How To Create a Mini Indoor Greenhouse - Backyard Boss
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How To Create a Mini Indoor Greenhouse

When you think of a greenhouse, you probably imagine a structure made of glass or translucent material that gardeners use in colder seasons. They are made of transparent materials because the sun’s short-wave solar radiation can easily pass through the structure and heat up the soil and plants growing inside.

Greenhouses can help you prolong the growing season and grow plants during colder seasons. They also allow you to grow seedlings thanks to their humid environment, control the spread of weed seeds and shield your plants from harsh weather, pests, rodents, and other insects.

Fortunately, a greenhouse doesn’t need to be an elaborate structure. Instead, you can create a mini indoor greenhouse with materials that are either lying around at home or ones that you easily scavenge. If you’re looking to DIY your indoor greenhouse that won’t take up space or time, learn four ways to create four mini greenhouses perfect for your indoors!

Step-by-Step Instructions for Creating a Mini Indoor Greenhouse

Design 1: Plastic Bottle Greenhouse

Flower pot with upcycled plastic bottle as a greenhouse. Reuse used items concept. Sustainable home gardening. Low waste lifestyle. Craft waste free hobby. Blue minimal studio
Image credits: Troyan via Shutterstock

Depending on the height and spread of your seedlings, you can use this mini indoor greenhouse model to help them grow.

What You Will Need to Follow This Tutorial 

Box cutter Labels Marker
Upcycled Plastic Bottles Seeds or seedlings


Step 1 Wash your bottles thoroughly with a mild soap before using them for your plants. An unwashed bottle, especially one that previously contained sweet drinks, can attract ants to your plant.
Step 2 Cut across four to five inches above the bottom of the bottle. Either make this a full cut across, leaving you with two separate pieces or cut partially and leave the upper part of the bottle attached to create a hanging lid. The first option is helpful if your plant is already in a pot (like in the above image), whereas the partial cut gives you a makeshift pot and cover.
Step 3 With the first option, fit the lidded cut of the bottle half an inch into your potted plant’s soil. If you’re using the partially cut bottle, place soil into the bottom, moisten it and plant your seedling or seeds. Next, use the top part of the bottle, which is still attached to the bottom, as a covering for the bottom part containing the soil and seedling.
Step 4 Whether you use only the top part of the bottle and stick it into the soil, or use the entire bottle as a pot and cover, label it. Labeling helps you keep track of your seedling’s growth and requirements.

Pro-Tip: You can adjust the humidity within the greenhouse by removing or securing the bottle cap.

Design 2: Greenhouse in a Bag

This three-step tutorial is the easiest way to create mini-greenhouses for maximum germination. Since the bag will trap moisture inside, you don’t need to water the soil. Like a greenhouse, the light will warm the soil and plant inside the bag.

What You Will Need to Follow This Tutorial

Ziploc bags Potting soil or paper towel Spray bottle or measuring cup
Seeds Permanent marker Masking tape, sticky notes, or labels


Step 1 Place a wet paper towel or a few spoonfuls in your ziplock bag.
Step 2 Add the seeds of your choice into the bag.
Step 3 Label the bag with the date and type of seeds, then close it and tape it to a window to germinate.

Pro-Tip: As an alternative to sticking the bags to your window, hang a string across your window and peg your mini-greenhouses next to each other. Add two to three seeds per ziplock bag unless the seed is old or has a low germination rate.

Design 3: Plastic Punnet Greenhouse

plastic recycle box for plants
Image credits: TinyTall via Creative Commons

Here’s another upcycling tutorial that will give a new purpose to all the plastic punnets you have!

What You Will Need to Follow This Tutorial

Clear plastic punnet containers, preferably with a hinged lid Newspaper or tissue paper to make seed starters Soil
Seeds Marker Tape or label
Popsicle stick or pen to prop container open when sprouting starts


Step 1 Create rolls for your seed starters. These will be the little cups that you fill with your plants’ growth medium and place seeds in. To make tissue paper roll seed starters, divide the tissue roll in half. Then, make four vertical cuts on the roll, one-third of the way up.

On the bottom, fold the cut area like you would if you were closing a box. This will be the base of your tissue roll pot! Ensure the little pots are short enough to fit in the punnet while allowing the lid to remain on. If you want to make newspaper roll seed starters, use a shot glass, a little can, or a tiny jar as the mold for the newspaper.

Cut long, wide newspaper strips, then wrap them around the mold several times. Next, fold the newspaper’s edges over the mold, securely folding each edge. After that, take the can, jar, or shot glass out to reveal a newspaper mold of it.

Step 2 Poke a few holes in the punnet for drainage.
Step 3 Partially fill your rolls with moistened soil.
Step 4 Plant the seeds in the soil according to the package’s instructions.
Step 5 Cover the punnet and place it in a sunny area. Mark each roll with the plant’s name and the planting date.
Step 6 When you notice the sprouting, prop up the plastic container’s cover with popsicle sticks to encourage further growth.

Pro-Tips: Transplant the seedlings into a larger pot when they’re taller. But before planting, ensure you remove the cardboard from the toilet paper roll because not all soils will readily break down cardboard. However, you can bury the newspaper pots as is because the newspaper will break down.

If you don’t want to use newspapers or tissue, you can use disposable cups. However, they don’t retain moisture like the former options, and you wouldn’t be able to transplant them into a pot.

Design 4: Egg Carton Greenhouse

egg carton plants
Image credits: feserc via Creative Commons

This mini-greenhouse works wonders for seed germination. Your seeds will germinate more rapidly than they would on their own, thanks to the additional heat trapped inside egg cartons.

What You Will Need to Follow This Tutorial

Cardboard or plastic egg cartons Potting soil Your choice of seeds
Permanent marker Box cutter or knife


Step 1 Find a repurposed plastic bag or lid to use as a cover if you’re using a cardboard egg carton. Fortunately, you have a built-in top if you use a plastic carton.
Step 2 Make drainage holes on the bottom of each cup to keep seedlings from drowning and to enable drainage. In addition, make a few small air holes at the top of the carton.
Step 3 Fill the egg cartons with moist soil.
Step 4 Add three to five seeds in each little cup, following the planting instructions on your seed packet.
Step 5 Use a permanent marker to mark the day you planted your seeds and when you can expect them to germinate. It’s crucial to keep track of this if you’re using several different kinds of seeds in a single carton.
Step 6 Spray some water on them, so the soil is moist but not soggy, and then cover them with the lid or wrap the cardboard carton in a plastic bag. To prevent the soil from drying up, water once every couple of days.

Pro-Tip: Once the seeds have sprouted, remove the lid or the plastic so the seedlings can keep growing. You can place stakes to lift the plastic bag to keep the greenhouse effect going.

Turn Up The Heat!

How’s that for sustainable gardening? You can get your seeds to germinate by keeping them warm and moist with these mini indoor greenhouses. After they’ve outgrown their greenhouse, safely transplant them and prepare to grow new seeds!

Leave your experiences, thoughts, and questions in the comment section, and as always, please share!

Happy Gardening!

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