Six DIY Indoor Greenhouse Ideas

If you’re trying to create a home for your vegetables, fruits, flowers, or herbs, but you don’t have the yard space for a full-scale greenhouse, an indoor greenhouse can be a viable solution. To create your indoor greenhouse, one of the first things you’ll have to do is to decide the size and design you need, and this all depends on what you want to grow.

After you build your greenhouse, you’ll either put it in a location that gets enough sunlight each day or rig up grow lights to supplement the lower light. Next, set up any additional supplies you need and start planting. If you’re curious as to what you can create when it comes to indoor greenhouses, this is for you. We’ve picked out six great options and outlined them for you below.

Indoor greenhouses come in all sizes and styles, and you can create one to suit your needs and space.

Why Build an Indoor Greenhouse?

Indoor greenhouses are starting to make a large comeback. Not everyone has the yard space to operate an entire garden, but, as it turns out, you don’t necessarily need a huge amount of space to grow crops.

For anyone who is cramped in a small apartment, adding an indoor greenhouse is a fun and simple DIY project that will give you many benefits. You get to watch your plants grow, and you can make adjustments as you need. It can be really nice to have a variety of edible plants right in your home. Also, adding an indoor greenhouse can really expand what types of plants you have inside. Houseplants are nice, but they can easily share some space with fruits, vegetables, or herbs.

Also, sometimes, even if you have the land for a garden, there are other complications that can get in the way of making it a functional choice. Maybe the soil isn’t good for supporting plant life, or the climate you live in seems to shift from freezing your plants to frying them in the sun. Or, maybe you have some particular plants in mind that are more high-maintenance, like orchids.

In many instances, if you can control the environmental conditions, you’re more likely to have a fruitful harvest. When you have an indoor greenhouse, you’re in total control. The set up cost is usually very cheap, and the amount of maintenance required is usually pretty low. With a freestanding, full-sized greenhouse setup, you can get issues like pests and plant diseases, and you may not notice it right away. You’re much less likely to have the issue with an indoor greenhouse, and on the odd chance that you do, you’ll see it right away.

Not to mention, you have a lot of chances to make your indoor greenhouse specific to whichever plants you want to grow, and the stylizing options you have are virtually limitless. We’ll dive into how to create several cute and functional indoor greenhouses below.

There are several reasons why you’d build an indoor greenhouse, and you can make them in tiny apartments or larger houses without an issue.

Recycled Plastic Container Indoor Greenhouse

Chances are, you have a few clear plastic, small cartons with lids attached collecting dust in your cupboard. You know, the smaller clamshell containers that are designed to hold take-out or salads. Some of them are disposable while you can reuse others, and what better way to recycle this plastic container than to make an indoor greenhouse. Best of all, it’s quick, easy, and you most likely have everything you need lying around the house.

Materials:

• Clear plastic container with a cover
• Potting soil
• Seeds
• Optional: individual or sectioned seedling cups, such as egg carton bottoms.

How to Make a Mini Greenhouse

Wash and dry your plastic container first. If you’re going to use seedling cups inside your mini indoor greenhouse, you want to fill them ¾ of the way full of potting soil. If you’re only going to use the bigger plastic container, fill it ¾ full with clean potting soil. Plant your seeds according to the directions outlined on the packet and water the soil enough to moisten it. Ideally, you’ll want a spray bottle for this step, and close the lid when you finish spritzing the soil.

Depending on your weather, the mini greenhouse can be used indoors or outdoors. Once the weather turns mild, you can put it outside during the day or by a sunny window. Whichever area you pick should get bright sunlight. Be sure to double-check and see if the soil is drying out when your greenhouse is in full sun. If the soil does start to dry out, you only want to add enough water to keep the soil moist. Bring this setup inside at night to help avoid chilling.

Your seedlings will start to emerge in a few weeks, and this will give you a head start on your spring planting. When they get too tall to fit into the lidded space, all you have to do is prop the lid open or remove it. As long as the temperature sits above freezing, you won’t need to keep your greenhouse under the lid, but don’t leave it outside at night. When the seedlings get too big for the space, repot them in a container until the frost danger passes. When it does, it’s time to replant them outside.

Grow Light Shelf Set Up

This simple setup will allow you to create a nice space for your seedlings to grow and thrive while the weather in your planting zone is cold. If you don’t want to buy a shelving unit and you’re handy, you can build one too.

Materials:

• 12 screw in hooks
• 12 x 7” lengths of chain
• 1 GORM Shelving Unit with 2 extra shelves.
• 6 utility lights with full spectrum or grow lights where available
• Power bar
• Wire or twine

How to Make the Grow Light Shelf Greenhouse

To start this project, build or assemble your shelving unit as the instructions tell you to. Space your top three shelves 15-inches apart as these are your growing shelves. Space the two shelves you have left as you want in the bottom as these are your supply shelves. Screw two hooks to the underside on both the back and front board, spaced two-inches in from the width of your lights.

Tire string or wire around the light and fix the end of a length of chain to each side. Hang the other end of the wires on your hooks roughly an inch above your seedlings, and raise the lights as the seedlings grow. Plug all of your lights into a power bar so that you can quickly and easily turn the whole thing off or on with one switch. Start the growing process by giving your seedlings eight hours of sunlight each day and slowly increase it to 12 hours a day. This will mimic the light your plants would get outside as the seasons change and the days lengthen.

Picture Frame Indoor Greenhouse

This cute indoor greenhouse uses picture frames you can get from the dollar store, and it’s a quick and easy process to give you a small terrarium to sit on the table.

Materials: 

• 8 lightweight picture frames; (two 8 X 10’s, two 5 X 7’s and four 4 X 6’s)
• Hot glue
• Paint brush
• Paint for the picture frames
• White duct tape

How to Build a Picture Frame Indoor Greenhouse

Once you get your frames home, the first thing you’ll do is paint them. Remove the backing and glass from the frames, and then spray paint them on both sides. Rustoleum semi-gloss spray paint is a good option as it’s durable. Once the paint dries, it’s time to put your glass back into the frames. Put hot glue on each of the four corners of each frame. You don’t want to add too much as it’ll show through the glass. Lay the glass in place and secure it using the metal tabs. Now, run your hot glue down the cracks between the glass and the frame. Once you glue all of the glass into the frames, it’s time to build your indoor greenhouse.

Run your hot glue gun down the side of your 5×7 frame and glue it onto your 8×10 frame. Keep gluing each frame until you have created a box with the two 8x10s forming the long sides and the 5x7s forming the short sides. Run your glue gun at each corner inside of the box to help secure it more.

Next, you’ll create the roof by gluing the 4x6s to each other lengthwise. You won’t glue all four frames together, and this is where the white duct tape comes in. This duct tape will create a flexible edge that will allow you to fold over the rooftop. You only need to tape the four frames together. It helps to have a second person around to hold the roof while you glue it into place. Put your greenhouse over your favorite plants next to a sunny window and allow them to grow.

Some indoor greenhouses are portable enough to bring inside and outside as the weather changes to maximize your growing conditions.

Windowsill Greenhouse

Greenhouses are a great way to help germinate seeds or look after your plants by increasing temperature and humidity levels inside the indoor greenhouse. They can also help seal out pests to protect the plants. This next indoor greenhouse is one you can put on window sills, and it uses only items you have around the house or can easily get your hands on.

Materials: 

• Big see through bag or any kind of see through plastic sheeting
• Pair of wire cutters, or a knife, or scissors (or even sharp rock
• Wooden skewers, or twigs/sticks
• Optional: Thread/string and superglue/glue to strengthen joints with.

How to Build a Windowsill Greenhouse

This is a very simple design for this indoor greenhouse, and you can modify it in all kinds of ways, depending on how much space you have and what you would like to grow in the indoor greenhouse. This particular design features one square on each end with a middle support going horizontal and a horizontal square in the middle to connect both ends.

There are various ways you can connect the skewers to create a stronger structure. You can use any sharp tool , but a wire cutter or sharp pair of scissors works very well. You do want to measure before you cut anything to ensure that you get a square structure. To strengthen the joints, drip any kind of blue over the joints and wrap a string or thread around the joint before knotting it to keep it in place.

Once you have the structure in place, get your large see-through bag or plastic that is large enough to pull over the structure to create the greenhouse. A second option you have is to cut the plastic sheeting or bags and glue them right to the frame. Try to tuck the bag under your structure to help seal it correctly to keep pests out and moisture and heat in. The roof portion of the greenhouse will allow LED lighting through if you choose to lay one on top.

Egg Carton Greenhouse

This is one of the most inexpensive indoor greenhouses on the list. After you eat the eggs, you can use the carton as a mini greenhouse. This is such a simple project that the kids can get on it and create their own planters with whatever seeds they want. Also, the egg cartons are biodegradable, so they’ll speed up the germination process.

Materials:

• Egg carton
• Plastic bag
• Potting soil
• Seeds

How to Make the Egg Carton Greenhouse

To start this project, you’ll take your empty egg carton and separate the top and bottom portions. Poke a hole in each space in the bottom of the egg carton to act like drainage holes. Fill the carton with your potting soil and sow your seeds. Spritz the soil with the water to saturate it before covering the whole thing with a plastic bag. Set it on a sunny windowsill and watch the seeds germinate.

Cup Mini Greenhouse

This is another mini indoor greenhouse that you can make with the kids. It’s actually a very fun activity to do at a party. You’ll only need a few things to create a greenhouse that is the perfect size for a single seed.

Materials:

• Clear plastic cups
• Dry beans
• Knife
• Painter’s tape
• Potting soil

How to Make the Cup Greenhouse

Fill your plastic cup halfway with potting soil and then wet the soil until it’s moist but not soggy. With a knife, poke three holes in the bottom of a second cup and set it aside. Let the kids plant two or three beans into the soil, and there is no perfect way to go about this. Barely put the seeds below the soil until they sprout. Put the second cup on top of the first and tape them together using painter’s tape. Set the cups in a sunny window, and you should see bean sprouts in four to seven days. You can transfer the sprout to a small pot if you like, but make sure there is a drainage hole.

Making tiny greenhouses is a great way to introduce the kids to gardening and get them their own plants to care for.

CD Case Greenhouse

The final mini greenhouse on the list is one made out of all of those old CD cases you have laying around the house. You want to have a few more CD cases than you necessarily need in case one or two break during the construction process. The finished result is going to be very sturdy and big enough for a few plants.

Materials:

• Craft knife, ruler and cutting board, to form a flat surface for the cases to lay on while they dry
• Old CD Cases (You’ll need 40 to make a greenhouse that is roughly 11″x 18″ x 20″) plus a few extras in case a few break
• Painter’s tape
• Plastic glue that dries clear.
• Safety glasses
• Tweezers

How to Make the CD Case Greenhouse

As long as you follow these steps, you could create this indoor greenhouse in a day or two.

Step 1: Prepare the Cases

Start by preparing your CD cases by cleaning them. You’ll most likely have to dust a few of them and remove any old price tags. A lot of the cases will also have balck plastic disc holders in them, and you only need the clear parts. Remove and get rid of the black plastic, and when you remove the disc holders, you’ll see a small space near the hinge. We’ll talk about this during the next step, but it’s nothing to worry about.

Step 2: Make the Walls

You’ll need four walls for the main portion of your greenhouse. The two end walls feature four CD cases in the design. The side walls have six cases per wall, and since all of your cases are rectangular instead of square, you want to orient them all the same way. All of the walls should have the hinges on either the right or left, and you don’t want them on the top or bottom.

Before you start gluing anything, lay your cases out and decide if you want the hinges on the right or left. Remember the open space we mentioned in step one? Make sure it faces down to give you one side that is solid, smooth plastic. For the end walls, put the hinges on the left to make a nice pattern, or put them so all of the hinges meet in the middle.

For the sides, arrange your CD cases so the cases on the left have their hinges on  the left and your cases on the right have the hinges facing right. You can alternate the cases in the middle. However you do it, once you decide on your pattern, you can glue the cases together. Start by making two end walls with four cases each before making the side walls with six cases each. Apply glue to the edges wherever a CD case touches another one, and make sure you line them up carefully so the walls are even when you lay them out to dry.

Step 3: Attach the Center CD to the Wall’s Peak

Once the glue on your end walls has set enough that you can touch your walls without disturbing how you put them, you can move to this step. Put the CD case in the middle of the wall, and use a rule to ensure it’s centered before gluing it into place. At this point, you should leave the walls to glue overnight before you move into the next step. You want all of the cases to be secure when you start cutting angles.

Step 4: Cut the Cases for the Wall Peak

It’s possible to cut CD cases using a craft knife with a little patience on your part. But, before you cut anything, you’ll want to put safety glasses on. When you’re scoring or snapping cases, there’s a possibility that the small plastic shards will fly. They can be as sharp as glass, so you don’t want them in your eye.

The most important aspect of this step is getting the angles correct. Starting with the right corner of the peak, put the whole case in an empty area with the hinge facing to the left and the open space down. Lay a ruler across the case so the edges line up with the corner of the full cases next to it and below it. Use the craft knife to score a line across the case that you’ll cut.

Once you mark the case, flip it over and line the ruler up so it looks like it matches the originally scored line on the other side. Score a new line on this side of the CD case. Now that you have both sides marked, you want to open the case up so it lays flat and score matching lines on the inside.

Using a decent amount of pressure, cut over all of the lines on the inside, front, and back repeatedly. You’ll also cut the plastic on the edges of the case where your back and front lines match up. After you go over each line several times, you should cut through in various spots. You can snap the case at this point. To do this, apply pressure very carefully along both sides of your score line until it cleanly snaps.

To create the top peak, you’ll need to cut a triangle. You do this the same way as the side pieces, only this time you’ll mark the angle by placing the ruler along the corner pieces that you just cut.

Since most people have CD cases laying around, this project is usually something you can do in a weekend or two without any issues.

Step 5: Glue the Walls Together

Once all of your four walls dry, you want to stand them up and face each wall so that the open spaces are on the inside. It’s slightly harder to glue this way, but you’ll get a smooth wall on the outside. Glue the edges of the walls, holding them in place with tape until your glue dries.

Once the glue sets, you may notice weak areas or gaps. If this is the case, you’ll use your glue like caulk to reinforce your joints. Run a bead of glue up the inside corners where every wall meets. Wipe most of the glue away right away with a paper towel, moving with the bottom of your wall in a straight line towards the top. During this time, you’ll apply a little pressure with your finger to force the glue into any gaps.

Step  6: Make the Peak of the Roof

To make the top of the roof, you’ll bend four CD cases in half and line them up to form the peak. In order for your roof to lay flat to the walls, the plastic edge on the short side of the case needs to get cut off. This is the opposite area of the hinge. Once you cut all four CD cases, it’s time to set the roof angle. Put some glue on the hinges of two CD cases and allow them to dry.

Once the glue dries, this will keep the case at the correct angle. You can now use it as a template to set the angle on the last two cases you need to form the peak of the roof. Remove the cases from the balancing palace on each wall and set them on a flat surface. Before you glue them all together, line them up so the openings alternate sides. The cases will fit together better this way. Glue the remaining two cases to the ones you already glued on this angle, and use tape to keep the angel matched until the glue dries. When both pairs are set up, glue all of the cases together so you’ll end up with four cases on top of the roof at the correct angle.

Step 7: Finish the Roof with Folding Panels

The final step to create this indoor greenhouse is to finish the roof. You’ll need four cases for each side of the roof. Open the CD cases so that they are laying flat, and glue the edges together to make a panel. Be careful that you don’t get glue into the hinge or the panel won’t fold up correctly when they dry.

On one side of each case, you’ll notice three raised plastic edges. The other side will have two raised edges and a flat edge. You can put two panels on the roof so that the side with the flat edge is at the bottom closest to the walls. You can put the panels however you like as it’s an aesthetic choice. Put the panels so they overlap on the roof’s peak, cover the open area of the roof, and overhang the walls slightly.

Be sure the flaps fold up or else you won’t have panels that open for ventilation and watering. Glue along the top as well as the front and back sides. Use tape to hold the panels in place until the glue dries. Once the glue dries, remove the tape to get a very strong, light, CD case indoor greenhouse.

Bottom Line

These six DIY indoor greenhouses are something that you can do in a weekend, and they’ll give you fun space for your plants to thrive. Create one or create a few and see how they improve your indoor space all year-round.