How to grow alpine plants from seed

Why grow from seed?

These are just a few reasons to choose seed over ready-to-plant alpines:

• The average packet of seed will produce many plants.
• You can increase your chances of success by planting them in different parts of the garden.
• If you know other keen gardeners, you can swap the surplus with them and expand your range of plants.
• Many alpines vary from seed. Size, flower colour and abundance are just some variants.
• Many rare plants are only available as seed.
• As an AGS member, you can join our annual Seed Exchange. This grants you access to more than 5,000 different kinds of seed.

How to choose your seed

Start by researching the plants you’d like to grow. (Our factfiles are a good introduction to alpine plants.) Make a note of those you like. This is especially useful if you struggle to remember the Latin names. Our encyclopaedia contains much more detailed information about alpine plants for those who wish to learn more.

Getting your seed from specialist alpine societies, like the AGS, is a great way to ensure quality. Find out more about our Seed Exchange here.

When to sow

Usually, you can sow your seeds straight away. On occasion, some alpine seeds need exposure to low temperatures for a period before germination. (An average UK winter should provide the right temperatures.)

Sowing seed later in the year could delay germination until the following winter or spring.

Nurturing your seeds

From compost to pots, here’s what you need to support your alpine seed:

Compost

Most alpines suit a compost made from three parts John Innes Compost No 1 (by volume) and one part concreting sand. (Concreting sand is also known as grit or coarse sand.)

For ericaceous plants (e.g. Rhododendron, Cassiope), woodland plants and those which need an acidic compost (e.g. Trillium, many Primulas), a commercial ericaceous compost is suitable. You could also use fine-grade composted bark.

Most alpines are tough and adaptable so the precise compost composition is less important than how well it drains when watered.

Pots

The type of pot is unimportant but many growers opt for 7 or 9cm square plastic pots. Square pots fit together neatly, and make watering easier.

How to pot

• Fill your pot loosely to the top then press it down gently.
• Test your compost mix by filling a pot with water. (Note: if the water doesn’t drain quickly, you need better drainage. Add more grit or coarse sand.)
• Label your plants. Note the plant name, source of seed and date of sowing. (If seeds are large, you could also add the number of seeds.)

When all of the seed is sown, the pots are best watered by standing in a tray of water to about half of their depth, until the surface of the grit or compost becomes moist.

Where to grow

Alpine seeds respond best to cold weather, not a frost-free greenhouse. A north-facing position is ideal. A cold frame, pane of glass or plastic sheet over the pots will protect the seed from being washed away by heavy rain, but don’t let the pots dry out.

Maintenance

Check on your pots once a week for the first germinations.

When germination occurs, it’s a good idea to put down slug bait. Slugs and snails love to snack on young alpine seedlings!

Potting on

Pots of young seedlings can be moved to a sunnier spot and given an occasional liquid feed to encourage progress.

Many experienced growers leave bulb seedlings in their original pots for two years. For faster-growing plants, try transplanting them at the two seed-leaf stage, or as the first true leaf develops.

Most alpines grow very long roots. If left to grow too long, they can become tangled and more prone to damage when you come to transplant them.

After transplanting, water your seedlings by standing the pots on a few cm of water. Place them in a shaded spot until they begin to grow again.

Remember…

Keep these basic steps in mind you’re set to enjoy success when growing alpine plants from seed…

• Choose your seed
• Sow it
• Germinate
• Pot on
• Grow on
• Plant out
• And most importantly, enjoy!