You basically want to titrate their exposure to the sunlight and general outdoor conditions. I have a window awning with a table under it where I put my seedlings, after transplanting from my starter tray to a paper cup or small pot, for a week. The first day or two will get six hours, the next 8 and so on and so forth until they get nearly a full day's sunlight under that awning, which provides partial shade. After that week they can be put out until they fill your small container, usually 1 to 2 weeks, then transplant to their final destination.
I'm in the valley so I have different parameters but the hardening is universally beneficial. The Mass outdoor growers thread is your friend, I learned a bit by perusing it.
By capsids you mean fungus?