Germination of the Giant Ray Aster

Timing

• Giant Ray asters grow moderately fast but are sensitive to cold, so give them a head start before planting them in the garden. Start the seeds indoors six weeks before the last spring frost so they have enough time to develop a healthy root system and plenty of foliage before living outdoors. In relatively frost-free climates above U.S. Department of Agriculture plant hardiness zone 10, the seeds can be started in late summer and planted outside in fall to brighten up winter gardens.

Equipment

• The right equipment is essential when starting Giant Ray aster seeds. Biodegradable peat pots, unused potting soil and a spray bottle are vital, but a heating coil or germination mat may also come in handy if indoor temperatures routinely fall below 70 degrees Fahrenheit. Fill the peat pots with slightly moist potting soil, leaving the top 1/2-inch of each pot empty. Plastic wrap draped over the pots will help maintain a warm and humid environment for the seeds.

Sowing

• Because Giant Ray aster seedlings resent being disturbed, sow only one seed in each peat pot to avoid the overcrowding that leads to transplanting. Position the seed on the soil near the center of the pot, then gently press it. Deep sowing inhibits germination in Giant Ray aster seeds, so cover them with a layer of soil no thicker than 1/8-inch. Mist the soil heavily after sowing, and lightly tamp it down.

Germination Process

• Bright light, adequate moisture and consistent warmth will prompt germination in Giant Ray aster seed within 10 to 14 days of sowing. The seeds should receive at least six hours of bright sunlight each day, so position them near a large, unshaded window with southern exposure. Cover the pots with plastic wrap before placing them on a propagation mat set to 70 degrees Fahrenheit. Water the seeds to a 2-inch depth using a spray bottle when the soil dries out on the surface. Avoid overwatering and letting the soil dry out completely because either can cause the Giant Ray aster seeds to fail.

Aftercare and Planting

• Indoor living will inhibit growth in Giant Ray asters, so it is important to move them outdoors immediately after the last frost. Place the seedlings in a sheltered location with light, midday shade. Continue to water when the soil surface dries out. Before planting in the ground, slowly acclimate the asters to the outdoor location's normal humidity, temperature and light. This will limit the chance of shock. Gradually expose them to stronger sunlight and while reducing watering for one week before planting. Plant them 6 to 9 inches apart in a sunny bed with rich, well-drained soil and watch for the first blooms in roughly two to three months.