Hartley Magazine

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It is becoming hard to ignore the fact that my tender plants need to go back inside the greenhouse. It has been a mild autumn so far, and the temptation to leave them outside is huge. They look so nice, and are still mixed up with the houseplants too, which have been outside for a summer refresh and to put on a bit of growth. Spider plants, Swiss cheese plants and money trees from the house are jumbled up on my veranda with aeoniums and pelargoniums from the greenhouse, in a beautiful green chaos of leave textures and shapes. They look, to me, like summer, and it is time to admit that that is now over. Even in the south west of England it is not at all unusual for frosts to come along any day now. We don’t want a houseplant massacre on our hands.

The greenhouse plants are a little more borderline though. Clearly they are not hardy, but in a mild part of the country such as the part I live in, and in a city with its microclimate and many walls radiating trapped solar energy, plants such as aeoniums and pelargoniums can get through the winter outside. I know that many people in my local area do it, as I have seen them on outdoor windowsills in December and winced. An outdoor windowsill is a good place to place them if you are going to try this of course, particularly a single glazed window that will leak out the heat of the house to keep the frost away from the tender aeoniums, but it still feels like a risk too far.

It is time to tuck tender plants away into the greenhouse before frosts arrive.

Because of course in cold winters, such as last winter, these plants will be turned to mush and it is much better to get them indoors now. Aeoniums and pelargoniums are both a little tricky here, as neither would be happy with going inside the house. The heating doesn’t agree with them, and the light levels are too low, and they very quickly start to fade away and look sick, or to pick up a debilitating case of red spider mite. They are very likely not to last the winter or to die on going outside next spring.

Their ideal spot would be a cool conservatory, something full of light but attached to the house and enjoying the benefit of a little heat, while not being directly heated. A front porch can provide the same perfect winter conditions. I have neither sadly, and so mine go into a mini greenhouse. Unheated greenhouses, conversely, aren’t really quite warm enough for them. They will provide perfect shelter from winter rain, and this is important. Winter rain is one of the great killers of plants such as aeoniums and pelargoniums as it gives them soggy cold roots, which then sit, and rot. But really these plants could do with a tiny bit of heat in the colder moments.

My solution is to keep them in a mini greenhouse that I keep against the back wall of the house. The back is south facing and so it benefits from whatever winter sun can be had, plus receives a little heat from the house wall. It also means that they are close by enough for me to give them a little emergency warmth if they need it. I have put a tiny heater or even a propagation matt with its constant gentle heat in there during cold spells, and it has kept out the frost. The mini greenhouse is also small enough that I can stuff it full of horticultural fleece to keep the plants away from the glass and to prevent cold air circulating, and also throw a blanket or two over it. Time to tuck them away, anyway, and with luck I will be bringing them out to look pretty and summery next spring.