Image: Jamie Spooner wrapping a small banana plant Musa Basjoo with fleece and straw in a previous year at The Exotic Garden
This can be done in degrees, dealing with the tenderest planting first, especially when you consider that tender perennials hail from tropical and sub-tropical parts of the world or are hybrids of such plants. Here at the Exotic Garden in Norwich we never (well not over the last 30 years) get frost before the beginning of November, well certainly not killing frost! Obviously – in more northerly parts of the UK and gardens that are in a frost pocket or wide open space which get frosts far earlier than this.
For this reason, I think one of the most important items to have in your garden is a max/min thermometer, so you can not only see what the daytime temperature is, but more importantly how cold it is getting at night.
Cold air flows downhill so if you have a sloping garden I would suggest having at least two thermometers to find the warmest and coldest parts of your garden. Make sure that your thermometer never gets direct sunlight on it as you want to know the air temperature. Also, it should be around three and five feet of the ground. [ This one is good ]
If you live in an open edged garden with fields on either side your garden will tend to get colder than a garden that is surrounded by tall shrubs and trees or if you live in a city – this is called a microclimate which I will talk about in future blogs.
Most people do not have a greenhouse so are reluctant to grow tender plants, though many gardeners I know put their prized plants in frost free garages, bedrooms, bathrooms, even living rooms, if you like living in a jungle during the winter months! In the US most houses have a basement which can be utilised for over wintering. I would always suggest that wherever you keep them it is cool and not warm as light levels are low indoors and you plants will get stretched (this is known as eteolation), hence the cooler your plants are kept, the better, as you want them to go dormant.
If you are protecting plants outside, large flowerpots or similar, can be stuffed with straw and placed over the top. Larger borderline plants can be wrapped with horticultural fleece or hessian (burlap) and for added protection straw can be used as well. [ Try here for fleece ] If you are overwintering in a greenhouse or Polly tunnel, you can either have them unheated or heated though this can be expensive, but worth it if you’re a plant nut like me! Although electricity is the most expensive form of heating it is the driest as paraffin or gas heaters create a lot of moisture which can cause botrytis (mould) to build up. I will talk about all these methods in weeks to come.
Meanwhile here are a few things to consider and do in October
1. Buy min/max thermometers if you haven’t already – [ Try Here ]
2. Think about where you will store your plants over winter
3. Buy heaters to protect from frost – [ Try Here ]
4. Buy in your gardening fleece or hessian protection – [ Try here ]
5. Get in your straw [Any straw is fine here – Pet shops are good for this & cheap]
6. Find your pots or large containers to put over your plants [You usual garden center]
7. Think about other forms of protection – is there anything else you could do?