How Long Does It Take for Nasturtiums to Grow?

Germination

• If you grow nasturtiums from seed, you should have visible seedlings 14 days after sowing. How you prepare and plant the seeds directly affects how long they take to germinate. You should soak your nasturtium seeds before planting them -- this helps the thick seeds absorb moisture to stimulate germination. It also helps to nick the seed coat's surface with a blade to stimulate growth. Sow your seeds in a container or directly in the garden in spring. The seeds need to be covered with 1/2 inch of soil to properly germinate. Maintain a 12-inch spacing between each seed to allow for ample root spread and foliage growth.

Summer and Fall Flowering

• Because nasturtiums are annuals, they must grow and flower quickly for successful reproduction. As a result, your well-prepared seeds should produce dense stems, foliage and flowers after approximately two months -- roughly 55 to 65 days. In general, non-spreading nasturtiums typically grow 24 inches tall and wide, while climbing types spread to 72 inches long, up a support. To keep your nasturtiums flowering, consistently pick the flowers for indoor bouquets. Your plant generates new flowers to compensate for the loss to increase reproduction success until fall turns into winter. If you live in a mild winter climate, grow nasturtiums as winter annuals.

Soil Influence

• Nasturtiums do not have strong taproots to move through compacted soil -- their fibrous roots need loose soil to spread. These plants thrive in sandy soils with little fertilizer. Adding excessive fertilizer to the soil only encourages foliage growth at the expense of flowers. Blooming is also directly influenced by sun exposure. Grow your nasturtiums in full sun so they can produce the energy to provide plentiful flowers and lush foliage.

Drought Issues

• Because nasturtiums prefer sandy soils, it is possible for moisture to move too quickly through the soil. Your nasturtiums may suffer from temporary drought because the roots cannot absorb the moisture as fast as it is lost to drainage and evaporation. In summer, water your nasturtiums consistently to keep the roots damp, but not soggy. Drought stunts nasturtiums and causes stress -- you may see flower buds dropping or foliage dying back if dry conditions continue.