How To Grow Strawberries In Containers And In The Ground
Strawberries are a summer essential, sweet and juicy, and easy to grow
Strawberries warmed by the sun and eaten straight from the garden taste nothing like those from the supermarket; they have an intense flavour and sweetness and are full of juice. Celebrate summer in style with a couple of pots or a patch of strawberries. They are easy to grow; the main thing to remember is to keep them watered. There are lots of varieties from which to choose, from the small intensely sweet to the large heavy croppers, which sometimes sacrifice flavour for quantity, and don’t forget the tiny wild or Alpine strawberries. Buying from a reputable supplier will give you peace of mind that the plants are correctly named and free from disease.
They will grow well in the ground, containers, hanging baskets, raised beds and growbags. Beechgrove Garden in Scotland had the brilliant idea of growing them in lengths of large diameter guttering pipe raised off the ground to waist height on a timber X frame with a seep hose running the length of the pipe. This had the advantage of growing in a polytunnel to get an earlier crop, they were away from slugs and you didn’t have to break your back bending down to pick them. If space is at a premium you could plant underneath the strawberries which are raised off the ground with low growing crops, such as dwarf beans, lettuce, radish, onions or beetroot.
They need a sunny, sheltered site with fertile, well-drained soil. If the site is windy you could have a problem with pollination as the wind could be too strong for insects to fly. Make sure the ground has not previously grown potatoes, tomatoes or chrysanthemums as they are prone to verticillium wilt and it could be lying dormant in the soil.
If you are buying bare-root runners plant them as soon as you get them in early autumn, any later than this and they can be potted up and planted out in spring. If they are pot grown you can plant these as soon as the soil warms; don’t plant them if the soil is cold and wet. If you are planting them in containers or hanging baskets these can be planted as soon as you buy them and kept under cover. Use good quality peat-free multi-purpose compost. If growing in a growbag use one specifically for strawberries. Planting at the right depth is crucial otherwise you will lose the plant. Make sure the crown is level with the soil surface; too deep and the crown will rot, too shallow and it will dry out, in both cases the plant will die. Cut off any old leaves, runners and flowers, this will concentrate the energy into building a strong plant.
Plant them 35cm (14”) apart in rows which are 75cm (30”) apart.
Putting down a permeable weed-suppressant membrane then planting through it will keep the berries clean and save a lot of time weeding in summer, it will also stop weeds competing with the strawberries for nutrients. If you don’t plant through a membrane put a thick mulch of straw under the plants once the fruits start to form, keeping it away from the crown, this has the same effect of keeping the fruit clean and the weeds at bay.
Water them frequently taking especial care if they are in containers as these will dry out quickly in summer, so may have to be watered twice a day. Water the plants in the morning so the leaves have time to dry out; this will reduce the likelihood of getting fungal problems. If possible don’t water from overhead; a drip irrigation system would be ideal as this delivers a steady trickle of water directly to the roots. Watering overhead can lead to the crown and fruit rotting. Keep weeds down as they will compete for nutrients and water. In an established strawberry bed lightly fork in Growmore at a rate of 50g per sq m (2oz per sq yd) in spring. Feed fortnightly throughout the growing season with a liquid high potash fertiliser, such as Tomorite. At the end of the fruiting season remove the straw mulch as it will provide an overwintering site for pests. The plants will only be productive for about 3 years so after this time they will need replacing, either by buying new plants or letting the established plants grow runners. Peg the little plants these runners produce down into a 9cm (3”) pot of multi-purpose compost without severing from the parent plant. Once they have grown into a decent sized plant then they can be severed from the parent and grown on in a cold frame or unheated greenhouse.
Growing under cover
Covering the plants with a cloche in early spring will produce fruit 7 – 10 days earlier than if it was left uncovered. Once they start to flower you will need to roll up the sides to allow access for insects. Growing the plants in an unheated greenhouse will produce fruit 10 – 14 days earlier than if grown outdoors. If you grow strawberries in a heated greenhouse take care not to let the temperature rise above 16C (61F) as temperatures above this will inhibit flowering. It will probably be necessary to hand pollinate the flowers as there will be very few insects.
Harvest when all the berry has turned red, if there is white around the stalk they could be a bit hard. Try and harvest on a warm sunny day as this is when they are at their most tasty. Eat immediately as they don’t keep well; if this is not possible either freeze or preserve them. Home-made jam, sorbet and ice-cream are so much better than shop-bought items.
Pests and diseases
Red spider mite can be a problem in the greenhouse. They like hot dry conditions so ensure that you keep misting regularly and keep the path damped down. The symptoms are pale mottled leaves and if you lightly mist the leaves you will be able to see the webs. Spray with an insecticide specifically for fruit and vegetables, repeated applications may be necessary as they are not that easy to eradicate.
Birds are one of the biggest problems as those big fat juicy berries are irresistible not only to us! Either grow them in a fruit cage or cover with bird netting after the flowers have been pollinated.
Powdery mildew is a whitish powdery deposit on the leaves which is exacerbated by warm dry conditions so keep the plants well watered and the soil cool by putting down a mulch.
Grey mould is a result of wet conditions and poor airflow so make sure you water onto the soil not the plant and don’t plant too close together. Remove and destroy any infected material; don’t put it on the compost heap as this will only spread the problem, put it in the grey bin or on the bonfire.
There are three types of strawberry: perpetual, summer fruiting and wild or Alpine.
Perpetual strawberries tend to produce smaller berries periodically from early summer to early autumn.
‘Aromel’ - good strong flavour
‘Finesse’ - produces a high yield with good flavour and very few runners
‘Flamenco’ - fruits from May to November, very sweet with good disease resistance
‘Mara de Bois’ - strong flavour of wild fruit
Summer fruiting strawberries produce a lot of fruit over a period of 2 – 3 weeks so to get fruit all summer you need plants which fruit early, mid-season and late summer.
‘Honeoye’ - dark colour with a strong flavour
‘Alice’ - good disease resistance
‘Cambridge Favourite’ - popular heavy cropping variety
‘Florence’ - good flavour and good disease resistance
‘Symphony’ - good flavour
Wild or Alpine strawberries (Fragaria vesca) are tiny with an intense flavour. Their natural habitat is in hedge bottoms and the edge of woods. They are very easy to grow and self-seed freely, which can be a problem if you are a tidy gardener as they pop up all over the place. Sow the seed from January to April on the surface of good quality seed compost. Cover with a thin layer of Vermiculite as a little light aids germination. Put the tray into a tray of water for 10 – 15 minutes until the compost is damp. Put in a propagator at a temperature of 15 – 21C (59 – 68F) until they have germinated which should take 14 – 21 days. When the seedlings are large enough to handle prick out into 9cm (3”) pots using potting-on compost. Keep cool and plant out into the same conditions as the large strawberries when all danger of frost has passed.
Try this cheesecake recipe, I‘ve made it loads of times and it is really easy and delicious.
250g crushed digestive biscuits
100g melted butter
1 vanilla pod or a teasp. vanilla extract
600g full fat soft cheese
100g icing sugar
284ml pot double cream
25g icing sugar
Combine the crushed biscuits and melted butter. Press into the base of a loose bottomed 23cm tin which has been buttered and lined with parchment paper.
Roughly crush 100g of the strawberries with a fork and place over the base.
Beat together the soft cheese, vanilla pod seeds or extract and 100g of the icing sugar. Combine with the whipped double cream.
Pour into the tin and smooth the top.
Place in the fridge overnight to set.
Take out of the fridge 30 minutes before serving.
Stand on a can or bowl and gently slide down the outside of the tin. Place on a serving plate and slide off the tin bottom and parchment.
Puree together 200g strawberries, 25g icing sugar and a tbsp. water.
Arrange the remaining 200g strawberries in the centre and pour over the puree.
For more advice on growing fruit try the blog articles: ‘How to plant up a strawberry hanging basket’, ‘How to grow fruit in small spaces and containers on a limited budget’ and ‘How to grow your own 5-a-day'.