A thriving green yarrow charms autumn days when all the summer blooms have faded

During the shorter mid-fall days, when the vegetables, annuals, and even some perennials are finished for the year, you can really appreciate a thriving green yarrow, Achillea millefolium,m whose lovely feathery foliage appears to surpass even the most beautiful fern.

This aromatic Eurasian perennial herb thrives in poor sandy soil in full sun or part shade and survives hot, dry weather nicely. The plant is supposed to enhance the flavor and vigor of herbs grown nearby, and a tiny portion of yarrow leaf is a compost activator.

Every spring, the one yarrow that grew in a thicket of long-established perennials in our south perennial border produced two deep-pink flower heads that we cut and brought indoors. But the plant, at least 10 years old, was practically odorless.

When we crushed its tender leaves, no aroma was released, the pleasant yarrow aroma of wild northern yarrow. So we bought a package of yarrow seed, which is very fine, and prepared a bed at the south edge of the vegetable garden, close to one melissa and two rosemary plants.

About this time we cleared a spot for our pink yarrow to give it more light and more space. We dug out a chrysanthemum, filled the hole with garden loam, and transplanted the established yarrow. Then we spaded the 1-by-3-foot planting bed, raked it level, and scattered the tiny yarrow seeds over it.

Before we laid maple branches on top to protect the sowing, we pressed the seed into the soft earth with a wide firebrick.

Many a sowing of very fine seeds, such as meadowsweet, does not produce one plant, but the yarrow seeds became seedlings within three weeks. At the time of their first weeding they needed very little thinning. They blossomed in mid- summer, two flower heads that were very pale pink, the rest white.

As for the aromatic foliage, the fragrance was barely noticeable. The soft, green, fine-cut leaves are our yarrow's greatest asset.

In ancient times yarrow was called soldier's herb and woundwort.

Yarrow grows wild in Europe and is almost a weed in some Northeastern regions of the United States. One yarrow is called achillea and is listed among perennials in some seed catalogs.

Our yarrow grows about two feet. There is a dwarf variety that is a fine ground cover and can be used in place of grass, especially on very poor, sun-baked earth.