Discovered by a Flemish botanist, rhododendrons were first introduced to the United Kingdom in the mid 17th century. They are celebrated for their bright and greatly varied colours, with some species often growing clusters of flowers.
Where and when to plant rhododendrons
- Plant them in autumn or spring
- Before you get underway, ensure you have dug in ample neutral or acidic organic matter
- Plant so that the roots are just submerged in the soil -don’t go any deeper
- Top with a good layer of mulch (around 8cm), and look to refresh this each spring
Can they grow in a pot?
Yes, most varieties will thrive in large pots. Just remember they will need watered and fed regularly, especially during the growing season. Aim to re-pot every second year.
When do rhododendrons bloom?
They flower in spring.
How often should they be fed, and with what?
Use an ericaceous fertiliser as Rhododendrons thrive in acid soil. Consider top dressing with peat as this will help keep the soil more acidic.
How often should they be watered?
They thrive in the wet! Ideally leave them to be watered by the rain. However, if this is not ample then switch to tap water, but bear in mind it is often too high in calcium for them to handle. As such, rely on the rain as often as possible.
How high will they grow?
They can become really quite substantial if left to grow untrained, reaching up to 6-foot high and in some cases beyond.
Do rhododendrons like shade?
Yes, they do like light and dappled shading.
You don’t really have to worry about this unless it’s required for your garden management. If you’ve time, then spend it deadheading rather than pruning. That said, they are not adverse to a hard cutting back, and will respond well.
When do you deadhead them?
Once the flowers are spent, you can deadhead them. Again, however, it’s not crucial as the plant will still bloom the following season.
Problems with rhododendrons
The most common problem occurs if weather is dry when the buds begin to form. If this happens, it could stunt formation resulting in them dropping unopened come spring.
Are rhododendrons poisonous to dogs and cats?
Yes! They are highly poisonous an can cause death even with just eating a small bit of leaf.