Ageratum
These medium and low growing annuals are natives of Mexico. They have ovate leaves, 2 inches long and small clusters of fluffy, lavender-blue, white or pink flowers that are from 2 to 4 inches across. They are used for edging or carpeting flowerbeds, for window and porch boxes and in borders.
POTTING
The best compost to use is half loam and half leaf mold, with sand added. If dead flowers are removed, the flowering season will last longer.
PROPAGATION
Seeds are sown in late winter or spring in flower pans or flats that are filled with light, sandy compost in a warm greenhouse with a temperature of 70-75 degrees. They should be planted eight to ten weeks before they are wanted for planting outside. Sprinkle the seeds thinly on the surface and lightly cover them with soil. The seeds need light to sprout; do not cover them. When they're an inch or so high, prick them out and plant, 2 inches apart, in flats containing the soil mixture described above in potting. In ten days pinch the tips off to induce branching. If they are to be planted outdoors they should be hardened off a couple of weeks beforehand by placing them in a cold frame. They may also be potted separately in 3-inch pots instead of flats. They should be placed 6 to 9 inches apart in the flowerbeds. They can also be grown from seeds planted directly outside in the spring, although they won't bloom as early as those started inside.