April at RBG Edinburgh

April has been another action-packed month at RBGE and summer feels ever closer. The lights on the front display cold frames have officially been removed, weeding has become more of a priority, and weekly mowing is a must!

This month I was able to take a tour of the herbarium and library, in preparation for a research project on the genus Trillium. It was great to see some examples of plants in the herbarium collection, especially of material gathered on AGS trips.

I completed the vine weevil larvae inspection I started last month. The young Saxifrage plants I’ve repotted, will hopefully stand a much better chance in their fresh mix. The pricking out of seedlings that have grown big enough has been ongoing too – potting on genera such as Calceolaria, Draba, Celmisia, Silene, and more.

Scott, Senior Alpine Horticulturist, showed me how to take Junellia micrantha cuttings. We first tidied up the stems by removing as much of the dead leaves as possible. Using sterilised glass cutting boards and new razor blades we took a mix of younger and older growth as propagation material. The cut was made either side of a node where small root nodules had already formed in many places. They were then placed onto the surface of propagation trays. Two of these were filled with a sand/fine pumice mix and the other two with coarse pumice, to see if there would be differences in the rooting rate.

One of my jobs has been planting in some of the alpine display borders. With the warm weather we’ve been having, watering the potted plants collection and frames takes longer each week. To make sure everything gets a bit of boost, plants are fed using a Dosatron system whilst watering.

Part of the iris collection have been planted straight into sand. John, the Rock and Alpine Department Supervisor, has seen this working really well on his recent travels. The irises have also had Floranid permanent fertiliser sprinkled around them which will mean that they’ll get a decent feed each time they’re watered.

A bit different from tweezer work with diminutive alpines was a job of path laying using barrow-fulls of hardcore at the base of two new plunge frames in the revero house. Once completed these new sand plunges will give more space for the potted collections.

Currently, there is a Rhododendron exhibition in Inverleith House at RBGE and I really enjoyed admiring the plants on display. If you’re visiting the gardens before the 5^th June then do take a look. I definitely took many Rhododendron photos from around the garden in April too, including Rhododendrum niveum, which is classed as vulnerable in the wild.