30. The Protea Dome

The first geodesic dome will be used to house my collection of Proteaceae plants, all grown in pots. They are notoriously tricky to grow in the UK, especially in the rainy North West, so need specific conditions which I am hoping the dome will help to provide.

The first important requirement is good drainage. The dome floor is lawn covered by a permeable weed membrane, then a CEDAdrive stabilisation panel with gravel over the top. It will absorb any run-off or accumulation of water easily. The grey rubber edging serves two purposes: to contain the gravel and to allow for easy lawn mowing around the edge of the structure.

The second important requirement is the soil. Protea root systems need very poor, free draining acid soil without any phosphorus present, so I use a precisely mixed medium in specialist air-pots to optimise air flow and drainage for the plants. These air-pots also avoid any root disturbance when the proteas need to be planted on.

The third important requirement is protection from very cold weather and frost. While many proteas are hardy to -7 degrees, it is the combination of very low temperatures and wet roots that really seems to do the damage and kill them off. In the spring, summer and autumn months the dome will be left open to the elements, giving the plants as much sun and fresh air as possible. In the winter I will line the dome with a large tent made of a heavy duty horticultural fleece. It attaches to the dome structure using drawstrings, and can be zipped open to allow airflow to the plants. It can be removed and stored away in the spring when the weather improves.

This dome is in the sunniest part of the garden, so the plants get good light for most of the day, and the garden walls protect them from the worst of the winds. They have settled in well this season and are thriving. I am crossing fingers that their winter cover will be as effective in keeping them healthy.