I’ve germinated some lemon seeds but how do I overwinter the plants?
John Wilson, by email
Stefan says: It’s always satisfying when seeds from fruit germinate although, as you realise, most kinds originate in warm temperate or tropical climates so are not suitable for growing outdoors. You say you only want the plants as ornamentals and are not expecting any fruit, which is probably wise as I would be surprised if you produce any.
They should be kept somewhere frost-free, such as in a greenhouse, conservatory or on a windowsill. You may have seen the orangeries in great country houses where citrus trees were grown in large containers outdoors in the summer, and then wheeled inside for the winter. Don’t over water, but conversely, don’t allow them to become too dry. I find they always fare best in an ericaceous, acidic compost and ideally should be watered with soft rainwater.