CAUTION!!!
Never put newly bought plants with your seedling you started at home. Keep them in a separate spot away from the healthy ones and treat them with neem oil, or your choice of insecticide or fungicide. After a day or so, when you are sure the newly bought plants are safe from any disease or pests, then introduce them to the rest of your plants.
I made the mistake once and purchased several store bought herbs and veggies and immediately put them with my seedlings I started at home. Some of them had pests and fungus on them that I didn’t see. Well, they spread to my seedlings and it sucked! All that time growing and I lost a few.
What pre-cautions do you take before introducing new plants?