The taste of home-grown strawberries is far superior to their shop bought counterparts; fortunately, they are easy enough to grow in raised beds, containers or even in the greenhouse with the right care and attention. If raising strawberry plants in a greenhouse, here is everything you need to know to ensure healthy, thriving crops.
To ensure the best chance of success for your greenhouse strawberry crops, choose certified plants. Mature plants tend to cope better with the heat and humidity levels of a greenhouse than runners, although some varieties of young strawberries, such as Tamela, will grow happily in containers in your greenhouse. If you start off young plants or runners in a greenhouse, place them in a clear bag or humid propagator until the roots have established – they will struggle to thrive in very hot conditions and will demand high humidity levels.
Strawberries thrive on nutrient-rich, acidic, well-drained soil. Place individual plants in containers or grow bags, using compost or soil high in organic matter. Ensure there are sufficient drainage holes in your containers – strawberries do not like sitting in water-logged soil, which can damage the crown and cause the fruit to rot. Add a layer of mulch or straw around the surface of the plant to keep the roots cool and the fruit free from moisture.
Heat and light
Strawberries favour heat and as much sunlight as possible, so make sure that the windows of your greenhouse are clean and there is nothing in the way to block out any light; ideally, they should get at least six hours of sunlight daily. Until the plants begin to flower, maintain the greenhouse temperature at around 60°F. The beauty of growing strawberries in a greenhouse is that you will not need to contend with frost, especially an unexpected late frost. Once you have harvested the strawberries, reduce the temperature in the greenhouse so that it remains cool during winter; a cool period is necessary to encourage the plants to flower the following season.
Watering and feeding
Since greenhouses can get very hot, and strawberry plants have shallow roots that dry out quickly, regular watering is important, especially during summer. Avoid over-watering the crown or fruit, however, as this can cause rotting. Water from the bottom of the plant if possible; if you can only water from above, do so in the morning to minimise the amount of time they remain wet. Until the flowers open, feed the plants with an organic liquid fertiliser every two weeks or so.
Growing strawberries in a greenhouse keeps them better protected from attack by pests such as slugs, snails, rodents, insects or birds. They are also less likely to succumb to diseases, although this is still a possibility. Keep your greenhouse clean and be vigilant for signs of disease to prevent problems spreading. Strawberries can be prone to verticillium wilt; however, you can prevent this by choosing certified varieties and keeping them away from other plants – such as tomatoes – that are susceptible to this disease.