I should have clarified. I meant when you move the plant from the dark house, put it in the shade where it does get a little sun, and gradually move it into the full sun. If you do go directly from the house into the full sun, it will probably get sunburned. Which might not kill the plant, but may make it look ugly or lose leaves until new ones start to grow.
Plants grown in pots do need different requirements from those grown in the ground. You have to take into account the roots get a lot hotter in a pot than in the ground. For example, when we moved to TN I took my Calla Lilies and planted them in pots. The soil is terrible here, basically rock. It doesn't absorb the sun, it reflects it. Those poor little Callas had pots that were too hot to touch, and surprise, surprise, they didn't grow well.
And if you do spray for bugs with the horticultural oil, you want to do it in the late afternoon so that the oil can dry before the sun hits it. It'll say that on the container. (that is, if the tree is outside) I do spray mine, they always seem to get buggy the last month or two before they can go outside. It might also like a little liquid iron, which you buy in a brown bottle and dilute, you can spray on or put it on the soil. Citrus are notorious for becoming iron deficient.
All that sounds like a lot of work, but it's not, really. And your plant will be very happy outdoors this summer.
