Zinnias are native to Mexico. They have been grown since 1520 by the Aztecs. Zinnias were brought to Europe in 1753. They were named after Johann Gottfried Zinn, a professor of botany. Start from seeds in the garden. Zinnias love hot weather. Plant seeds in mid to late May. Plant the dwarf kinds of zinnias one foot apart. The tall-growing kinds should be planted two feet apart. Zinnias are easy to grow. Pinch off the dying flowers to keep the plants flowering. Zinnias look great in flower arrangements. Water when dry; early in the day so their leaves will dry off before nightfall.