How to Grow Strawberries
How to grow Strawberries
Strawberries are a popular choice, generally easy to grow and trouble free Strawberries require some time and attention to get a successful crop. Ideally, Strawberries are best planted in autumn, but Strawberries will grow well planted in the Spring although they may produce less fruit the first year. Strawberry plants fruit best in years 2,3,4 and then need replacing. Strawberries prefer good drainage which makes Strawberries ideal for growing in containers.( image below) From the white flowers, (image above ) the fruits will form, which are delicate and need protection against dirt splashes and birds. Strawberry fruit is prone to going moldy if it gets covered in dirty soil from splashes and the birds love strawberries as much as we do. If not protected they will peck at the fruit which damages it, and eat the crop. Some form of netting to protect the strawberries is essential see below.
How to plant strawberries
When planting Strawberries it is important to set the plant at the right level. The crown, which is the bit where the roots and stems meet, should be planted just level with the soil; do not plant too deep as this is one plant which, if the crown is buried under the soil may rot, particularly if the soil is not well drained or a wet summer.
The fruit needs to be protected from the soil and often a mulch of straw or hay is used. I like to use Strulch, which is a light, organic mulch ideal for strawberries. When growing strawberries it is an important step to take the time to cover the growing area with straw or a similar medium, as shown in the image above right. The plants need to be tucked in with the Strulch close the the plant, so the leaves and fruit are lifted above soil level. The image above right shows the strawberry bed mulched with Strulch.
Feed with liquid feed from spring onward if you have time, Tomato feed is ideal. When feeding and watering avoid splashing the leaves which encourages fungal diseases such as Botrytis.
If you are planting strawberries into containers, plant about 5 plants into a 30 cm/12" container. At the end of the growing season trim down all the leaves and runners (except those used for new plants see below) and feed. The plants will quickly put on new growth.
How to make an easy fruit cage.
Netting of some sort is inevitable because the birds will eat the fruit. Fruit cages can be expensive, but obviously as they are purpose built, very serviceable. Equally useful, and does the job, is a home made cage from bamboo sticks, simple connecting joints sold a DIY stores, (image below ) with net over the top secured in the ground by tent pegs. The netting needs to be raised above the strawberry plants, as the birds will still peck at the fruit if the net is on top of the plants, and the plants will grow through the net becoming entangled in the netting making it very hard to remove and pick the fruit. When making the cage push the bamboo canes in as far as they will go to withstand the summer gales.
Image below left shows the home made fruit cage which requires no DIY skills.
Best varieties of strawberries to grow
Strawberries which the RHS have tried and tested as giving good yields and flavours are 'Alice' 'Cambridge Favourite' 'Hapil' and 'Pegasus' together with those listed below as ideal for containers. I have also had good crops with sweet, tasty fruit from 'Albion' 'Red Gauntlet' along with 'Symphony' and 'Honeoye'
Best Strawberry Varieties for Growing in Containers
In 2016-2017 the RHS conducted trials to establish the best varieties of strawberries to grow in containers, which included hanging baskets and grow bags. There are some advantages to growing in hanging baskets and grow bags as they are raised off the ground which means the crop is kept away from ants, which can be a pest, there is better air circulation to reduce problems with Botrytis, and the fruit is cleaner when it is not directly on the soil.
Those which already have the RHS award are 'Cambridge Favourite' 'Honeoye', 'Pegasus', 'Rhapsody' and 'Symphony'. In addition for grow bags the trial found the best varieties to be 'Finesse' 'Florence' and 'Vibrant' and 'Evie 3' all of which have the AGM award.
A suggest variety for hanging baskets (none of which have the AGM) 'Delizz' (Liza) .
'Eros' and 'Mae' are reported to be more disease resistant, 'Elegance' and 'Sweet Colossus' large crops and fruit.
Growing Alpine Strawberries
Alpine and wild strawberries have become popular, even trendy. They are tiny delicate strawberries. If you do grow this variety, a word of warning. Strawberries are a vigorous plant and wild berries even more so. Some years ago I was given a batch of Alpine Strawberries and having at the time nowhere to plant them in a new garden not yet laid out, I temporarily put them in part of a border with a view to moving them later, which I did.
Years later I am still weeding wild strawberry plants out of the borders, where they root mercilessly, and are almost impossible to eradicate.
Strawberries are ideal for growing in containers including wild strawberries. As water and feed are more limited in a container, the Strawberries will need extra attention, more feeding and watering to ensure they don't dry out and will still need protection from the birds.
How to get an early crop of Strawberries
To ensure good fruiting strawberries do need a period of cold during the winter. By about February it is possible to warm up the soil and plants to bring on an earlier crop. Early in the season pick over the plants to remove any dead or diseased leaves and stray runners. Make sure the area is clear of weeds and it is a good idea to add some new compost. Cover the area with a cloche and early in the season I would also seal the ends of the cloche for maximum warmth. As the season warms up remove the cloche ends, and later remover the cloche altogether on warm days to allow the pollinators to get to the plants. It is also necessary as the season goes on to lift and water under the cloche to keep the plants well hydrated. Placing a cloche over the strawberries really does make a difference.
How to get Strawberry plants for free
As the season progresses Strawberry plants put out runners which are leads from the plants with a tiny plant on the end. This is shown in the image above in the centre. Mostly during the growing season it is advised to cut off runners to encourage the plant to put it's energies into fruiting not making more leaves. Later in the season these runners can be used to make new plants which given the short life of strawberries, 4-5 years, helps to replenish the stock of plants. Take the runner and plant either in the ground or put a small plant pot filled with good compost underneath. Leave for a few weeks until well rooted then cut off the runner separating it from the main plant. Grow on and pot on the small plant putting it into the strawberry bed replacing one of the older plants which is providing less fruit.
Problems with Strawberries
The main disease which can be a problem with Strawberries is botrytis, a form of grey mould which more of a problem in cool wet summers. Commercial strawberry growers often spray with fungicides to prevent Botrytis but the problem is more tricky for gardeners. Botrytis lives in dead plant tissue, which means that old strawberry leaves and leaf stalks provide material for the fungus to live on and to produce spores. The infection actually starts during the flowering period, (although it is not visible) although the disease remains inactive until the fruit begins to develop. It causes the fruits to rot as shown in the image below.
If Botrytis strikes it is best to cut off all infected leaves, together with any leaves showing signs of discolouration, and remove infected fruit. Clear up around all plants to remove any decaying leaves. To increase air circulation remove some extra (healthy) leaves, stake the plants to keep upright and allow the air to circulate and hope for a dry spell for the plants to recover. The images below show that you can cut off a good amount of the leaves, Strawberries are vigorous plants, and as you remove leaves you will see at the base of the plant fresh leaves growing so be bold and cut to try and stop the infection. Botrytis will attack all parts of the Strawberry plant and the fruit will rot before it ripens, very frustrating and given our propensity to wet summers it can be problem. As always with plant diseases, do not compost the leaves and waste material.
Strawberry plants only live for 4-5 years and so if it is a bad attack, and the plants are getting elderly, consider if this is time to replace them. More about this probelm Sunday Gardener's Blog Growing Strawberries and Botrytis