What is a Garden Cloche? (3 Ways to Use Them)


Are you wondering what a garden cloche is, and what it is used for?  If so, you’re not alone.  I’ll try to give you some idea of what it is for and how to use it.

So, what is a garden cloche?  A garden cloche is a clear plastic or glass cover that is used to protect plants from cold, wind, and pests.  A cloche can also keep air and soil moist to help plants to survive during a drought.

Of course, there are many ways to make a cloche.  You can buy one or more ready-made cloches if you like.

There are also some cautions when using a cloche.  We have a lot of ground to cover with cloches, so let’s dig in.

What is a Garden Cloche?

According to Wikipedia, a cloche is a cover to protect plants from cold.  However, a cloche will also protect plants inside from wind and pests.

Most of the time, a cloche is used to cover only a single plant.  There are options if you need to protect multiple plants at once – more on this later.

The word cloche is French for bell.  Hundreds of years ago, glass cloches were adopted by the French, English, and Dutch for their gardens.

cloches
Some cloches were shaped like miniature greenhouses, but most were bell-shaped.

A cloche was useful for protecting plants from cold to extend the growing season of certain crops.  In fact, according to the Michigan State University Extension, U.S. President Thomas Jefferson used cloches in the gardens at Monticello.

However, there was an unforeseen consequence of using glass cloches: the greenhouse effect.

Sometimes, a glass cloche made the air too hot, which made life difficult for the plant underneath.  Now, many cloches are made of plastic instead of glass, and they have vents to avoid overheating the plants inside.

What Does a Cloche Look Like?

The original cloche was shaped like a bell.  The open bottom was wider than the dome-shaped top.

glass cloche
The original cloches were made of glass and shaped like bells.

Older cloches were made of glass.  However, this made it hard to vent them to cool down the air on hot days.

Now, most cloches are made of plastic, and they have vents included.  If you make your own cloches, you can be more creative about adding vents – more on this later.

How Does a Cloche Work?

A cloche works by the greenhouse effect on a small scale.  First, energy from sunlight warms up the air inside the cloche.

The warm air then heats up the soil.  The cloche itself keeps the warm air from escaping, and the air inside continues to heat up.

As mentioned above, the original glass cloches worked too well.  They would often make plants too hot unless they were propped open from the bottom with a stone or stick.

Now, cloches have vents that you can open to allow some cool air to get in.  This prevents the hot air from stifling your plants on a warm, sunny day.

When the vents are closed, a cloche can also retain moisture in the air and soil.  This prevents water from evaporating due to wind and sun.

Will a Cloche Protect From Frost?

A cloche can help to protect plants from frost, but there is no guarantee.  The reason is that a cloche may only offer a few degrees of cold protection.

frosted leaf
A cloche can help to protect against frost by providing some insulation from cold air.

For example, let’s say your cloche offers 3 degrees Fahrenheit of cold protection.  In that case, an overnight temperature of 31 degrees Fahrenheit would not cause frost damage to your plants.

The reason is that the plant experiences a temperature of 34 degrees Fahrenheit (31 + 3 = 34) inside the cloche.

Of course, the amount of cold protection from a cloche depends on many things, such as:

  • How much heat is trapped under the cloche (in the air and soil) during the day
  • Whether the vents are open or closed (close them before nightfall to retain more heat and offer more cold protection!)
  • How cold it gets overnight
  • How long it stays below freezing overnight
  • Whether you mulch over the soil around your plant or around the outside of the cloche
  • Whether you wrap a blanket around the outside of the cloche

If you do all of these things, you might be able to get several degrees of cold protection from your cloche.

A cloche can extend the growing season by helping your plants survive a late spring frost or early fall frost.

How Do You Use a Garden Cloche?

It is easy to use a garden cloche.  However, it is also easy to hurt your plants with a cloche, so take care!

First, you need a cloche large enough to cover your plant.

The cloche should be taller and wider than the plant itself.  If the cloche is too short or not wide enough, the plant’s growth will be restricted.

Next, you need to make sure that the cloche has a vent.

You can punch holes in plastic to form a vent.  Then, plug up the vent holes with a cloth if you expect an overnight frost.

You can also use the cap on a plastic bottle as a ready-made vent for the cloche.

water bottles
You can cut the bottom from a clear plastic bottle and use the top as a cloche. Remove the cap to make a vent.

Then, put the cloche over the plant.  If the soil is dry, you might want to water beforehand.  The only thing worse than a plant being too hot is a plant being too hot and too dry!

Finally, watch the plant closely when the cloche is on.  On a hot and sunny day, you may need to open the vents or even remove the cloche to prevent overheating.

Before a cold night with a threat of frost, you might need to close the vents.  You may even want to wrap a blanket around the cloche to provide extra cold protection.

If you need to, set an alarm on your phone to tell you when to put the cloches on (or open the vents) and when to take them off (or close the vents).

The last thing you want is to have your plants succumb to heat after you protect them from the cold!

How Do I Put Water In My Garden Cloche?

There are two ways to put water in your garden cloche.

One way is to simply take off the cloche and water your plants as usual.  The only problem is that this lets out all of the heat that you built up inside the cloche.

garden hose
Cut a watering hole in the side of your cloches, near the bottom, to prevent leaves from getting wet. Plug the hole with a cloth when not in use.

The other way is to open the vent and pour water in through the opening.  You can do this with a hose or a watering can with a narrow spout.

Just be careful about getting the plant’s leaves wet, since this can lead to rot and disease.  To avoid this problem, you could also make a small hole low on the side of the cloche for watering.

You can plug up this side hole with a piece of cloth, and take it out when you need to water.

What Can I Grow Under a Cloche?

You can grow any plant under a cloche, as long as the plant is small enough to fit underneath it.  However, a cloche is best for the following purposes:

  • Seed germination – for any seeds you sow directly into the garden (rather than transplanting), a cloche can keep the soil warm and moist.  This will provide conditions ideal for seed germination.
  • Seedling protection – after you transplant seedlings to the garden, they are at their most vulnerable.  They are not used to outdoor conditions, and a late spring frost could spell the end for them.  A cloche is a smart decision as part of the process of hardening off your seedlings.  If you want some more ideas on how to harden off seedlings, check out my article all about it here.
  • Pest and disease control – a cloche is a good option for protecting younger plants from pests and diseases.  For example, a cloche will prevent cutworms from cutting down tomato vines and other young plants in their prime.  A cloche will also help to prevent the spread of pests or diseases between plants.  You can also use a cloche to quarantine a plant that you suspect has a disease or pests.

One word of warning: be careful if you use a cloche on cool-weather crops, such as spinach or broccoli.  If a cloche makes them too hot, these crops might “bolt” as they try to make seeds to reproduce.

spinach
Spinach may bolt and try to produce seeds if it gets too warm for them under a cloche.

This will lead to bitter leaves on spinach and flowers on broccoli, which will ruin your harvest.  If you do use cloches to protect cool-weather crops, keep an eye on them!

Where to Buy a Garden Cloche

You can buy garden cloches made of many different materials.

For example, you can buy plastic cloches (set of 3) from Gardener’s Supply Company.  These cloches have a vent on top.

You can also find wire cloches such as this one on Etsy.  A wire cloche is useful for keeping rabbits and other animal pests away from your crops.

You can also wrap clear plastic or a blanket over a wire cloche to protect plants from overnight cold and frost.  Just make sure to remove a blanket in the morning so that your plants can get enough light during the day.

How to Make a Garden Cloche

If you want to make a DIY garden cloche, there are several ways to do it.

Clear Plastic Bottle Cloche

An easy way to make a cloche is to cut out the bottom of a clear plastic bottle.

For example, you can use a grocery container for water, milk, or juice.  Just be sure to rinse it out thoroughly first.  You don’t want to get mold in your cloche!

Also, be careful when cutting out the bottom of the container.  Use a clamp or vise grip to secure the bottle so it doesn’t slip as you cut out the bottom.

You can remove and replace the cap on top of the bottle as a built-in vent.  You can also punch holes in the sides of the bottle for extra vents or for watering.

Use a small piece of cloth to plug up these side vents or watering holes when they are not needed.

If you use the same bottle size for all of your cloches, it will be easy to stack them up for compact winter storage.

Wire Mesh Covered Cloche

Another option is to build a cloche using materials you might already have lying around.

For example, you can bend rabbit or chicken wire into a frame for your cloche.  Then, cover the frame with a piece of clear plastic or a piece of row cover.

wire mesh
You can use wire mesh as the frame for a cloche.

You can get row cover material online, such as this all-purpose row cover fabric from Gardener’s Supply Company.

This will provide some cold protection and also protect your plants from pests.  The wire frame can be bent back to a flat shape for easy storage during the winter months.

Metal Frame Cloche

Another way to make a cloche is to start with a sturdy metal frame.  Then, attach clear plastic sheets or pieces of row cover on the sides and top.

You can use metal bars or pipes of any length, depending on how tall the cloche needs to be.  Use twine to secure a plastic sheet or row cover in place, one piece for each side of the cloche.

Tent Cloche

This is just a miniature tent for your plant.  It doesn’t need to be completely closed off.

However, it can provide some shade for your plants on sunny days.  Build the frame (two upside down V shapes) connected by a support at the top, just like a tent.

Then, use a piece of row cover or shade cloth to cover the frame and make a tent for your plant.

Other Ways to Protect Plants

If you want to protect multiple plants from cold and pests at once, then you have several options:

  • Greenhouse – a greenhouse is a larger structure than any of the others.  You can use it to start seeds or to harden off seedlings.  You can also use a greenhouse to grow plants for their entire life cycle.  You can even use a greenhouse to keep some perennial plants alive over the winter.  You can build your own or buy a kit, but it will be expensive.
  • Cold frame – a shorter version of a greenhouse with a top that opens up.  A cold frame is good for shorter plants such as spinach and lettuce.  It can also be good for starting seeds or hardening off seedlings.
  • Hoop house – a hoop house is a tunnel-like semi-circle structure that protects plants from cold, just like a greenhouse.  You can learn more about hoop houses in my article here.
  • Raised bed – a raised bed can take many shapes and sizes, but it is basically soil that is raised up higher than the surrounding ground.  You can also put a cover on a raised bed to protect your plants from the elements.  You can learn more about raised garden bed covers in my article here.
  • Row covers – I mentioned row covers earlier, in the context of building a cloche for a single plant.  You can also use a row cover to protect an entire row of plants all at once.  A row cover is made of fabric that keeps bugs out, protects from cold, and lets sunlight through.  You can also use a row cover as an additional layer of protection for plants under a cloche or in a greenhouse.
  • Mulch – mulch is great for retaining water in soil.  Mulch can also help to keep the soil warm and prevent plants from succumbing to overnight frost.  Just remember that too much mulch can hurt your plants – you can learn more about that in my article here.
  • Blankets – at the end of the season, most of your plants are too big for cloches.  However, you can use a blanket to protect them from cold.  It might not work, but if the season is coming to an end anyway, it’s worth a shot.  Just remember to take off the blanket in the morning before a hot day!
supported raised bed
A raised bed provides better drainage for plants, but you will need a cover to protect against cold and pests.

Are you feeling adventurous, gardener?  If so, the Oregon State University has a DIY project on how to build a raised garden bed cloche here.

Conclusion

Now you know what a garden cloche is, how it is used, and how to make your own.  You also have some ideas on where to buy them if you decide to go that route.

I hope you found this article helpful.  If so, please share it with someone who can use the information.

If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here.  Enjoy!

~Jonathon

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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