12 DIY Mini Greenhouse Plans You Can Build Today (With Pictures) | House Grail (2024)

• Pete Ortiz
• Last updated: Feb 27 2024

Greenhouses allow gardeners to extend the growing season, protect plants at various stages of their lives, and even allow some storage space for gardening implements and items. They can take the form of cold frames, polytunnels, or full greenhouses, and while some of the most impressive structures can cost thousands, it is possible to build a greenhouse that matches your requirements using some household items or leftover DIY items.

Below are 12 DIY mini greenhouses you can build today including seedling greenhouses, those made with plastic umbrellas, and full pallet greenhouses. Your build may need to be modified to better match the items and materials you have on hand but the plans make an excellent starting point to provide inspiration and general ideas.

The 12 DIY Mini Greenhouse Ideas

1. Dollar Tree Greenhouse Seedling Starters

At its simplest, a greenhouse is really just a protective, clear covering that surrounds the plants. One can be very beneficial when used to protect seedlings, allowing them ideal conditions to grow and flourish without the danger of them being badly damaged in bad weather. These dollar tree greenhouse seedling starters couldn’t be simpler as they just use upturned plastic contains from the dollar store. Because the containers aren’t modified or damaged in any way, they could be reused or cleaned and repurposed once the seedlings are transplanted.

2. Mini Greenhouse

This mini greenhouse is just as simple and equally as functional as the dollar tree greenhouse, but it could work out even cheaper. It uses plastic salad tubs—the type with lids—and because you can put the lids on the salad tubs, it even allows you to stack several of the containers, taking up less room than placing them side by side. The plans also show you how to turn yogurt pots into seedling containers, although you may not need this if you already have pots.

3. Dollar Store Plastic Umbrella Mini Greenhouse

Another hack that uses dollar-store items is this dollar-store plastic umbrella mini greenhouse that uses your existing plant pots and a cheap, clear umbrella. There’s no need for any sawing, screwing, or other modifications to the umbrella and you can even leave the handle on. The premise is simple—open the umbrella and bury the pole in the middle of the pot so that the umbrella completely covers the plants in the pot. If it’s a tight fit, that’s even better, and you can bring the edges of the umbrella over the pot to provide total protection.

4. Mini Greenhouse Shelf

The mini greenhouse shelf brings a little more order to proceedings and starts to look like a traditional, commercial cold frame, but it is still really simple to make without having to use any power tools or make any major adjustments to the items in question. Essentially, you just place some plastic sheeting over a plastic shelving unit. It does mean you have to pull the sheeting up whenever you want to get to the plants underneath, but it really is a simple and effective way to keep your seeds and seedlings safe while they develop.

5. DIY Mini Greenhouse with Hula Hoops

Polytunnels, or hoop frames are beneficial because they can be placed over the existing ground so you can plant directly into the soil and use the natural nutrients in the ground to feed and nourish plants and flowers. This DIY mini greenhouse with hula hoops uses the hoop frame concept, turning half hula hoops into the hooped frame section. These are attached to a wood base and covered with painter’s plastic to protect the plants underneath. The greenhouse is easy to make, with the most difficult aspect is drilling holes in the wood for the hula hoops.

6. $20 Simple DIY Mini Hoop House

This $20 simple DIY mini hoop house creates the same effect as the hula hoop model above but rather than using hula hoops, it uses PVC plastic piping. PVC pipe can be bent, although you do need to take some care to ensure it doesn’t fold, and the ends of the pipe can be placed over landscape stakes which means that you don’t need the wooden frame at all, therefore negating the need to even have to drill perfectly circular holes. What’s more, because it doesn’t have a fixed frame, the mini hoop house can be placed over any bed, regardless of its size or shape.

7. Mini Greenhouse for Raised Beds

PVC pipe really is flexible, especially when you combine it with the variety of joints and connectors that are available. When using it to make the frame for a mini greenhouse, you don’t have to worry about making the joints watertight, either. This mini greenhouse for raised beds is ideal for those plants that you need to keep off the ground. You may need to saw some of the pipes to ensure that the frame perfectly fits the dimensions of the bed, or make sure you buy the right lengths of pipe. The design has a slanted-roof style finish, which prevents rainwater from pooling on a flat top.

8. Pallet Greenhouse

Pallets are the unsung heroes of garden DIY projects. They are built to be strong, made from decent quality timber, and are reasonably easy to pull apart if needed. This pallet greenhouse is a triangular shape, which fits really well leaned up against a wall or against a shed. It uses a polycarbonate sheet and it has a hinged door to access the plants inside. It does require a little more work than turning a plastic container over, but it also has a more permanent finish and only costs you as much as the plastic sheet and whatever you pay for the pallet.

9. A DIY Greenhouse With Old Windows

Pallets aren’t the only wooden item you can repurpose in the garden, and when it comes to finding the ideal items to turn into a greenhouse, glass windows are an ideal choice. They already contain the glass that will do a lot of the work in your completed greenhouse, and old windows can be picked up fairly cheaply from reclamation yards and potentially even your own garden shed. To make a DIY greenhouse with old windows, you will need to first claim what windows you can, ideally along with a glass pained door, and then work out the dimensions you can achieve. You are likely to have to use other materials like pine and Sunlite panels to help finish the construction and block any holes, but it will be cheaper and a lot more satisfying than buying a readymade greenhouse.

10. Inexpensive DIY Greenhouse

If you want a full greenhouse, rather than a cold frame or hoop greenhouse, this inexpensive DIY greenhouse uses cattle panel fencing to create a curved structure and combines this with a wooden frame for stability and strength. The result is a greenhouse that looks almost store-bought. Using the pictures as a guide, you will need to determine measurements and supplies yourself, but it is great inspiration.

11. Build a Greenhouse Cheap

We’re stretching the idea of what constitutes a mini greenhouse, but as this plan costs less than $200 to make, it certainly has a mini price tag when compared to buying a commercially made alternative. Using 2×4 and 2×2 wood, as well as poly sheeting, you can build a greenhouse inexpensively that will do an admirable job of protecting plants and it looks like a professional greenhouse when finished.

12. Pallet Greenhouse with a Rain Gutter Grow System

While it definitely doesn’t qualify as a mini greenhouse in terms of its length, this pallet greenhouse with a rain gutter grow system shows how far you can take your DIY greenhouse project. Rainwater is the best water for your plants. It’s free, can be collected fairly easily, and using this video you can learn how to install a grow system that benefits from this natural resource. You can always use the same techniques and a similar design but scale it down to fit in the space you have available for your garden construction.

Conclusion

A greenhouse, whether it is a full greenhouse or a cold frame, enables you to extend the natural growing season in your area. It can protect seeds and seedlings while they mature and affords you the option to bring delicate flowers and plants in out of the rain or any unseasonable cold snaps.

Using the plans and guides above, you can build your own construction according to the space you have available and how you will use your space. If you have items like pallets or old windows, these constructions can cost very little, and even if you do need to buy materials, PVC pipe and 2×4 aren’t the most expensive building materials to use.

• Related Read: 8 DIY Raised Bed Greenhouse Covers You Can Build Today

Featured Image Credit: Caterina Trimarchi, Shutterstock