29. Growing Proteas
Proteas are notoriously tricky to grow in the UK, especially in the rainy North West. In their native South Africa they grow wild in the fynbos regions of the country, but have very specific requirements which are hard to reproduce in the UK. There are also some proteaceae plants like the Waratah and Banksias growing in Australia, an even harder environment to reproduce. But I read an interesting James Wong article about growing proteas outdoors in the UK, and the success a plantsman called Robbie Blackhall-Miles has had growing them just across the estuary from us in the hills of North Wales. So I decided to give them a try.
The first step was to do my research about proteas, the proteoid root systems, their growing conditions and planting requirements. There are quite a few books on the subject, but the most useful practical information came from UK nursery sites supplying proteas, in particular Graham Blunt from Plantbase nurseries in Kent. His advice is to grow them in very poor, free draining soil in specialist air-pots, designed to optimise airflow to the roots. Proteas are intolerant of any phosphorus in the soil - it will kill them, so a very specific compost mix is required. And they need excellent drainage, as much sun as possible and free moving air around them.
The potting mix I use is a 10:1 mix of pure Irish Moss Peat and Perlite. This gives a very poor quality, well drained acid medium that suits their proteoid roots. The plants require very little in the way of feeding, but do need frequent watering in the summer. In spite of being very drought tolerant in the ground, if the pot dries out you will lose it. Ideally I would be using rainwater, but don’t have a butt set up yet. I do notice a big difference in the plants between my tap watering and when it rains; they definitely prefer the latter.
Proteas really dislike any root disturbance, which can be a problem if they are grown in pots and need to be potted on. The air-pots solve that problem as well: the side of the pot unwraps easily, leaving the whole root ball intact. The older and more developed the plant, the more soil tolerant it will be.
I acquired 14 proteaceae plants from a couple of nurseries in Cornwall to kick-start my collection: a mixture of leucadendrons (cone bush), leucospermums (pin cushion), proteas (sugar bush), telopeas (waratah) and banksia. It has not always been plain sailing. I lost two of the leucadendrons early on because the pot dried out in the greenhouse, and a leucospermum didn’t survive being transplanted into the air-pots. The rest have adapted well and after an initial settling in period, are looking very healthy. They will need to be pruned every year to keep the size compact and encourage flowering.
For winter the dome will be covered with a horticultural fleece ‘tent’, which should protect them from the worst of the cold but still allow some air to circulate. According to GB it is a combination of wet and cold roots that will kill them, rather than just the cold itself. I am crossing fingers that these provisions will be enough, and that I don’t lose any more of them. Watch this space !
UK Nurseries selling Proteacaea
Plantbase Nurseries, Kent / Sussex