Apparently the modern Strawberry comes from the Americas, and the hybrid was created by Europeans crossbreeding wild varieties from both North and South America.
The so called perpetual fruiting varieties, (actually usually three flushes of fruit), are better value than the traditional single flush types as they spread the fruiting period over several months. As you are growing your own, you can pick them when they are really red and properly ripe, with that wonderful aroma.
The plants are easier to protect from slugs, snails, mice and birds, if grown raised up some 60 cm above the ground in old fish boxes or similar boxes, or even 60 litre grow bags. Grow 8 plants to a box or growbag and arrange the fruiting shoots to hang over the edge of the box. This technique is particularly worthwhile when growing “perpetual fruiting” varieties, as it is easier to provide protection against birds and rain and extend the fruiting period as much as possible. In Glasgow, I still get a few fruits into November, but they do tend to be smaller and not so sweet as the earlier crops. Commercially, this is the system that is being used for much of the crop grown in poly tunnels.
Providing you have deep boxes, say 30 cm, they do not seem to dry out too fast. Try filling the box with old grow bag compost (not from tomato plants), for the bottom half to provide a moisture reservoir, and then fill up to the brim with sieved compost or soil. You will need to keep an eye out to prevent the boxes drying out, and water accordingly. Feeding with tomato fertilizer every month after growth starts gives good results, as it has a high Potash content.
If you are growing your strawberries at ground level in the traditional way, consider planting them on top of raised mounds to prevent the fruit sitting on sodden ground after heavy rain. If you also plant them through a weed suppressant fabric, it should eliminate the chore of keeping the plants weed-free, and make it less inviting to slugs and snails. It should also keep the strawberries from direct contact with the ground.
Traditionally, straw was spread around the plants to keep the strawberries off the soil. However, I cannot remember the last time I saw straw for sale, though you could try a pet shop. I have found old wire shelving from fridges quite useful for allowing air to circulate underneath the fruit. Use a high potash fertilizer.
But overall, growing the strawberries in raised boxes as described in the previous section, will enable you to harvest a much better crop, that has not been ravaged by slugs, snails, mice, rats. .
For the earliest crop of strawberries grown under polythene or in a cold frame or greenhouse, remember that strawberry flowers require to be pollinated by bees. Therefore you should allow the bees access to the strawberries once they start to flower. It is usually Bumble Bees that do this work for my Strawberries. Alternatively, you can try to pollinate by hand with a fine brush, but this is liable to produce distorted fruit. Nature does it best! Commercially, growing strawberries under polythene, they introduce mini-hives of Bumble Bees into the polytunnels.
Strawberries are best picked and used fresh as soon as possible. They should be picked keeping a little bit of the green stalk attached, to prevent any danger of mould affecting the individual strawberries. They should keep for a few days in a fridge.
For long term storage, and for future use in cooking, jam making or ice cream, the second quality strawberries should be washed and “hulled” (have any green stem removed with finger and thumb), before being frozen. While the texture on defrosting will not be as good as when used fresh, it will not be noticed when the fruit is used for cooking.
Pests and diseases. Watch out for the grubs of the Vine Weevil, which will devour the roots. It is usually noticed when the plant collapses, even after watering. The only licensed treatment is the application of nematodes. NB “Provado” Vine Weevil killer must not be used on edible crops.
Botrytis, a fungal disease, can be a problem in damp, mild weather. If growing in raised boxes, there is more movement of air around the fruit, and less botrytis.
While not a disease, late frosts can cause damage by causing the centre of the open flower to go black and die. Hopefully, more flowers will appear to give you some fruit. If frost is forecast, cover the plants with fleece or plastic.
Maintenance of your Strawberry bed. At the end of the growing season, tidy up your Strawberry plants, by removing all the old leaves and rooted runners with scissors. Unfortunately, there is a tendency for Strawberry plants to revert to stunted specimens and die after about three years. Therefore it is best to restock your Strawberry bed in different soil, using “runners” from healthy plants, that you have saved and potted-up during their growing season.
New Strawberry bed. Every three years or so, the strawberry plants become small and unproductive. It is now time to start a new strawberry bed in fresh soil, using bought in bare root “runners”, or bought in potted plants, or from home grown plants produced by potting-up “runners” the previous Summer and Autumn. A strawberry plant sends out runners during the growing season, which will root and form a new plant.
The new plants in the open ground should be spaced at 45 cm apart, with the rows 75 cm apart to allow access.
Provided you keep your new plants well fed and watered, you should be able to get a small crop of fruit in the first growing season. However, to conserve the strength of the plant, remove any runners that form during the first growing season.
Suggested varieties of strawberries.
Flamenco. Everbearer flowering with vigorous growth. Heavy crops of sweet fruit.
Strawberries from seed.
Varieties of strawberries are now available for growing from strawberry seeds, and this can be surprisingly successful. Providing that you start sowing the seed early in February in cells in heat, it is possible to harvest the first strawberries in July or August of the same year. The plants grow very slowly at first but eventually start flowering.
Suggested varieties of Strawberries from seed.
Florian F1 An everbearing type with very sweet fruit.
Wild strawberries are small compared to modern cultivated varieties and not sweet, but are frequently used as garnishing for sweets.