Scleranthus uniflorus for "Grass" in Miniature Gardens:
Scleranthus uniflorus commonly named 'Knawel Cushion' is an evergreen, tuft forming groundcover plant native to New Zealand which forms a dense cushion of tiny needle like leaves that can resemble miniature grass for fairy and miniature gardens or railroad gardens. It will grown to a height of 2 inches (5cm) and a spread of two feet, but in the correct conditions, it hugs the ground and resembles a fine miniature grass or meadow. Hardy in zones 7 - 10, the plant will withstand winter temperatures of 0 degrees Fahrenheit or -18 Celsius, on well drained soils. Named varieties include 'Emerald' and 'Olive'. The plant has insignificant flowers. "Olive" appears to have finer, denser leaves than "Emerald", but is olive green to bronze green in color. All forms of Scleranthus turn slightly gold in winter. You can usually find this groundcover in the alpine or rock garden section of a nursery, where it is grown for it's small rounded cushion effect on well drained scree type soils.
Care of Scleranthus uniflorus:
Sclerantus grows in rock crevices and on sandy soils despite its resemblence to moss, and is a good candidate for miniature and fairy garden scenes in alpine troughs or planters. It prefers well drained sandy or gravel soils in full sun to partial shade. It should be kept evenly moist, and not be allowed to fully dry out for long periods. It does not like standing water or wet, spongy soils, especially during the winter months. In shade conditions it will grow looser and taller than it does in full sun.
Setting Sclerantus into a Miniature Garden Scene:
If you want your Scleranthus to resemble a grassy meadow in a miniature scene, plant it in well drained sandy soil, and press it down with your hand now and then as it grows to prevent it from forming small tussocks. It can be used as a grassy groundcover for scenes down to 1:24 or garden railroad scale. On railroad gardens you can step on the plant to flatten it, as long as it is planted in a soil with 'give', like sand. Each clump will eventually spread to roughly ten inches square, but to fill in a miniature scene, plant clumps close together and level up between the clumps with very sandy soil. To grow the plants into a grass like ground cover, keep them moist (but not wet!) and press down with you hands at least once a week to flatten the growth.
If left alone and not flattened periodically the plants will form small 'tussocks' or lumps. This does not damage the plant, but it does make the grass effect less formal for living miniature scenes.