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Fresh strawberries for dessert, or jam-making on the weekend? These are the tough choices facing the home strawberry grower.
Every October we harvests a kilo every second day from the family strawberry patch, this is how it's done.
Strawberries need sun, good drainage and plenty of organic matter. In winter protect plants in very cold areas with a covering of straw. We’ve experimented with strawberries in pots, raised timber sleeper beds and water tank garden beds. The latter technique was most successful, primarily because it was easiest to protect the fruit from lizards and birds. Strawberries can also be grown in foam vegetable packing boxes. Put eight drainage holes in the bottom of the box then fill with a premium potting mix. You can also develop a strawberry patch in open ground, but don’t plant them where tomatoes, eggplants, potatoes or raspberries have been growing during the last five years, as the pathogen verticillium can debilitate them.
Generously add blood and bone and cow manure to the soil before planting. Plant new plants during winter or spring, or plant from runners in autumn. The crown of each plant, which is the swollen stem base, must be left at the surface of the soil and not buried too deep. Plant 30cm apart.
Grow a large range of strawberries to ensure a picking season from October to May. If you're starting from scratch, buy seed or certified disease-free stock. We started with the Digger’s Strawberry Japanese Collection, which comprised 10 ‘Kunawase’ and 10 ‘Hokowase’. We also included ‘Chandler’ and ‘Cambridge Rival’, plus a few ‘Temptation’ and ‘Alinta’ which crop into winter.
You cannot over feed strawberries! We alternate weekly foliar and ground seaweed spray, with homemade comfrey tea. You could also use a fruit fertiliser high in potassium. Strawberries have shallow roots and are prone to drying out so ensure regular watering. Weed control is vital through the growing season.
Over summer the strawberry plants send out runners from the original or mother plant. These modified shoots can be used to propagate new plants. If you don’t need new plants, cut the runners off. After fruiting has finished, tidy up the bushes by giving them a hard prune down to 10cm. After four years, mother plants become underproductive and can be pulled out and replaced with one of the runners.
Estimate a yield of about 5kg of fruit from just 10 plants. Pick the berries at about three-quarters red using scissors to snip off the fruit so that it isn’t bruised. Keep a look out as it ripens quickly.
Powdery mildew, a fungus that causes a whitish-grey powder on the leaves, can affect strawberries. Treat plants with fungicide or regularly apply a milk spray (one part milk to nine parts water). Full sun and good air circulation reduces the risk. Also remove all dead leaves and keep the soil mulched. If you notice aphids, control with soapy water or pyrethrum spray immediately because aphids can transmit viruses. Birds are also a problem, but as the strawberries only grow 30cm high, the garden bed can easily be covered with bird netting strung over wire arches.
Where to buy
Popular varieties are stocked by local nurseries. Diggers has two separate collections.