Grow Blueberries in Containers

WHICH VARIETY OF BLUEBERRIES SHOULD I PLANT?

You don't have to have a yard, ideal soil, or perfect drainage to raise Blueberries in an apartment - you need a sunny location and enough room for a container. Transform a deck, terrace, patio, or Balcony into an orchard of Blueberries.

When choosing blueberry plants, be aware that some need a "friend". For them to produce fruit, at least two plants of two different varieties are required for cross-pollination. I prefer self-pollinating dwarf varieties such as Blueberry Burst and Blueberry Kisses. If you want Blueberries all through the season, you can select types that produce fruit at different times of the growing season to extend your blueberry harvests.

It's essential to choose a blueberry species and cultivar that's right for your climate and situation. Your local nursery will be able to help you with this. Container grown Blueberries live happily for years when given what they need, and I'll go through the essential points below.

Be mindful of your Grow Zone before selecting your Blueberry shrub

Be aware of the conditions in your small space and choose a variety that will enjoy those conditions and thrive. For more information, you can refer to the internet and my Blog, Know Your Grow Zone. 

Three main types of Blueberries suit the Australian climate - Northern Highbush, Southern high bush and Rabbiteye, with many cultivars available within these categories. Your nursery will be able to assist you with the best choice for your small space.

PREPARE YOUR POTTING MIX

The soil mix with the right amount of pH is critical to success - soil is everything! Soil with a pH in the 4.0 - 5.0 range is essential for the plants to absorb water and nutrients and produce berries.

If you're not at the stage of mixing your potting, mix a good quality potting mix designed for acid-loving plants (such as rhododendrons, azaleas, and camellias). You can find these types of blends at the garden centre.

Some recipes for an appropriate acidic potting mix include:

• Good-quality peat moss (40%) mixed with the smallest size of pine bark mulch (60%). This mixture creates light, loamy and acidic soil that holds some water but allows good airflow to keep roots healthy.
• Equal parts peat moss and vermiculite, then add in a granular fertiliser. Test the mixture's pH level using a soil test kit, and adjust the pH level if necessary by adding limestone to raise the pH or iron sulphate to lower the pH. (Cornell University)
• An equally effective potting mix uses equal parts garden soil, well-rotted compost, and coarse sand. Test the mixture's pH balance and add iron sulphate as needed to increase acidity. (Cornell University) 

How do you lower the pH of your soil?

Add organic matter – You can add organic matter to your soil annually for a gradual pH-lowering effect – peat is an excellent choice.

Add aluminium sulphate – it creates acidity in the soil instantly as soon as it dissolves. Find it at your local garden centre or hardware supplier

Add sulphur – this is cheaper than aluminium sulphate but is also slower to act

SELECT YOUR POT

Blueberries have a shallow fibrous root system, which needs space to grow and absorb nutrients. So while a fairly wide pot is required, it does not have to be extremely deep. A new small shrub can be planted into a container of around 30cm wide for the first 2 or 3 years, and when it grows out of that, a 40 -50cm diameter container can be its permanent home. 

As the bush might grow to about 1m in height and 70cm across at maturity, a large ceramic style pot will be weighty to relocate. Blueberry shrubs are cultivated in Root Pouch grow bags are perfect for small spaces where changing conditions of sunlight, wind, and rain may require the pot to be moved through the year. Planting them in Root Pouch grow bags means root circling will not happen, giving longevity in their existing pot.

Blueberry plants need a lot of water, but they also like well-draining soil. In other words, they don't want to be sitting in water. Root Pouch grow bags are free-draining, so you will never have this issue growing in them.

You have purchased one of these fantastic Grow Kits that provide you with a Waterpot Olla to ensure consistent hydration at the root level.

 

HOW TO PLANT YOUR BLUEBERRY SHRUB

Plant your Blueberry shrubs into their new grow bags or containers, burying them as deep as they were in their nursery pots. Make sure you don't plant the bush any deeper than it grew in the pot, or it may end up with collar rot (that bit on the trunk that was at soil level). If necessary, top with additional soil, leaving the top couple of centimetres lower than the top of the bag or container. Immediately water the pot thoroughly to settle the soil and eliminate any air gaps around the plant's roots.

When using one of our fabulous Waterpot Ollas, place the Olla to the side of the centre (plant will sit in the centre) without touching the side of the bag and pack the soil around the Olla to the shoulders.

WATERING

Blueberry plants need a lot of water, but they also like well-drained, so keep the soil consistently moist but not soggy. Unfortunately, they are not drought-tolerant and will stop producing flowers and fruit if left to dry out.

Keeping your Waterpot Olla topped up, you can be assured that the shrub will be delivered water to the roots where it is needed, economically (you'll save water!) and when it requires a drink! 

Water in your shrub well and keep surface watering going for two weeks whilst keeping your Olla filled and checked regularly to see if topping up is necessary. Eventually, the Olla will take over the watering. However, the water demand is greatest from fruit expansion until harvest, so DO remember to keep your Olla full. When it rains, allow your shrub to enjoy the shower and infusion of minerals from the natural rainwater.

If using other methods of irrigation as much as possible, try to keep water off the leaves.

Mulch with bark or my favourite Sugar Cane mulch, keeping the mulch away from the plant stem

 

 

 

PLACEMENT

Like most fruits, Blueberries do best when they have full sun all day. They can cope with a bit of shade, but if you want lots of Blueberries off your shrub, it will need to be situated in 6-8 hours of full sun. However, if you live in an area with a very hot afternoon sun, be aware that blueberry plants can overheat. Therefore, they likely will appreciate some light shade during this part of the day.

You may need to move your containers around during the day to ensure the plants get the required amount of sunshine. With big pots, putting the containers on rolling casters makes it easier to follow the sun. My shrubs live in the western side of the Balcony in the cooler months and are shifted to the eastern side during Summer. Root Pouch grow bags make light work of this, and the largest of my shrubs is on a trolley

FERTILISE 

Blueberries don't like too much fertiliser, and primarily if you have used a good quality potting mix, their nutritional needs will be well taken care of for the number of months stated on the bag of mix. After this time, use a good three-month slow-release fertiliser such as composted cow manure every three months and add a good liquid fertiliser every fortnight through the growing season.

For plants six months or older, applying half a teaspoon of Potassium Sulphate to the potting mix once a month throughout the year will improve fruit size. Superphosphate (half a teaspoon every six months) will strengthen root growth when the plant is fruiting. Foliar applications of a good seaweed solution every week from flowering will improve fruit size.

Test the soil's pH regularly to ensure it is between 4.0 and 5.0. Because acid washes out of the soil over time, you may find that it's more effective to start with a half dose of fertiliser in the spring and then add a light monthly dose throughout the growing season.

If this kind of science is not your thing, just pop into the garden centre and pick up a proprietary Azalea/Camelia fertiliser or a general fruit fertiliser that is suitable for acid loving plants.