It is possible to grow strawberries indoors with the proper lighting and soil. You can grow strawberries in the winter, or all year round if your climate is not suitable to grow them outside. Strawberries grow as well in containers as they do when planted in the ground. The everbearing strawberry plant produces crops of strawberries in the summer and again early fall. This type of strawberry plant is ideal for a hanging basket. Only the strawberry plant itself should be planted. If you choose to keep the runners to plant in the spring, they should be placed in a greenhouse during the winter months.
TIP: Our expert gardening advisor, Rachel Klein adds, "Depending on the type of berry, you may have plants that send out runners like crazy. You can either plant the tip of the runner in a new pot and cut it when the new plant begins to sprout, or simply prune them off if you have enough plants already."
Prepare the Strawberries for Planting
The strawberry plant should be cleaned up before planting. Old leaves should be removed as well as the runners, the roots should be trimmed to a length of approximately 4 to 5 inches. If there are any damaged areas on the plant, they should also be removed. The roots should be soaked in water for an hour or so before planting.
TIP: Rachel advises, "The Red Alpine strawberry is a great everbearing variety to grow indoors because they do not produce runners and make a very neat potted plant."
It is possible to grow strawberries inside by seed. Buy your strawberry seeds at a nursery or online. If you use the seeds of store bought berries you will not know what type of strawberry it is, and your plant may have a limited harvest or grow large and unruly. After buying your seeds, place them in the freezer for 2 weeks. This will jump start your seeds once planted because it simulates winter weather. Prepare a seed tray with 1/2-inch soil, 3/4 peat moss and 1/4 potting soil. Dampen the soil mixture and sprinkle your seeds on top if it. Add a light dusting of peat moss over top of the seeds, but not too thick. Keep the seeds moist and in direct sunlight. They should take 2 to 3 weeks to germinate. Once they have grown their third set of (true) leaves, they are ready to be transplanted to your containers. Strawberries started from seed will produce berries in their second year.
Prepare the Container or Hanging Basket
The best soil for growing strawberry plants indoors has a PH between 5.3 and 6.5. A controlled-release fertilizer should be mixed in with the soil so the strawberry plants will get enough nutrients while they grow in a pot or basket.
Use approximately 24 strawberry plants for a 16 inch basket. If you are using a wire basket, line the wire basket with sphagnyum moss, coconut fiber or a basket liner. You can also use a traditional strawberry pot. Plant 1 strawberry in the smaller pockets and up to 10 in the center opening, depending on the size of the pot.
TIP: Rachel says, "Choose a sunny south facing window, or an enclosed porch that receives bright sunlight. If you don't have a spot that gets enough sun (at least 6 hours a day) you can use artificial light, specifically compact fluorescent light. The plants should be exposed to the artificial light for 12 to 16 hours each day.
Plant the Strawberry Plants
Place 18 of the plants to the sides of the basket, through the moss. Fill the basket with potting soil and then plant the remaining strawberry plants in the top center. A basket like this should be capable of producing strawberries for at least 3 years.
Make sure that the crown of the plant is even with the soil surface, and that the roots are fanned out in the soil. The plant will not grow well if it is planted too deep or if the roots are not spread out.
Care for the Strawberry Plants
During the first 6-weeks, any blossoms need to be pinched or cut off. This ensures that the strawberry plants have enough time to get accustomed to their new environment before using up all their energy to grow the strawberries. The plants should be watered daily until the plants start to produce, sometime after the 6-week period. At that point, water only when the top inch or so of the soil is dry.
TIP: Rachel adds, "Although uncommon, it is possible for your indoor berries to become infested with pests such as red spider mites and aphids. Use a natural pesticide, or make your own out of soap and water. Mix 1 part organic dishwashing soap with 15 parts water and spray your plants thoroughly."
The plants should be fertilized at least once a month. Organic fertilizers such as a sea weed-fish blend are ideal. They should have at least six hours of sunlight each day. Strawberries can be picked as soon as they have turned red.