By Annie Klodd, Extension educator, fruit and vegetable production
Strawberries are a great choice to fill your pots, planters, hanging baskets or maybe even window boxes. The plants are compact and the berries hang beautifully off of the edge of the container. As long as you choose the right type of strawberries, they can be removed at the end of the season so you don’t have to worry about where to put them over the winter.
There are two types of strawberries: day-neutral and June-bearing. Only day-neutral strawberries are truly well-suited for containers. These are also commonly called “everbearing” strawberries.
So, the first tip for planting container strawberries is to make sure you purchase day-neutral plants and not June-bearing plants.
Tip #1: Choose the right plants
Day-neutral strawberries produce fruit all summer, from July through October or the first frost.
One thing that makes them great for containers is that they are usually grown as annuals – we remove the plants at the end of the season and plant new ones the next year, just like with annual vegetables.
Find day-neutral (everbearing) strawberry plants in local hardware stores, garden centers, or online seed companies and nurseries. In stores, they are sold in bags of 5-10 and are displayed with seed potatoes and asparagus crowns. Online, you will often find them in sets of 25 for around $25.
They are sold as dormant bare-root plants — just a ball of roots connected to a couple of small dormant leaves. Sometimes, you can also find potted plants in garden centers, but these are much more expensive and don’t really have any advantages.
Look for these varieties: Albion, Seascape, Evie-II, Monterey, Portola and San Andreas.
Do not grow June-bearing strawberries in containers unless the containers are very large, like a wood-framed raised bed. They are perennial plants and have to have space to spread and reproduce, otherwise, they will only produce fruit for one season before declining. Also, they do not produce fruit until a year after planting.
Tip #2: Find some sun
We might sound like a broken record saying this, but fruit crops really do need full sun. Place your containers where they get full sunlight for at least eight to 12 hours per day.
It takes a lot of energy for plants to produce large, flavorful berries, and they need sunlight to achieve this. Select a south-facing side of your home or find a spot away from shade trees or buildings. Window boxes can be perfect for strawberries, as long as they are in full sun.
Tip #3: Reach for the good potting mix
Day-neutral strawberries produce more, larger berries when they grow in well-drained soil with plenty of nutrients.
Use a potting mix meant for containers, and mix in a fertilizer containing nitrogen, phosphorus, and potassium (N-P-K) before planting. You may sprinkle on a small amount of nitrogen-containing fertilizer mid-season to give the plants a boost. Follow instructions on the fertilizer label to ensure you are not over-applying it and potentially burning the plants.
Tip #4: Give them just enough space
Plant day-neutral strawberries about eight inches apart in the container. They may be planted six inches apart if staggered in a row.
Because they can be planted relatively close together, they pack a lot of fruit production into a small space. Each plant will produce about a half-pound to a pound when grown in full sunlight with adequate soil conditions and water. If large fruit is your goal, try planting them slightly further apart.
Tip #5: Don’t forget to water!
Strawberries need regular watering to keep producing strong yields of large fruit all season. In fact, strawberry farmers irrigate their strawberries with drip tape or sprinklers to make sure they are getting at least one inch of water per week.
Water at least twice per week, or more during the mid-summer when temperatures are hot and the plants are growing rapidly. Check the soil moisture daily by sticking your thumb into the top inch of soil. If the top inch is dry, apply water. You also can use a soil moisture meter to develop a more precise watering regimen.
For more information on growing strawberries, see extension.umn.edu/fruit/growing-strawberries-home-garden.