When autumn comes around, gardening priorities shift from growing to storing. While summer vegetables require immediate attention to harvest, prepare and preserve, there’s no rush to harvest root crops in autumn. Many late crops such as swedes, beetroot, carrots, parsnips and turnips are quite happy to wait until you’re ready – a welcome relief after the hectic harvests of tomatoes, beans and courgettes!
Storing Root Vegetables in the Ground
It’s considered a good move to leave root crops in the ground at least until after the first frosts as this is said to sweeten their flavour, especially for parsnips. I have Neanderthal tastebuds that can’t detect the difference, but for the busy gardener it makes sense to leave your root harvest until a quieter time of year if you can.
There are some caveats, however. The longer root crops stay in the ground, the more likely they are to be found by pests like wireworm, slugs and rodents. Winter weather also plays its part in determining how long you can leave roots in the ground, because frozen soil is hard to dig and waterlogged soil rots roots. Use your best judgement and lift your roots in good time.
You can create a clamp to store harvested root vegetables for longer, but clamps are prone to infiltration by rodents and slugs and are probably not worth the effort unless you have loads of roots to store. Packing root vegetables into damp sand is much more convenient. If you can’t get your hands on sand (any kind will do), some gardeners use sawdust, vermiculite or coir instead.
How to Store Root Vegetables in Sand
Try to harvest on a dry day. Leave roots to sunbathe on the soil surface for a few hours before storing to kill off the root hairs and toughen up the skin. Don’t wash the roots, but brush off any loose soil and shear off the foliage just above the crown.
Before storing root vegetables in sand, check over your crops. Any nicks or gouges in the skin can rapidly turn to rot when stored, and it’s frightening how fast decay spreads from one root to the next. Use up damaged roots as soon as possible.
Wooden boxes and crates make good storage containers, but strong cardboard boxes are fine too. Plastic boxes are okay as long as they’re well ventilated, for instance by leaving off the lid. Spread a layer of damp (but not wet) sand on the bottom of your container then arrange your vegetables on top, making sure they’re not touching. Repeat, alternating between layers of sand and vegetables. Cap it all off with a final layer of sand.
Root Store Options
Store the containers somewhere mice and other rodents aren’t an issue, such as inside a rodent-proof garage or shed. The ideal place would be an unheated cellar where you can partition an area off to use as a root cellar. If you’re lucky enough to have such an area beneath your house, this website has detailed plans for making your own root cellar.
Alternatively, if you have the space and don’t mind the looks you could use an old broken-down fridge or freezer, whose inbuilt insulation will help keep temperatures constant. You can half-bury it into the soil for further temperature stabilisation. You might need to crack open the lid occasionally for ventilation, or pop in bottles of warm water to prevent freezing during very cold weather.
Climate Control for Stored Roots
Humidity control is very important. Wet roots will rot, and too-dry ones will turn rubbery and shrivel up. Temperatures should be kept a little above freezing but never drop below it. Sheds can be a bit iffy for this – mine gets very cold inside during the depths of winter yet on a sunny day can become a hothouse even in January – so choose your storage area carefully.
You can mitigate temperature fluctuations with insulation. Place your box of roots inside a bigger box then fill the gap between the two on all sides with some insulating material such as straw, bracken, or scrunched up newspaper. Or for a more permanent solution, partition off a section of your garage or shed and insulate it with sheet insulation. A vent with removable cover on the outside wall of the structure would probably be necessary to ensure sufficient ventilation. Keeping boxes of roots a few inches off the floor, for instance on lengths of wood, will help regulate temperatures too.
Whatever your storage setup, check stored roots every week or two to make sure there’s no sign (or smell) of rot, and remove any that have gone bad straight away. If your vegetables have started to grow, they’re too warm and you need to ventilate more. If they’re shrivelling up, they’re too dry – mist the sand to re-wet it.
If you can keep light, temperature and humidity under control you can look forward to garden-grown roots for months to come.