Question about aphids

Question about aphids

Hello. I'm new to this community. I'm a home gardener living in Tennessee, and I'm looking for some advice regarding aphids. My three tomato plants are infested with them right now, but none of my other plants seem to be affected (pepper, eggplant, cucumber, beans, peas, zucchini, and strawberry). I tried sevin dust, to no avail. *I've heard that a strong jet of water will help, but I'm worried about damaging the leaves as the plants are fairly young (plus, I'm assuming this will not actually solve the problem). *There are websites that mention using soap and water; does this actually work? *Any other ideas? I'm tempted to buy one of those "garden-safe" insect sprays that supposedly retains the "beneficial" insects, but I'm willing to try anything.
Bottle brush tree

Bottle brush tree

Mystery Ground Cover (weed?)

Mystery Ground Cover (weed?)

Zucchini and Ginger

Zucchini and Ginger

Asakura – a Japanese sasanqua with large flat semi-double white flowers and upright growing habit

Asakura – a Japanese sasanqua with large flat semi-double white flowers and upright growing habit

Floriade

Floriade

Crocuses!

Crocuses!