Taking care of tender plants

Plants don’t do particularly well in the cold and harsh conditions of winter. Tender plants in particular will be killed off by frost if they’re left exposed to the elements, so that extra protection they get from being brought inside is crucial. You’re not looking for growth (plants go dormant during winter) but the shelter will keep them alive and help them come back strongly in the spring. Even if your greenhouse isn’t heated, it can still keep overnight temperatures as much as 5°C warmer than outside which is enough to keep the frost out.

Some of the plants that are suitable to be moved are tender herbaceous perennials like dahlias, cannas and begonias. What groups these together is that they all have fleshy tubers, rhizomes or corms that can survive in a dormant state when they’re lifted and stored somewhere else. Find a frost-free location in full sun such as a greenhouse - bonus points if it’s heated. If you don’t have a greenhouse, a conservatory or even a south-facing windowsill will suffice. Your plants will go dormant over the winter period, so water them sparingly and allow the compost to dry out between watering.

If you have some tender plants in the ground that are too big to lift and store somewhere else, you can use a thick, dry mulch to protect them instead. You can use all sorts of different materials for mulching - everything from garden compost and well-rotted manure to straw and chipped bark. Plants like cannas and dahlias can be overwintered with mulch in milder areas and sheltered, well-drained parts of the garden. Just cut back the tops of tender plants, leave them in the ground and cover them with a thick mulch. Just be aware that plants protected under mulch might come into growth and flower a bit later than those that were lifted, stored inside and replanted in spring.

An alternative way to protect tender plants that can’t be lifted is to wrap them up. You can use materials such as fleece, hessian, bracken, straw and even bubblewrap to insulate your plants from the cold. If there are extended periods of very mild weather forecast, remove any wrapping to prevent sweating and possible rotting. Then replace the covers if the cold moves back in. Before wrapping, make sure you remove any damp debris from the base of the plant. Pack the crown with a good amount of dry material like straw or dry bracken, and use a waterproof material to cover the plant.