HOW TO GROW CHRYSANTHEMUM FROM SEEDS

HOW TO GROW CHRYSANTHEMUM FROM SEEDS

Mums (Chrysanthemum x morifolium) brighten autumn gardens with their cheery flowers. They are typically grown as annuals, although mums are technically perennial within U.S. Department of Agriculture plant hardiness zones 5 to 9. Although most commonly propagated from cuttings or divisions, mums will also grow readily from seeds in just 10 to 15 days. However, the seeds must be started at the right time of year and kept under appropriate conditions to perform their best.

Timing

Mums take up to four months to flower from seed, so it is best to give the seedlings a head start by sowing them indoors in early spring. Start the seeds roughly eight weeks before the last spring frost, which is mid-February within Mediterranean climates. The seeds can also be started outdoors anytime from after the last spring frost until two months before the first autumn frost. However, the seeds germinate less reliably when sown outdoors due to temperature and moisture fluctuations in the soil.

Sowing

Light exposure is key to successfully germinating mum seeds, so they must be sown at the appropriate depth. Sow two or three seeds in each pot by lightly pressing them onto the surface of the soil. Spread a very thin layer of soil on top so they are covered but still somewhat exposed to the light. Dry soil may shift during watering, so mist the surface with a spray bottle and gently tamp it down to increase contact with the seeds.

Germination

A warm, bright room with south- or west-facing windows provides the ideal conditions for germinating mum seeds. Arrange the pots within 3 feet of a window. Unless temperatures stay reliably above 70 degrees Fahrenheit, warm the pots with a heating coil or propagation mat and keep them covered with plastic wrap. Keep the top 1 to 2 inches of the soil moderately moist during the germination process using a spray bottle. If the room receives less than six hours of bright, natural sunlight each day, suspend a fluorescent grow lamp 12 to 15 inches above the pots to supplement the available light. Closely monitor the moisture level in the soil when using a heating coil or fluorescent lamp because artificial heat will cause it to dry out faster.

Aftercare and Planting

Once sprouted, mum seedlings quickly put on growth, so the emergent seedlings must be thinned out promptly to prevent overcrowding. Remove the spindliest seedlings from each pot and leave the most robust one. Water at the base of the seedlings, taking care not to splash water onto the leaves. After the last frost, move the mum seedlings to a sheltered and lightly shaded area outdoors to harden them. Leave them out for a few hours each day, gradually increasing the length of time over the course of two weeks. Transplant them 12 inches apart in a sunny bed with rich, fast-draining soil once the soil warms up.

Considerations

Although mums grow readily from seed, they readily cross-pollinate and, as a result, the seeds may not produce a plant that resembles the parent plant in flower color, composition or growth habit. Most seed propagation is done solely to create new mum varieties and it is not advantageous to home gardeners. Clonal methods such as cuttings provide the only reliable means of reproducing a particularly attractive or hardy mum variety.