Why Grow Raspberries in Pots?

Raspberries are a quintessential part of the British summer garden. While traditionally grown in sprawling rows in allotments or large kitchen gardens, they actually adapt wonderfully to container growing. For those with limited space, paved courtyards, or balconies, growing raspberry canes in planters is not only possible but can often yield a bumper crop due to the warmer soil temperatures found in pots.

The key to success lies in choosing the right variety, providing adequate support, and maintaining a consistent watering regime. Whether you are aiming for a summer berry pavlova or an autumn jam, here is how to cultivate these delicious fruits in the British climate.

Choosing Your Variety: Summer vs. Autumn

Before buying your canes, it is vital to understand the two main types of raspberries, as they require different care and fruit at different times.

• Summer-fruiting (Floricane): These produce fruit on year-old wood (canes that grew the previous summer). They generally crop heavily for a short period in June and July. Because the canes can grow quite tall, they almost always require structural support.
• Autumn-fruiting (Primocane): These produce fruit on the current season's growth. They provide a steady supply of berries from August until the first frosts in October or November. These are generally shorter and more self-supporting, though they still benefit from a trellis in windy UK weather.

The Right Planter and Location

Raspberries have shallow but spreading root systems and hate sitting in waterlogged soil. However, they also despise drying out. Therefore, size and drainage are critical.

You should aim for a container that is at least 45cm to 60cm wide and equally deep. Rectangular troughs are often better than round pots as they allow you to plant a row of canes, mimicking their natural growth habit.

Because raspberry canes—particularly summer varieties—can grow tall and unruly, they need vertical support to prevent the wind from snapping them or the heavy fruit from dragging them into the mud. On a patio, this often means pushing a pot against a wall or installing wires.

A convenient and stylish alternative is to use an integrated growing system. Our up to 2m long trellis planter with 1.8m high trellis is an ideal patio growing option. The substantial depth encourages healthy root growth, while the tall trellis provides the essential framework to tie in your canes as they grow. Available in natural wood, or painted black or grey, it blends seamlessly into modern or traditional garden aesthetics while solving the support issue instantly.

Position your planter in a sheltered, sunny spot. While raspberries can tolerate partial shade, the British sun is necessary to ripen the fruit and sweeten the flavour.

Planting Your Canes

The best time to plant bare-root canes is during the dormant season, between November and March. If you are buying potted plants from a garden centre, these can be planted at any time during the growing season.

1. Compost Mix: Use a loam-based compost like John Innes No. 3. This holds moisture and nutrients better than multi-purpose compost. Mix in about 20% grit to ensure sharp drainage.
2. Spacing: In a trough or long planter, space the canes about 45cm to 60cm apart. Do not overcrowd them, as good airflow is essential to prevent fungal diseases like grey mould (Botrytis), which is common in damp British summers.
3. Planting Depth: Plant the canes so the roots are just covered by about 5cm to 8cm of soil. If you plant them too deeply, the new shoots may struggle to emerge.
4. Initial Prune: If planting bare-root canes, cut the old cane down to about 25cm above the soil level immediately after planting.

Ongoing Care and Maintenance

Watering: This is the most critical factor for pot-grown raspberries. Containers dry out much faster than the ground. During dry spells in spring and summer, check the compost daily. The aim is moist, not sodden, soil. Irregular watering can lead to smaller, crumbly fruit.

Feeding: Raspberries are hungry plants. Apply a general-purpose fertiliser like blood, fish, and bone in early spring (March). As soon as the first flowers appear, switch to a high-potash liquid feed (like tomato feed) once a week to encourage fruit production.

Timeline: When to Expect Flowers and Fruit

The flowering and fruiting timeline depends heavily on the variety you have chosen and the specific weather patterns of the year.

• Flowering:
  • Summer varieties typically flower in May and June.
  • Autumn varieties usually flower later, around July.
  • The flowers are small, white-green, and very attractive to bees, which are essential for pollination.
• Fruiting:
  • Summer varieties: Ready to harvest from late June to early August.
  • Autumn varieties: Ready to harvest from August through to October (or until the first hard frost).

Pruning: Keeping it Simple

Pruning is essential to keep your plants healthy and productive. The method differs by type:

For Autumn-Fruiting: These are the easiest. In late winter (February), simply cut all the canes down to the ground. New canes will grow in spring which will bear fruit later that year.

For Summer-Fruiting: These require a bit more attention. In autumn, cut down only the canes that produced fruit this year (they will look brown and woody). Leave the fresh, green canes that grew this year—these are the ones that will carry the fruit next summer. Tie these fresh canes into your trellis support structure to protect them over winter.

By utilising a sturdy planter with vertical support and following these simple steps, you can enjoy bowls of fresh, British-grown raspberries straight from your patio year after year.