Can Strawberries Be Grown In A Window Box?

Where on the balcony picturesque flowers, decorative leaves and bright red fruits captivate the viewer, strawberries do the honors in the window box. In fact, the tempting fruit plants are not limited to growing in the flower bed. This guide will familiarize you with everything you need to do to turn your balcony into a strawberry land of milk and honey. From the right location to the perfect balcony box to proper care, you’ll learn all the important details. A hand-picked list of ideal varieties will show you the way to your personal strawberry snack garden on the balcony.

Cultivation instructions

Successful cultivation of strawberries in the flowers is based on an interaction of important individual factors. Therefore, please pay attention to all sections of this guide, because sometimes it is only small things that cause the hoped-for harvest to fail.

Growing by sowing

Instead of purchasing ready-grown strawberry plants, cultivation for the ambitious home gardener begins with the seed. Certified seeds are available from specialist retailers. Alternatively, you can harvest the fine seeds yourself. For this purpose, dry fully ripe fruit and collect the seed nutlets from the outer skin. Store the seeds in a dark, cool and dry place until the sowing date in February or March. Here’s how to grow your own strawberries for the window box:

• Soak seeds in chamomile tea or lukewarm water for 4 to 6 hours.
• Fill a seed tray with growing soil and sprinkle with soft water
• Scatter the seeds, press them with a board and sift them thinly.
• Cover the seed tray with a transparent lid or cling film.
• In a semi-shaded window spot, germination takes between 2 and 6 weeks at an ideal 16 to 20 degrees Celsius. If the substrate dries out, spray it with room-warm water. At the 5-leaf stage, you can prick out the seedlings into individual pots. Until planting time begins, care is limited to regular watering during dry spells.

Tips for the perfect flower box

For vital growth and abundant harvest, strawberries in the window box need a sufficient volume of substrate. As a rule of thumb, it has been proven in practice to provide each plant with 25 to 30 cubic centimeters of soil. Therefore, choose flower boxes with a width of 25 to 30 cm. The length can be adjusted to the space available on the balcony. With 60, 90 or 120 cm long balcony boxes, any garden center is well stocked.

When purchasing, please make sure that a flower box has several bottom openings, so that excess rain and watering water can run off here. Rounded edges prevent the tendrils of your strawberry plants from snapping off. Planting boxes with an integrated irrigation system are advantageous. Here there is a water supply in a separate level, from which your thirsty plants can help themselves. The water level indicator shows when the supply needs to be replenished.

Tip: Balcony boxes in dark colors attract the sun, whereupon the substrate with the root balls can heat up strongly in midsummer. Therefore, the better choice are planter boxes in white or light pastel shades, because here the sun’s rays are reflected.

Substrate – mix it yourself is the trump card

Growing your own strawberries in a flower box offers not least the advantage that later you will know exactly what the fruit contains and what does not. Pre-fertilized potting soil from the discount store destroys this privilege. By mixing potting soil for your strawberries yourself, you pave the way to a premium quality strawberry harvest. Here’s how:

• Use organic vegetable soil without peat as a base.
• Mix mature, sieved compost into the organic substrate in a ratio of 1 : 3
• Add about 100 grams of horn shavings per window box
• A few handfuls of perlite, expanded clay or lava granules for optimized permeability

If you do not have your own compost pile available, you can find pre-packaged products in stores. Alternatively, add an organic slow-release fertilizer for berry plants to the substrate, such as the innovative
Organic fertilizer with sheep’s wool from Compo. The nutrients get growth and flowering going right from the start. A single addition is usually sufficient for the entire season.

Plant

Expert planting technique is based on important aspects, such as correct planting depth, appropriate planting distance, as well as preventing water from accumulating in the substrate. When the first warm rays of sunshine beckon in early April, the planting season for strawberries on the balcony begins. Here’s how to proceed correctly:

• Place the plants, still potted, in water to soak the root ball.
• Spread a layer of expanded clay, gravel, or shards of clay on the bottom of the box to provide drainage
• Place a breathable fleece over it to prevent the water-bearing layer from silting up
• Fill in the substrate so that a watering rim is exposed
• Pot out the strawberries and plant them at a distance of 20 to 30 cm from each other

It is important to note that you measure the planting depth so that the heart bud is just above the soil surface. Press the substrate firmly with both hands for a good soil seal. Carry the finished planted strawberry box to its location first and then water.

Tip: To allow the loose substrate mixture to settle, add it to the balcony box about 2 to 3 weeks before planting. This precaution prevents the root balls of freshly planted Strawberries

Location

A sunny, warm and airy position in the south-exposed location will give you a strawberry harvest of the best quality on the balcony. In a semi-shaded place, the frugal plants also thrive. However, the abundance of flowers and fruit regularly leave much to be desired.

Watering and fertilizing

One of the key features of care is a steady supply of water. On hot summer days, check early in the morning and again in the evening to see if the soil has dried out. Let the water from the watering can run directly onto the substrate until it runs out of the soil holes. The next time watering is done only when the surface of the soil has dried noticeably. Field tests in professional cultivation of strawberries have proved that the best time for watering is in the early morning between 3 and 4 o’clock.

If you don’t like to get up that early, take care of your strawberry plants on the balcony in time before the sun hits the leaves directly. If you follow our recommendation for a nutritious substrate mixture, further gifts of fertilizer are not necessary in the first year. Only when the leaves turn light green to yellowish and indicate a lack of nutrients, administer a liquid organic fertilizer for berry plants. In subsequent years, provide strawberry plants on the balcony with an organic plant fertilizer added to the watering every 3 to 4 weeks from April to September.

Mulching keeps strawberries clean and healthy

In the window box, strawberries rarely come into contact with the substrate. Rather, the long tendrils dangle elegantly over the edge. Where fruit and soil do come into contact, lay down a layer of straw mulch. This simple trick keeps strawberries clean and protects them from rot and mold.

Pruning after harvest

Depending on your choice of variety, harvesting extends into October. When the strawberry season on the balcony is over, cut back the plants. To do this, remove all leaves and tendrils except for the heart bud. With this pruning, you eliminate accumulated inhibitors that could interfere with another strawberry season on the balcony.

Wintering – Tips & Tricks

Strawberry plants are hardy, so they will thrive in the window box for several years. Experience has shown that they retain their vigor for at least two to three years before becoming depleted by the fourth year. Since the root balls are in a vulnerable position behind the thin walls of the balcony box, we recommend this winter protection:

• After pruning, place the flower box in a niche protected from wind and rain
• Place a wooden or polystyrene base under the box
• Wrap the container with bubble wrap
• Pull a coconut mat over the foil, overhanging the edge of the box by 10 cm
• Cover the substrate with leaves, wood wool or straw

If winter damage occurs to strawberries in the window box, drought stress is the most common cause. Therefore, keep watering the plants so that the soil does not dry out.

Ideal varieties – a selection for the balcony

Forest strawberries and varieties derived from them are perfectly suited for cultivation in the flower box. Unlike the majestic garden strawberries, they remain small and compact to give us countless juicy sweet fruits. As a special benefit, balcony gardeners appreciate that the following varieties fruit several times for a never-ending harvest season into the fall:

Ostara

This strawberry is one of the leading varieties for growing in window boxes. Its large, red fruits are suitable for both fresh eating and freezing. By pruning out the first two or three flower stalks in spring, you increase the yield. Thanks to its numerous runners, Ostara offers plenty of material for vegetative propagation each fall.
Height of growth: 30 to 40 cm

Mara de Bois

This everbearing strawberry variety from France delights with medium-sized, aromatic fruits. The cone-shaped fruits with their soft flesh are excellent for snacking and for making jam. Home gardeners appreciate that this strawberry plant does not form runners, which reduces maintenance and pruning requirements.

Amandine

This new variety attracts attention with elongated red fruits that invite snacking. In addition, Amandine proves to be well resistant to fungal diseases. Thanks to its soft consistency, housewives like to use this variety for canning.

Toscana

With beautiful pink flowers, this strawberry plant is a feast for the eyes on the balcony. From July to October, Toscana offers fruity-sweet treats that taste best fresh off the stem. In a sunny location and cultivated according to these instructions, you can look forward to a crop yield of up to 1 kg per plant.

Sperling’s Bowl Magic

The variety name reveals that this variety is ideal for a tangy fruit treat. This is not contradicted by the fact that the sugary, small strawberries end up directly in the mouths of young and old or shine as a tempting cake topping. As a typical monthly strawberry, the variety blooms and fruits throughout the summer and does without annoying runners.

Mignonette

Try this tempting fancier variety for growing in a window box. This everbearing wild strawberry can be snacked on from the comfort of your lawn chair all summer long. Its bushy habit and an enchanting white-pink bloom add decorative accents on the balcony at the same time.
Height and length of growth: 15 to 20 cm.

Forest Queen

The true wild strawberry has proven itself as a classic for cultivation in the balcony box and in the bed. White flowers, healthy leaves and compact growth characterize this premium variety. The small red fruits with the sugary sweet aroma also find a place in the small mouths of children.

White Fairy

The creamy white fruits with yellowish nutlets immediately catch the eye and harmonize wonderfully with the green leaves and white flowers. This particular variety comes from the Hummi range, which produces strawberries with a pineapple aroma. Moreover, White Fairy is not necessarily dependent on a full sun location, because in partial shade it also thrives lush and flowery.

Plena

The ideal variety for gardeners who attach more importance to decorative value than to crop yield. The monthly strawberry dresses itself from May to July in a garment of white, profusely double flowers, from which only a few fruits develop. Known historical variety is a perfect candidate for the authentic planting plan in the cottage garden. Thanks to a growth height of 15 to 20 cm, it feels at home not only in the bed, but also in the large window box.

Rimona

The ideal balcony strawberry from the traditional company Ahrens and Siebertz rounds off the hand-picked list of varieties. As a monthly strawberry, Rimona has everything we want from a strawberry for growing in a window box. Compact growth, enchanting flowers, healthy foliage, and droves of juicy, aromatic fruit from spring through fall.

Conclusion

With these instructions, the dream of strawberry snack garden on the balcony is within reach. A large, 25 to 30 cm wide flower box in a sunny, warm location provides the tempting plants with ideal conditions for vigorous, high-yield growth. A mixture of organic vegetable soil, compost and horn shavings or natural slow-release fertilizer guarantees healthy strawberries for the whole family. Care is limited to watering during dry spells, which may be necessary in the morning and evening hours in mid-summer. Follow our recommendations for ideal varieties, harvest juicy sweet fruit pralines into the fall. Pruning down to the heart bud, as well as a thick winter coat for the balcony box will ensure that strawberry plants survive the cold season unscathed.