These apparently useless bits of junk are actually one of the most useful items a gardener can obtain. They can be easily turned into tanks and water butts, coldframes, hotbeds, compost bins and propagators, root, apple, potato, seed and tool stores and much much more.
Dead refrigerators & freezers are invariably free for the taking away, many are dumped that still work. Ideally working ones and those that still have the refrigerant under pressure should be degassed by qualified professionals; ask your local council. However a common reason why many stop working is that the gas has leaked out. This gas offers little direct danger to people or the immediate environment but indirectly causes climate warming. However once the gas in the system has gone the motor can be recycled for the copper it contains but no-one has much use for the cabinets. Unfortunately much of the insulation in the cabinets of older machines was foamed with similar gases. If this foam is crushed or degraded as happens in rubbish dumps then these chemicals are released. Thus we help if we re-use the cabinets preventing their being dumped and crushed.
Some may immediately object that they find the aesthetics of a scrap deep freezer unappealing in their garden. Once divested of badges and painted with black bituminous paint a dead freezer is just another neat rectangular box, indeed resembling nothing so much as an expensive metal tank, with a free lid! True they are still dead freezers but they are also extremely utilitarian objects.
The first and most obvious use is as tanks. Most chest freezers are designed to be fairly water tight anyway in case they go wrong and melt their contents all over the floor. Many have a drain plug in the bottom which must obviously be tightly shut and can also be used to attach a pipe and tap. Alternatively a pipe and tap can be fitted as a siphon (see my article in February's issue of Kitchen Garden). The lid can be left on to keep out dirt, kids and birds if the down pipe is passed through a hole. This is fairly easy to cut as the lids are made of two thin layers with insulation between and luckily there are usually no coolant pipes in the lids of chest freezers.
A good idea is to fill all internal joints and rivets with a gutter sealant in case any leak. As a coat of bituminous paint neatens the outside it does the same for the inside but is not actually necessary as most machines are lined with plastic, or aluminium which does not corrode as fast as the steel of a normal tank. Deep freezers are not designed to be full of water so some may bow a little if completely filled - but this has only happened to me once. They appear stable but obviously caution is recommended as to siting and footings as a big cabinet holds a great weight of water. And like for any water butt it makes sense to arrange the overflow to go to a soakaway and not erode the ground underneath the tank.
The next best use for a dead chest freezer, or even a refrigerator laid on it's back, is as a coldframe. The cabinets are designed to insulate, they are very good at it. If one is used to simply put plants in at night during the spring hardening off period it's very handy as this frees up greenhouse space. It can even be adequately kept warm for many hours by inserting a bottle or two of hot water when shutting it up for the night. By adding a sheet or two of glass or clear plastic the plants can then be left in the cabinet during colder days. Often there is a recess in the top of the cabinet sides that allows accurately fitted sheets of glass to sit there even while the lid is shut.
With a false floor to bring young seedlings up to the glass it is quite possible to raise tomato plants to fruit with almost no extra heat simply by opening the lid during the day and closing it before nightfall. Indeed because of the good insulation you are more likely to cook seedlings than chill them; good ventilation is essential as the trapped heat will reach scalding temperatures in bright sunlight. Never leave plants totally sealed under glass with the lid open in full sun.
To allow even more access to sunlight I have found it is better to tip the cabinet towards the sun by about twenty to thirty degrees. This lets more sun in but means the false floor is harder to construct though with a really thick bed of sand that becomes relatively easy. The other problem of tipping a chest freezer forwards, or setting a refrigerator at an angle on it's back, is it becomes unbalanced thus I have found it practical to set them into the ground by a foot or two. With a coat of paint a dead freezer then becomes almost unrecognisable and looks like a very expensive and professional coldframe.
Another way of letting in more light is to cut a large hole in the front, and possibly others in the ends, and setting in a glass pane or two. The front and side panels are harder to cut than the lid as there are pipes within, however neither these nor the sheet metal sides and the insulation are difficult to cut with a sharp hacksaw. Making more light enter the sides obviates the need for a false floor and allows bigger plants to be housed but decreases the total insulation offered.
Because of the excellent insulation and the depth of a chest freezer I have even found it possible to use one as both a propagator and coldframe by making a hotbed in the very bottom. Whereas traditionally a hotbed was fermenting horse manure and leaves I use a mixture of grass clippings, shredded newspaper, urine and compost. The cabinet is nearly filled with this mixture and topped off with a layer of sieved compost and topsoil. As the mass heats and sinks then more soil and compost are added on top and melon seeds sown on a mound immediately under the glass. As the mass sinks and cools the melon plants fill the remaining space and eventually hang out over the sides in the height of summer.
In a similar way a cabinet makes a superb compost bin. It may be a little difficult to fill and empty but the insulation means very high temperatures can be achieved with relatively small amounts of material. The enclosed fermentation may stifle itself so several mixings may be needed to stir in air and keep up a fast composting and likewise it may need to be a drier mix than you are used to as little moisture escapes. With over-wet mixes a drain hole in the bottom emptying into a tray will catch a supply of liquid feed.
With modern electrical aids a cabinet makes a very efficient heated propagator. By placing a soil warming cable and a thermostat in a layer of sand on the false floor a constant heat can be maintained very economically. (For security please have the electrics installed by a professional with all modern safety devices.) Because of the insulation a large cabinet with a glass lid may cost less to run than a flimsy plastic seed tray sized propagator and yet house six to ten times as many plants. It makes sense to site your new propagator in the greenhouse although this then interposes another layer of glass in the way of the light and thus reduces the rate of plant growth a little.
A completely different way to use a dead refrigerator or freezer is as a root, apple or potato store. For this they are entirely suited! Totally rodent proof your harvest can rest safe for months in an almost constant temperature and without drying draughts. It is similar to clamping but because the produce can be set on trays it has more of the benefits of a dark cellar. Almost no modification is necessary other than perforating the seal to let a little air circulate which helps prevent the contents going mouldy. Do not keep these different crops all together though as they cross taint, I'm sorry but separate cabinets are needed for each. If the store cabinets are set in a shady shed then the harvest is safe from almost any weather, left outdoors a cabinet will keep out most frosts but may need a bottle of warm water to tide the spuds through a week of hard frosts. Be warned though; most cabinets may leak thus needing a plastic sheet over them to exclude rain if they stand outdoors. Alternatively to prevent the spuds sprouting early I insert and defrost a bag of ice every so often which keeps a cabinet chilled.
A dead refrigerator also makes an excellent seed store as it can keep them cool and dry. For this the seal needs to be in good shape and the cabinet stood in a shady cool place. Including bags of the desiccant silica gel as obtained from camera shops will help keep the atmosphere dry and enable the seeds to keep much longer. If you do not need a huge seed store a fridge with shelves still makes a useful tool store, and one with a lock may be even more advantageous.
The wire shelves and baskets, and even the coolant mesh from some refrigerators, are also incredibly useful as bird and cat deterrents. The baskets are obviously also useful for storage but temporarily placed over seedlings and transplants efficiently keep off these big pests as do the shelves bent into inverted U shapes. Indeed almost every part has some use; even the wire flex and plug may be saved to fit some other device in the house.
P.S. Before you ask; at the last count I have eight working as water butts, five as propagators and coldframes, one as a seed store, one potato, one root and two apple stores, three keeping my chicken feed rodent free, three awaiting employment and two living in fear currently doing their proper jobs in the house.