the different and beautiful flowers and plants to choose from while the nursery makes it look so easy to care for...that's why it's better to shop from a place where they actually know about the plant you are buying!
Do Ask Questions
Ask if the plant have been chemically treated.
Ask if the plant is a Hybrid or Heirloom. Ask ask , and ask.
Read the Label
Find out which season the plant grows best in. Find out the plant's characteristics and qualities.Google about the plant while you're on location to educate yourself.
Carefully Check Out the Roots
Roots should be white. If the roots are brown, it's pretty much dead, the survival rate is slim to none. Brown roots are possibly from lack of oxygen, over watering, over fertilizing, etc. Check and see if the roots are protruding from the pot. I believe it's called a rootbound plant which will need to be repotted.
Check the Foliage
Green leafy plants are best. Stay away from pale yellow foliage because it's lacking nitrogen. New shoots and flower buds are good. Wilted, spotty, or curled foliage is not good. No leggy stems.
No Freeloaders (Bugs)
Always check to make sure pests such as: scale, aphids, white flies, etc are not nesting on the plants stems or foliage.
Lastly, check the soil and make sure it's been watered and looks healthy. If you're unsure...walk away. Leave it behind.
Remember good seedlings grows good plants!