A READER wants to know if blueberries and cranberries can be grown successfully in containers on a balcony where they will receive plenty of sun.
The answer is yes, definitely. A straight-sided container of at least 40 centimetres diameter, not one curving in at the top, is recommended.
All berry plants grown in containers prefer an acid soil. Most standard potting mixes, especially the cheaper brands, are neutral and I suggest using a premium mix for acid-loving plants, which include all the rhododendron family, including azaleas and daphne.
Blueberries and cranberries have small white flowers in spring with the fruiting berries in late summer, followed by beautiful autumn leaf colour.
It is important, as with all container-grown plants, to raise the pot off the ground with pot feet to prevent waterlogging and root rot. On the other hand, the potting mix must not be allowed to dry out, especially near fruiting time.
Container-grown plants prefer rainwater, ideally from a rainwater tank or even from an old 44-gallon drum used to catch rainwater.
FEED container plants with a regular monthly feed with a liquid fertiliser such as Neutrog Seamungus or Maxicrop Seaweed Plant Food, which are classified as certified organic.
Although self-pollinating it is always advisable to grow two or even three different berry varieties if you have the space.
One can never have enough blueberries for their highly nutritional value and they can be frozen for eating when out of season.
Pick the berries when the fruit is completely blue with a slight white surface bloom from midsummer to early autumn.
The crop will need to be protected by netting from birds; like us, they love the berries.
Strawberries don’t need special garden beds and are ideal for growing in containers of which they are not fussy about the potting mix standard, providing they are fed regularly. They don’t need a large container and the traditional terracotta strawberry pot with holes in the sides is perfect for small spaces.
If limited for garden space, then grow them in a hanging basket. The best basket liner is the multi-coloured foam carpet underlay with plastic on one side. Place the plastic on the inside of the basket with a few holes in the bottom for drainage. The colours blend in with the garden and birds will not pull it apart as they do with coconut liners. I have had baskets lined like this for more than seven years and they still look good.
I HATE to see beautiful rainwater from the gutters disappearing down stormwater pipes to end up in the lake.
I try and capture as much as possible to go either into our 2500-litre rainwater tank or directly on to the garden. To do this, I have disconnected the downpipe and the rainwater goes into a small sump.
From there it flows through a plastic, perforated agricultural pipe and diverts evenly on to the garden beds. As can be seen from the photo, it is very easy to carry out this conversion and the plants just love fresh unadulterated rainwater.
- Feed container plants with liquid plant food rather than pelletised.
- When feeding berry fruits during the main growing season (when they are in flower to fruiting time) be guided by the old adage of “weakly, weekly”, a weak solution once a week.
- Raspberries are gross feeders and will need more frequent applications of plant food.
- Cranberries fruit slightly later in autumn.
- There are new dwarf varieties of blackberries that are more compact than the usual spreading stems.
- Thornless raspberries are becoming popular.
- Bamboo canes will be needed for raspberries and blackberries to make a frame to support the stems.