Ensure there is adequate soil drainage. Sagina subulata Aurea is susceptible to crown rot if it sits in water.
Water to keep the soil moist at all times. Although Sagina subulata is somewhat drought tolerant, in areas with warm weather, not enough water causes browning.
Grow Sagina subulata Aurea in an area where it receives morning sun and shade during the warmest part of the day -- if you live in a region with hot weather. Too much hot sun turns the plant brown.
Fertilize the Sagina subulata in spring and summer. Irish moss thrives in soil with a slightly acidic pH, so use a fertilizer listed for acid-loving plants, and apply it according to label instructions. Water as you normally do after application.