Read at :
Royal Horticultural Society
http://www.rhs.org.uk/thegarden/pubs/garden0101/jan_strawberries.asp
The Garden
January 2001
Pot the red
A handful of strawberry plants can yield a bumper crop of fruit. Jim Arbury recommends a variety of suitable containers
Jim Arbury is Superintendent of the Fruit Department at RHS Garden Wisley
Sweet and versatile, strawberries are the essence of a British summer and delicious when eaten freshly picked. Strawberry plants will yield good crops of fruit when grown in small spaces including a wide range of containers, and growbag cultivation is particularly economical and productive. The small, short-lived perennial plants are suitable for autumn or spring planting, and a little extra time spent now in caring for your autumn-planted runners and finding the right location to grow a container of cold-stored strawberry plants will help to improve your chances of a bumper summer harvest.
Strawberries grow well in the ground, but they can suffer from soil-borne pests and diseases if grown on the same patch for a number of years. Where space is at a premium, strawberries will also fare well for a year or two in grow bags, troughs, pots and hanging baskets, and this approach has several advantages over plants grown in the open.
Strawberries in containers can be given a prime position - they prefer a sunny but sheltered spot and being raised off the ground, which helps to produce a more stable microclimate. Containers can be brought under protection (such as a glasshouse or porch) to advance fruit cropping and then replaced once fruiting is over. Container-grown strawberries also suffer from fewer problems with soil-borne pests and diseases, and are at a more convenient height for picking.
Planting considerations
When preparing pots for planting strawberries, use soilless composts or those with a low loam content, as these weigh less and make heavy containers such as large terracotta strawberry pots more portable.
Plant freshly dug runners from August to mid-September to allow proper establishment and a good crop in the first summer. Cold-stored runners can be planted in spring but the crop may be less successful. Always use stock that is certified virus free.
Water by hand or via driplines, varying frequency according to the time of year, season and position of the containers. Strawberry plants in grow bags, pots, troughs and hanging baskets should remain moist but not waterlogged, and may require watering more than once a day in the hottest conditions.
As soon as growth commences in spring provide a balanced liquid feed (with similar levels of nitrogen and potassium) each week. During flowering and fruiting use a high-potash feed such as a tomato fertiliser, then revert to a balanced feed if the plants are to be kept for a second year. Strawberry plants that are overfed will produce lush leaf growth at the expense of fruit.
A winter chilling will help plants flower effectively. Keep the containers at ground level in a sheltered situation and if severe frosts are forecast cover with frost protection such as horticultural fleece or straw, which should then be removed during the day.
