Shopping for a water softener: 1  Salt-based units need to have the salt replenished on a regular basis, usually at a cost of anywhere from $2-$15 a month depending on the cost of the salt ($3-$8 per 40-pound bag) and the amount of salt used by your system.
Milkweed is the common name for perennial, herbaceous plants of genus Asclepias, family Asclepiadaceae (from Greek physician Asclepius). One hundred species occur worldwide; 13 are native to Canada.
Planting Zones for Milkweed Plants. Milkweed plants grow as wildflowers in fields and along roadsides in Eastern North America. The common type typically grows in zones 3-9. Sun and Soil Requirements. Common milkweed plants grow best in full sun and in a well-drained soil, but, as tough as they are, they tend to tolerate clay soil, as well.