Blue Rug juniper, also known as Wiltonii juniper, is a sturdy, low-growing, thick carpet of silvery blue foliage that takes on a purple cast in winter. Although Blue Rug juniper won't grow more than 4 to 6 inches tall, a single plant can span a width of 8 to 10 feet. Blue Rug juniper is a drought-tolerant, nearly indestructible evergreen that will grow in almost any well-drained soil, making it a good choice for steep, difficult slopes. Although upright forms of juniper are difficult to propagate, low-growing juniper such as Blue Rug are easily propagated by taking a stem cutting in summer or winter.
Fill a celled planting container with a mixture of half coarse sand and half commercial potting mixture. Set the planting container in a tray of water and allow the potting mixture to draw up water until it's thoroughly damp. Remove the container from the water and set it aside until you're ready to plant the Blue Rug juniper cuttings.
Cut 5- to 6-inch tips from the stems of a healthy Blue Rug juniper using sharp pruners that have been wiped with rubbing alcohol to kill any bacteria. Make the cuts just below a needle or a leaf node, which is where a needle is about to emerge.
Strip the needles from the bottom third of the stems, leaving the upper needles intact. Use the tip of a sharp knife to scrape the outer bark from the bottom inch of the stems. Wounding the stems will stimulate rooting.
Dip the end of the cuttings in powdered rooting hormone and tap off the excess powder with your finger. Plant the cuttings in the celled planting container with the needled section above the potting mixture. Settle the potting mixture around the cuttings by misting lightly with a spray bottle.
Slide the planting container into a clear plastic bag. Install a piece of bent wire or some small stakes to keep the plastic from falling onto the cuttings.
Put the planting container in bright, indirect light in a room where the temperature will be maintained at about 65 to 70 degrees Fahrenheit.
Check the cuttings daily. If the potting mixture is dry to the touch, mist it lightly. Don't water excessively as too much moisture can rot the cuttings.
Move the Blue Rug juniper cuttings to individual 4-inch planting containers when the roots are about an inch long. To determine whether the cuttings are rooted and ready to transplant, dig one cutting carefully with a spoon. Check the progress of the cutting, then replant it. Rooting can take as little as three weeks or as long as three months.
Plant the Blue Rug juniper outdoors several months after the roots are well-established. A longer indoor period will result in a sturdier plant with a better chance of survival.