How To Grow Strawberries
Frost is the first thought when considering where to grow strawberry plants in your garden. They are very hardy plants during the winter, but are not so hardy when they burst into life in spring. Strawberries produce flowers early in the Spring, and because they are close to the ground it is important to position strawberries where they have the least risk of frost. The highest ground is always the best. When they first start into growth, frost damage will occur if the temperature drops below -2°C or -4°C without cloche or poly-tunnel protection.
Soil and Planting
Strawberries do not produce deep roots, but they very much appreciate their soil being well-dug to a spades depth. Prepare the soil at least one month before planting. Incorporate as much organic matter as possible and include two handfuls of bonemeal per square metre (yard). A few days before planting apply the recommended dose of general fertiliser such as Growmore. Strawberries are greedy feeders over a relatively short period of time.
If you are improving the soil in strawberry beds, it is best to do this during the late summer tidy up - as applying a nitrogen rich feed in spring will lead to vigorous leaf growth at the expense of the fruit.
As regards summer feeding, avoid excess nitrogen as mentioned above, but use a high potash feed if plants need a boost from flowering time through to harvest: tomato feed is ideal. My own regime is to add seaweed and poultry manure pellets at 150g per square metre in late summer, and leave it at that - a well fed soil generally doesn't need any extra feed, provided plants are adequately spaced.
New plants can be propagated by pinning baby plants growing on runners into a pot of compost and letting them root. After a week or two, the runner can be cut and the pot - now containing a brand new strawberry plant - removed and planted elsewhere.
Bear in mind that strawberry plants will decline in productivity after about 3 years. You should continually replace any older, tired looking plants with fresh ones to keep your strawberry patch producing decent sized fruit. An overcrowded strawberry bed will also result in smaller fruit, as plants compete for water and nutrients - so you should aim to keep your spacings around the same as they were when you planted them, i.e. 45cm apart in rows 75cm apart. Strawberries are tough, so don't be concerned about digging them up and moving them. Just make sure you re-plant the healthiest looking plants.
As the fruit begins to develop, their weight will cause them to lay on the ground. Before this happens (but no earlier than necessary), cover the soil around the plants with either straw or black plastic. Where plastic is used, it can be kept in place with stones - small holes should be made in the plastic to allow drainage and to stop water gathering on it. The plastic or straw will prevent the fruits from lying directly on the soil, which will rot them.
If you have a bird population in your garden, the plants should be protected (when the fruits begin to swell) with lightweight plastic netting. This should be held clear of the plants by tying it to short wooden posts and securing the netting to them. Wire mesh can also be used, held in place by canes at either corner. A more permanent and effective solution to bird damage for many fruits is a fruit cage.
Strawberries will naturally die back in winter, but there is no need to trim leaves off unless you want to tidy up for aesthetic reasons.
Leaving a mat of dead or dying leaves will help protect the soil over winter. The only downside is that you may be creating habitats for slugs - but the beds should be cleaned in late winter/early spring anyway, when any unwelcome residents can be removed.
The best time to tidy up strawberry beds and to propagate new plants is just after the fruiting season (around mid July). They will also benefit from some attention before the growth starts again in early spring. In late summer you can remove any dead or weak looking plants; cut back older leaves on healthy plants to 3 inches above the crown, leaving the new leaves in place.
In late winter and early spring you can attend to any tidying jobs required including any of the above (apart from propagation). I would hold off mulching plants with straw, as is often recommended, until the fruit has set and started to swell. The mulch's primary function is to keep fruit off damp soil, so it's better to add a fresh mulch when needed rather than letting it rot down and/or provide a slug habitat.
Diseases and Pests
The major pests and diseases of strawberries are aphids, red spider mite, slugs, powdery mildew and botryitis.