Perennial Impatiens The flowers are long lasting, blooming in spring and staying bright until the first frost. Perennial impatiens can grow up to 2 feet in height and have a spread of 2 feet. While live plants are usually easy to find, they can also be started from seeds as early as 8 to 10 weeks before the last frost.Click to see full answer. Furthermore, how do you keep impatiens blooming? This can be done with a few simple steps. Keep Watered. Impatiens love water. Impatiens Love Shade. Impatiens do very well in shady areas. Enrich Soil with Humus. Keeping blooms all summer takes a lot of energy. Pinch Back Blooms. Reapply Fertilizer. Prune Off Top Third of Plant. Prepare for Next Planting Season. Also, why do my impatiens have no flowers? You never want your soil to dry out completely. If your impatiens won’t bloom, it may also be due to over fertilization. A lot of fertilizers are high in nitrogen, which is great for foliage growth but bad for flower production. Overzealous pruning may also be the cause for an impatiens with no flowers. Beside above, how long will impatiens last? Blooms can last 210 days a growing season if impatiens are planted in locations that have long summers, according to the University of Mississippi. At the end of the summer, flowers start to go into dormancy. The first frost will mark the end of your blooms.How do you keep impatiens over winter?A: There are three ways to keep your impatiens. You can simply dig a clump of the plants and keep them in an indoor pot for the winter. You’ll need to grow them in plenty of light to keep them healthy. Another option is to take 6 inch long stem cuttings and root them in water.