Growing Rhododendrons from seed

The first part of the process is to obtain fresh seed from one of the seed exchanges run by the rhododendron groups. Willie Campbell has been Seed Exchange Manager for the Scottish Rhododendron Society (SRS) since 2008. It involves annually creating a listing of seeds received from donors across the country and Europe.

There has been many changes in the last few years. Since 2013 the SRS have complied with the NAGOYA protocol, which in essence does not allow us to accept and distribute “Wild Collected” seed from what we called “Plant Hunting Expeditions”. For many years we had seed collected by Alan Clark, Keith Rushford and latterly in 2012 Willie Campbell made a trip to Sichuan, collecting seed for the seed exchange. All these collections of seed were annotated with collection numbers, e.g. AC (Alan Clark), KR (Keith Rushford) and CNC (Cox, Newton and Campbell).

Hand pollinated seed donations have dropped off. Once Peter Cox and Alan Anderson would contribute maybe 50 lots of seed. In recent years we have had increasing numbers of Open Pollinated seed donated, carefully sourced from species rich gardens. We always say that a few of the seedlings may not be the same as the true species. However, I have grown seed “wild collected” and sometimes in a batch of seedlings you get variation in the plants or just slight differences.

Peat Statement

We have suggested peat as a growing medium because it is a tried and tested method that will produce good results. However, we all have a responsibility to find sustainable alternatives and it is worth experimenting with other types of compost. Some suggestions are highlighted in our peat survey.

Next spring or a year since the seed was sown, you should have a decent plant and it’s now time to consider how you are going to grow on until planting out in the garden, woodlands or taking to your friends.

I used to in my Pro gardening days, line out the plants in raised beds of compost rich leaf mould I made on the estate each year, sometimes if it was too sunny, I would cover with mesh or fleece, watering when dry and so on. Make sure you label !

Most of us don’t have that space, and if you are like me have a succession of plants coming along, I pot up and label each plant and that’s the time to look at what you need for yourself or share with others or bring along to your local plant stall.

One tip I will always give at the start of each May is to pinch out the growing tips to make sure the plants do not become leggy and make a bushy plant. After 3 to 4 years you will have a plant ready to plant in the garden. I do hope that helps you grow rhododendrons from seed, it’s easy, quick and exciting.

By Willie Campbell

SRS propagation workshop. Filmed and edited by John Roy