Aubrieta

Growing Aubrieta from seed is a rewarding project for gardeners looking to add a vibrant carpet of purple, pink, or blue to their landscape. Also known as False Rock Cress, this hardy perennial thrives in cooler climates and is a classic choice for alpine-style plantings.
Seed Sowing Guide

You should start Aubrieta seeds indoors 6 to 8 weeks before the last expected frost date in your area.[1][2] Use a sterile, well-draining seed starting mix. It is crucial to note that these seeds require light to germinate.[1][2][3] Do not bury them deep in the soil. Instead, press the seeds firmly onto the surface of the moist potting mix. If you must cover them to anchor the seeds, use a very thin layer of fine vermiculite that still allows light to filter through.
Tips for High Germination Rates

To maximize your success rate, control the temperature and humidity carefully. Aubrieta prefers cooler temperatures for germination compared to many annual flowers. Maintain a temperature around 65°F to 68°F (18°C to 20°C). Temperatures that are too high can inhibit sprouting.

Cover your seed trays with a clear plastic dome or a plastic bag to create a mini-greenhouse effect, which retains the necessary humidity. However, you must ensure the soil remains moist but not waterlogged to prevent rot. Once the seedlings appear, usually within 14 to 21 days, remove the plastic cover immediately to increase air circulation and move the tray to a bright location, such as a south-facing window or under grow lights, to prevent the plants from becoming leggy.
Landscape Usage Scenarios

Aubrieta is exceptionally versatile in garden design. Its most iconic use is in rock gardens, where it can be planted in crevices between stones. As it grows, it forms a mat that helps suppress weeds and softens the hard edges of the rocks.

Another popular application is planting it along retaining walls. The plant has a cascading habit, meaning it will spill over the edge of the wall, creating a "living waterfall" of color in the spring. It also serves as an excellent ground cover for sunny slopes where grass is difficult to mow, or as an edging plant along concrete walkways, where it softens the transition between the path and the garden bed.