When should you sow Japanese lanterns seeds and how deep should they be sown?
The Gardener’s Answer
Hello, Terri in Kentucky: There are several species of Physalis, commonly known as Chinese or Japanese lanterns. All belong to the nightshade family but some of these species are annuals and others are perennials here in Kentucky. The annuals have a taproot and the perennials form a thick underground mat known as rhizomes. The perennials can be aggressive and considered weedy. Do you know which species you have? If you purchased them in a seed packet, it will tell you the species. P. alkekengi, P. heterophylla, P. longifolia, and P. virginiana are all perennials here in Kentucky. Annual species include P. angulate, P. grisea, P. pubescens, and P. philadelphica. As for planting seed, you can start them indoors now and transplant the starts into the garden in May, or you can wait until the frost-free date for our area passes, usually around May 10, and directly sow them outdoors. Sow them ¼ of an inch deep and make sure the soil remains consistently moist. Too much water can rot the seeds and too little will prevent them from germinating. Depending on species and growing conditions, they should germinate in 14-30 days. Indoors they should receive as much light as possible, and if you directly sow them in the garden later this spring they should be planted in a sunny location. The colorful lanterns form around a single berry after the flower has been pollinated. They are great for cut or dried arrangements.