Every year, in the second week of March, millions of shamrock plants are flown from Ireland to destinations around the globe in order to reach the lapels of the Diaspora in time for St Patrick’s Day on 17th March.

Although a traditional plant, modern technology has improved the shamrock’s shelf life dramatically so that the vegetation not only looks spry and bouncy on the day of celebration, but for several more days if kept in a fridge.

The secret lies in modern packaging. The shamrock plants are separated into small bushy clumps and their roots are protected in hydrogels. These are polymers that can hold several hundred times their own weight in water, ensuring the plant survives in its packaging for at least ten days.

Because these are packaged with ‘root intact’, they can also survive as a houseplant for a lot longer: 25 to 30 years longer! Compare that with the majority of shamrock plants which end up consigned to the bin before 18th March dawns.

Follow these simple instructions if you want to keep your little bit of Ireland thriving after the St Patrick’s Day celebrations are over.

• 1. Keep the shamrock in its hydrogel packaging in the fridge until you are ready to pot it, the sooner the better (not longer than 4 days).
• 2. Prepare a pot. Clean the pot, place broken crocks or clean stones at the bottom (to ensure drainage) and fill to one inch of the top with good quality all-purpose compost.
• 3. Carefully remove the shamrock, with its root still wrapped in hydrogel, from its packaging and transfer it to a clean, prepared pot. Water.
• 4. Keep the shamrock plant in a bright spot without direct sunlight and ensure its compost is kept moist. It will reward you with plush green leaves for most of the year.
• 5. After flowering, the its leaves will turn yellow and droopy. This is the shamrock plant’s way of telling you that it needs a rest. Remove all the dying leaves and cut back on water. It won’t be long before all the leaves and stems need to be removed.
• 6. Move the pot to a cool, dry and shady (not dark) location for two to three months. At the first sign of new growth, wake it up properly with a tiny bit of water and a sprinkling on the top of the compost of an all-purpose plant food, and return it to the light.
• 7. If you choose, you can place the pot outside in summer but choose a shady position. Make sure to bring it in as autumn arrives as the shamrock plant cannot tolerate frost.

Treated well, your shamrock plant should survive for years. Success rates depends to some extent on the species of the original shamrock sprig (contrary to popular opinion, there is not just one type of shamrock). If your sprig came direct from Ireland it is probably of the Trifolium Dubium variety while in the US, oxalis are often sold as shamrock plants.

The former can be a little more temperamental, and will take its annual sleep from July or August to October or November. Oxalis comes in many colours and typically prefers to rest between November and February.

What really matters is whether or not the sprig you wear on your lapel on St Patrick’s day is held in hydrogel ‘root intact’. If it is, your shamrock plant has a good chance of surviving as a cheery reminder of Ireland for many years.