Answer: Your lemon tree is probably 'Eureka', a common lemon tree in your region, with an open branch habit and few thorns. All citrus thrive in full sunshine and rich, moist, fast-draining soil. Citrus need moist soil, but never freestanding water. Since roots grow near the surface, mulch over the soil to help keep the roots moist and protected. Use a 2"-3" layer of organic mulch, or gravel.
All plants need an adjustment period after being transplanted. It's possible your tree was stressed prior to being planted in its new location and is responding by dropping leaves. Provide your tree with a deep soaking once a week (or twice in really hot weather). It may take a while, but it should perk up once the roots have become established.
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