Planting rare and hardy bulbs

What are the rare and hardy bulbs?

Rare and hardy bulbs add a unique touch to the garden while adapting to various climates. Among them, you’ll find the surprising Arisaema, with its cobra-shaped flowers, the Galtonia viridiflora (-10°C), with its pale green bells, and the Eucomis, or “pineapple plants”, which add an exotic touch. Let’s not forget the majestic Cardiocrinum giganteum (down to -15°C), or Giant Himalayan Lily, which impresses with its height and fragrant white flowers, while the Lycoris aurea or Lycoris radiata (down to -8°C), with their vibrant red or golden tones, add an Asian flair. We can also add to this list some uncommon orchids such as Cypripedium, Bletilla, Habenaria radiata, Calanthes and Pleiones.

As for Amarcrinums, Sprekelia formosissima and Scadoxus multiflorus, these bulbs are slightly more tender (hardy down to around -4°C in well-drained soil). They can only be grown in the ground in frost-free regions, such as the Mediterranean coast or the most sheltered areas of the Atlantic coastline.

Discover our advice sheet “7 rare and original bulbs” as well as our full range of rare bulbs.

Why grow them?

Growing rare and hardy bulbs is a way to introduce originality and diversity into your garden. These plants typically stand out for their spectacular or unusual blooms, sparking curiosity. They catch the eye and are sure to surprise your friends and family when you show them around your garden! Some, like Lycoris or Eucomis, boast strikingly exotic flowers. Their rarity makes them true treasures for botany enthusiasts, while their hardiness allows them to thrive in most gardens without needing winter protection! The fact that they are rare doesn’t necessarily mean they are difficult to grow. Lastly, choosing rare and hardy bulbs also helps preserve and promote lesser-cultivated species, contributing to biodiversity and enriching our gardens.

Where to plant rare and hardy bulbs?

Rare and hardy bulbs can be incorporated into many types of gardens, provided they are given a location suited to their specific needs. They generally prefer well-drained soils to avoid excess moisture, especially in winter. Slightly raised areas or rock gardens are ideal for many species sensitive to waterlogging.

For shade-loving plants such as Arisaema or Cypripedium, opt for sheltered beds away from direct sunlight, under trees or at the edge of woodland. On the other hand, Lycoris or Eucomis thrive best in sunny spots, where their blooms will be showcased.

Soil choice is crucial: it should be rich in humus, light, and moist with a slightly acidic to neutral pH. In summer, it should remain relatively cool but never waterlogged, as these bulbs are particularly vulnerable to excess moisture. If your soil is heavy or tends to stay too wet in winter, place the bulb directly on a drainage layer a few centimetres thick—ideally 5 cm of perlite, vermiculite, pumice, or gravel.

Whether planted in pots or directly in the ground, these bulbs also suit urban gardens or small spaces, offering flexible planting options. Just ensure you adapt the substrate and planting depth for each species to maximise their growth and flowering.

When to plant them?

The ideal time to plant rare and hardy bulbs mainly depends on their growth and flowering cycle. Generally, spring-flowering bulbs, such as Galtonia or certain Cypripedium, should be planted in autumn, before the first frosts, to allow them to establish roots during winter.

Summer or autumn-flowering species, like Lycoris or Eucomis, are typically planted in spring, once the risk of frost has passed. This ensures optimal growing conditions with milder temperatures.

For certain terrestrial orchids, such as Pleione or Bletilla, early spring or late autumn may also be suitable, depending on the specific recommendations for each species. Be sure to follow these planting times to ensure successful establishment and spectacular blooms.

How to plant them?

In the ground:

• Using a dibber or small trowel, dig a hole 5 to 10 cm deep, depending on the bulb size,
• Optionally add drainage materials at the bottom of the hole, such as gravel, pumice, vermiculite or perlite, to improve drainage.
• If your soil is too heavy or poor, mix the removed soil with one-third gravel, one-third compost and one-third peat
• Place the bulb in the planting hole, pointed end upwards.
• Cover with soil and lightly firm down.
• Water to help the bulb settle in.

In pots:

• Choose a terracotta pot, wider than it is tall, to promote good drainage.
• Fill the pot with substrate, ideally a mix of half perlite or vermiculite and half leaf mould.
• Plant the bulbs about 5 cm deep, spacing them to avoid touching.
• All that remains is to water.

Ensure the substrate remains slightly moist but never waterlogged. In winter, keep the pot frost-free in a cool, dry place and water very lightly (just a few drops every fortnight). Resume watering in spring as soon as the bulbs begin to sprout.

How to care for them?

During the growing period, regular but moderate watering is essential to avoid both drying out and excess moisture, which could cause the bulbs to rot. Once flowering has finished, gradually reduce watering to allow the foliage to wither naturally, enabling the bulb to replenish its reserves.

We recommend adding a little compost or organic fertiliser each year at the start of spring. For species grown in pots, it’s ideal to partially refresh the substrate every two or three years to maintain its richness and structure.

In winter, protect frost-sensitive bulbs with a thick mulch, such as straw or dead leaves. Some bulbs, like Lycoris or Pleione, require a dry dormant period: limit watering during winter, gradually resuming in spring when new shoots appear.

Finally, regularly check your bulbs for any pests or diseases. Slugs, aphids, or rot can sometimes cause problems, especially in damp conditions. Appropriate vigilance and a few preventive measures will ensure the good health of your plants.