First half of apprenticeship year comes to an end

This year the AGS traineeship specialising in alpines is in two parts. My first placement at RHS Harlow Carr is coming to a close and the second placement at the Royal Botanic Gardens, Edinburgh is fast approaching.

I would like to offer a huge thank you to all the team at Harlow Carr, especially Amy, Aaron, and Aimee for supporting me during my alpine gardening traineeship. They have been amazing people to work with day-to-day. All of them have immense knowledge and passion for what they do.

Here are some of the things that I have been doing in January and February.

Indoor jobs

The collection of Petrocosmea was re-potted and the plants are now looking all the better for this. They are now in a new, more free-draining mix (as described in my previous post) and also they are now in shallower plastic pots rather than terracotta which means they will be less likely to dry out. When the time comes for them to be plunged into sand beds for public display, they will need to be replanted into terracotta pots.

The Pleiones need attention at this time of year, to remove any old hollow bulbils, and replace all of their moss top-dressing. I was surprised to see buds ready to burst into flower on some of them. We also completed repotting and feeding of the Calanthes and also removing all the old Hepatica leaves from the potted collection.

The Primula auricula and Primula marginata collections have had ongoing issues with root aphid and mealybug. To address this, the plants were initially stripped of all their previous compost and then cleaned in lukewarm water. They were then treated with insecticide and potted into fresh, new compost mix in sterilized terracotta pots.

Other winter jobs such as tidying up and picking over the collections have been ongoing. This ensures the plants are fresh and tidy as we come up to spring. Botrytis is a constant problem we have to keep watching for during winter, especially on the cushion plants. When we find damaged plants, we gently remove the affected piece with tweezers and treat the area with a small puff of sulphur.

Rejuvenating the Alpine House

The Alpine House was built and landscaped in 2009 and some of the plants were starting to look tired. The process of refreshing the landscaped beds in the Alpine House will take several years and I’ve been helping with a complete invigoration of one of the beds. The area chosen for this winter’s treatment firstly had its top dressing removed and saved into buckets to reuse after planting. We then removed the plants one by one and put them into crates so they could be looked after behind the scenes. The next stage was to move the bigger rocks and then remove all the old compost. At the bottom of the bed there was a thick membrane and a layer of old chopped up tyres. These had to be disposed of and replaced with large sandstone rubble for the base layer. On top of this successive layers of our own alpine mix and smaller rubble were added. We have started planting and were able to re-site a mature Lithodraba that was previously in the bed.

Sowing seeds

We recently received seeds from the AGS and SRGC seed exchanges and I have helped with sowing these. I greatly enjoyed this and found there is something very therapeutic about seed sowing. I thoroughly recommend growing plants from seed. There is nothing quite as satisfying as seeing them develop into fully grown plants. The AGS and SRGC offer a fantastic range of alpine and other seeds through their seed exchanges each year.

The method of sowing used by the team at Harlow Carr is as follows. Seed is mainly sown in small square pots and small seed trays are used for finer seed in higher quantities. A label is written with the full botanical name, date, and the source of the seed.

The container is mounded with the alpine mix compost and any excess is struck off in a sawing motion. Any large pieces are removed from the mix at this stage. We use a display plant label to press the surface lightly to ensure a flat sowing area. Seeds are then sown evenly on the surface. If seeds are big enough to handle with tweezers then they can be moved if they are too close together. Seed from the Campanulaceae family are left uncovered but the rest are covered with a fine layer of grit or chick flint. The pots and trays are then placed in a tray filled with water so they can soak it up from beneath.

Outdoor jobs

Outdoors, a new border was cultivated and planted up next to the Alpine House to showcase many different varieties of Galanthus from the collection. This border is at eye level so people can appreciate the delicate snowdrop blooms close up. Aaron, who is quite a galanthophile, laid out the snowdrops in groups. Each plant is easily distinguishable from its neighbour either by height, size of blooms, markings on flowers, etc. All varieties are planted in their own hidden aquatic basket which prevents bulbs getting mixed up.

Weeding and cutting back along the Streamside borders with Aimee is always a treat. There is a childish pleasure working in water and clambering over rocks whilst caring for a cool selection of plants. I’ve also been filling gaps in the large rocks along the streamside using Polypodiums. These were planted with the help of smaller rocks, clay, and compost. It is a very satisfying job trying to achieve a naturalistic look so the evergreen ferns can establish in these tricky areas. We hope this will also help prevent erosion. Another enjoyable fern job I did for Aimee was dividing patches of Blechnum chilense. This fern loves the wet and is also evergreen. Propagating these is important so we can use them in other areas of the stream, especially where rainfall naturally creates channels down some of the borders. The challenge was to divide the existing clumps of Blechnum whilst leaving the established ferns looking as though none had been taken. A few crates and pots were filled and taken to the nursery. They were then potted up to give the plants time to establish a good root system and bulk up before being returned to the garden.

Finally, I would like to mention two alpine plants from the collection that have recently caught my attention. The first is Saxifraga ‘Louis Armstrong’ which has vibrant pink-red flowers on a tight cushion. The other plant to make a big impression was Eranthis pinnatifida. This has hypnotic blue stamens standing out marvellously against its white petals.