Planting in Containers

Rhododendrons and Azaleas can be grown very successfully in containers providing you are prepared to maintain them properly.

In some locations it may be the only way to grow these beautiful plants. We do not recommend planting the taller hybrids in pots nor our Plantsman range that may need a little more TLC. The most successful varieties are Compact and Dwarf Rhododendrons, and Evergreen and Deciduous Azaleas. Follow these tips and your plants should flourish.

• Firstly, pot selection - don’t choose a pot that is too much larger than the original. For example, if your plant is in a 3 litre pot now, then we recommend that you pot into a 7.5 litre (approx 9",23cm) pot. Rhododendrons will grow best in relatively small pots, which allows them to be potted on every 2-3 years with fresh compost into the next size up, allowing an extra 5-16cm around the edges. Squat pots (not too tall) are best – remember Rhododendrons are shallow rooted plants.
• Next, ensure that you use a good ericaceous compost. A little course bark or woodchips mixed with a good ericaceous compost will aid drainage. Ensure that there are plenty of drainage holes in your pot, and make sure the bottom of the compost does not become saturated in winter.
• Follow our tips on How to Plant a Rhododendron to ensure that you don’t plant too deeply.
• Now, the magic ingredient – water! Your plant will not survive for long if you allow the roots to dry out. Equally, if the compost is too soggy, the water can become stagnant and this could lead to poor growth and disease. So don’t stand the pot in water and ensure that you water regularly, especially during dry spells. A substantial drink is far better than a dribble. Rain-water is best, particularly in hard water areas, but tap water is better than no water!
• Feed – you wouldn’t survive long without food, and neither will your Rhododendron. The easiest way to provide essential nutrients is to use a slow release fertilizer (such as Miracle Gro Ericaceous Slow Release). Add a sprinkling to the top of the pot once a year in March. All the nutrients will be taken into the root of the plant over the course of the growing season. One feed a year with this type of fertilizer will suffice. Of course, you may wish to use a water soluble type feed, this is absolutely fine provided it is designed for ericaceous plants and you follow the instructions on the pack. Water soluble fertilizer should be used between March and mid August, but don’t be tempted to use beyond August as growth will continue at the expense of flower buds next year.
• Try to avoid planting other plants in the pot with your Rhododendrons. They will just be competing for moisture.
• Can I mulch? Absolutely, use bark chippings or pine needles. Avoid using pea shingle or stones, as these conduct heat and cold to the shallow roots of the plant.
• What about very cold weather? The foliage will tolerate much colder weather than the roots. (Camellias are especially vulnerable to root death in cold weather). During very cold spells, the foliage will often droop and look a little sorry for itself, but don’t worry it will perk up again once the temperatures warm up. We ‘bulk up’ our container plants during the winter (huddle them together to keep warm!). If the temperature is likely to drop below –10oC then cover them with fleece or better still dig the container into the ground or transfer them to a cold greenhouse.