Updated at: 29-04-2022 - By: Sienna Lewis

To grow seedlings, you’ll need to construct a small greenhouse. The process of building a small greenhouse for your seedlings is simple. A single-plant greenhouse or a multi-plant greenhouse are both viable options. The materials we’ll use are low-cost, and we’ll demonstrate how to achieve both.

What is a Mini Greenhouse?

Seeds and seedlings can be germinated at home in a controlled environment by using a mini greenhouse. However, they do it at a considerably cheaper cost and in a format that is suitable for household usage rather than the big glass greenhouses utilized by professional growers.

Most small greenhouses include three essential components:

  • Initiation Point

As a drip tray and a base for the micro greenhouse, a robust plastic container is used to keep any water spills to a minimum.

  • The Tray for Seeds

Small plant cells or plugs are commonly used for seed sowing in a moulded seed tray that is attached to the base.

  • The Lid That’s Clear

If you have a greenhouse, the translucent plastic cover acts like the glass to improve the soil temperature and protect it from the outside weather and pests if it is used outside. Additionally, the lid acts as a barrier to keep the soil from drying out and the air from becoming too dry.

A Beginner's Guide to Using a Hobby Greenhouse ~ Homestead and Chill

Of course, this can all be done with a simple seed tray that is covered. Mini greenhouses, on the other hand, are more efficient because of the built-in vents that can be opened to more easily adjust temperature and humidity. These vents can be placed on the top of the lid for immediate airflow boosts, on the sides for more gradual control, or on both top and sides for maximum control.

These components work together to create a handy, portable, and successful germination and seedling growth environment.

How Can You Make a Small Greenhouse for Your Seedlings?

Here are two straightforward methods for building a small greenhouse in which to start your seedlings:

Using a mason jar for one plant

To build a micro terrarium, you can simply put one plant in the bottom of an empty mason jar with a cover. You may find Mason jars in a variety of sizes, so be sure to pick the right one for the plants you intend to nurture. Soil and compost should be added to the container. Design your terrarium as you like; just be sure to leave enough space for your seeds to expand.

Using a fish tank for larger plants

Consider utilizing fish tanks to make a greenhouse kit if a mason jar is too tiny for you. There is no right or wrong choice when it comes to the shape of your fish tank. As previously said, the tank’s size should be in line with the size of the plants you intend to cultivate.

For tiny greenhouses, a fishbowl is a good option. Depending on the demands of the plants within, you may want to cover it with plastic or leave it uncovered.

To mimic a commercial micro greenhouse in a larger tank, you simply flip it over. Cover it with plastic wrap or a wooden frame if you plan to leave it that way.

5 Easy Steps How Do You Start Seeds in a Greenhouse

It’s easier to manage soil and air temperatures in a greenhouse since seeds germinate more quickly under warm conditions. Sowing seeds in a greenhouse is as simple as the following:

Step #1. Place a tray or seedling pot inside a greenhouse

Fill the tray or pots with a potting soil mixture. Place a water tray with an inch of water and a tray of pre-mixed soil or pots inside. It’s best if you wait until the soil is moist but not soggy to water it. Afterwards, you can empty the water container of its leftover water.

Step #2. Sow the seeds

You can follow the packet’s instructions by planting your seeds in a mixture of soil and water. Make sure to plant two seeds in each pot or container. Spray a little water on the soil after planting if it’s dry and needs to be hydrated.

Step #3. Cover your greenhouse

Once your seeds are all set, cover your greenhouse and place it where it gets indirect sunlight. The ideal temperature range is between 65 and 75 degrees Fahrenheit (F). It is not necessary to water your seeds until after they have germinated if you cover the greenhouse.

Step #4. Open the greenhouse when seeds sprout

Allow fresh air into the greenhouse once the seedlings have sprouted.

Step #5. Water your seedlings

Remember to water your plants when the ground is dry. Pour water into the drip tray and use that to irrigate your seedlings. By allowing the soil to soak up water from the bottom up, you may keep your plants healthier and less prone to disease. Also, before your plants get too tall, remove the lid of your little greenhouse.

Why Are Small Greenhouses a Better Option?

Mini-greenhouses are an excellent choice if you’re searching for a greenhouse that’s easy to transport, practical to use, and small in size. The greenhouse functions just like a normal-sized one, even if it is little. If you’re still not convinced, consider these benefits of small greenhouse gardening:

Ideal for homeowners

Your favorite fruits and vegetables don’t need a large glass-walled greenhouse to grow. Large and expensive greenhouses aren’t necessary. A small greenhouse is more than enough for the ordinary home gardener.

Protect your plants from unwanted pests

Snails, caterpillars, rabbits, rats, and a variety of other creatures adore the flavor of your fruit. It would take a month’s worth of effort to get rid of these pests. You can keep your plants safe from hungry animals and insects by keeping them in a greenhouse.

Keep your plants safe from bad weather

Plants, especially the more delicate ones, can be uprooted by storms, blizzards, and heavy rain. You can more easily cultivate healthy plants in uncertain weather by growing them in a greenhouse. It doesn’t matter if it’s pouring or it’s storming outside; your plants will be protected and toasty.

Learn more about greenhouse gardening

All year round vegetables can be grown with greenhouse gardening. The cost of greenhouses, however, can be prohibitive for some. You may get a feel for how a greenhouse works before you invest in a larger one by using a little greenhouse. It’s cheaper than a greenhouse, yet it works just as well. You’ll be able to see if greenhouse gardening is right for you this way.

Commercial Vs. DIY Mini Greenhouses

A little greenhouse is a simple piece of gardening equipment, but you can construct a workable DIY version out of plastic containers and other everyday objects. Commercially available models, on the other hand, will be more durable, more able to regulate airflow thanks to well-designed vents, and better able to utilize available space.

When to Use a Mini Greenhouse

Many types of seeds can be germinated more quickly and reliably in a tiny greenhouse, but there are a few scenarios in which it truly shines.

Tomatoes, chillies, and other heat-loving tropical indigenous can only be grown in areas where the growing season is lengthy and hot. Using a compact greenhouse allows you to sow earlier in the spring and raise seedlings to transplanting size more rapidly, allowing you to extend the horticultural season by a few more weeks.

It’s also worth noting that some seeds are notoriously slow and unpredictable when it comes to sprouting. The sprouting of parsley, for example, can take several weeks, and if it doesn’t happen, that’s several weeks lost. These hesitant seedlings will germinate more quickly if you utilize a small greenhouse to speed up the process.

Cuttings can be taken in micro greenhouses, which provide a cozy habitat for new plants to establish their roots in.

A tiny greenhouse, on the other hand, isn’t ideal for all plants. For plants with long or sensitive roots, like carrots and beets, the benefits of earlier germination may be negated by the stress of relocation. Late-season direct sowing is usually preferable for these plants.

greenhouse setup | Diy greenhouse, Greenhouse plans, Greenhouse

How to Use a Mini Greenhouse

When using a micro greenhouse, caution should be exercised in addition to the usual recommendation to place seedlings on a sunny windowsill to expedite early growth. Under direct sunlight, even with the ventilation vents open, the glass lid can quickly rise to dangerous temperatures. Greenhouses should be placed in a location that is well-lit but not directly in the path of the sun’s strongest rays for best results.

Mini greenhouses are most typically used indoors, but they can also be used outside to provide some additional protection for your seeds. Use a little garden twine or even a few strategically placed rocks to help keep the lid in place and prevent bugs from getting inside.

Sow the seeds by filling the seed tray with fine compost and watering it thoroughly. Cover the tray with compost or vermiculite and spritz the seeds with a garden sprayer after you’ve placed two or more seeds in each of the tray’s cells.

Move the greenhouse to the germination location and secure the lid with the vents closed. Keep an eye on the humidity and temperature levels throughout the day, and open the vents if the greenhouse looks to be too hot or if condensation is building up too strongly.

Keep the compost moist until germination, and then remove the weaker seedlings from each cell so that each cell has one seedling left. GERMINATION: Each day, gradually increase the amount of time you keep the side vents open in order to let your plants adapt to a less pampered environment so that they are ready for transplanting or their final location.

Empty the compost and wash all components of the greenhouse with warm soapy water before utilizing it for another cycle of seed germination.

Optional Heat Mats

Adding a heat pad to your germination setup can take your tiny greenhouses to the next level. To keep the greenhouse at a constant temperature, heat mats consist of flexible plastic sheets carrying electrical elements that can be placed under the greenhouse’s base.

Heating mats can be used in chilly environments where low ambient temperatures can delay or prevent germination, or in rooms with inconsistent sunshine that lead to drastically varied temperatures. As a result, tropical plants that require constant high temperatures and humidity both day and night can germinate more easily.

Mini greenhouses can be used with or without a heating pad to assist you control the germination process and produce healthy seedlings that will grow into mature, productive plants.

How to Make DIY Mini Greenhouses

Finding out what you need is as simple as using your imagination and taking an inventory of your available space. These little, low-cost greenhouses can be grown on a patio or balcony. It is possible to employ greenhouses as both a decorative feature and an utilitarian one in your garden.

Plants benefit from the stabilization of growth conditions provided by greenhouses. It’s possible to keep your plants happy all year round by protecting them from extremes of temperature, wind, rain, and even pests like bugs and birds. I can get seedlings to germinate as early as February in these little greenhouses because I can regulate the temperature and humidity in them.

Garden Therapy’s Seed Starting Series includes this activity. Plan your yard for the coming year with the help of these DIY projects and gardening tips. The Ultimate Seed Starting Guide is an excellent place to get started in the world of seed starting.


Plants find it challenging to thrive in containers. Soil helps plants stay warm at night and cool during the day when they are planted in the ground. Because of the restricted amount of soil, the plants heat and cool themselves quickly in containers. To assist the seedlings grow, these little greenhouses are really crucial..

Your plant’s growth might be affected by the container’s size, material, and placement. For example, in the late winter, it’s cold and rainy with a probability of snow or frost in my area. For my early seeds, I opted for huge wooden containers such as raised beds or wine barrels. The earth can draw moisture from the air or release surplus moisture via the wood. The seedlings will benefit from the container’s enormous size because the soil will remain warm.


Use a shovel or garden claw to fluff up and stir last year’s dirt if you have a container. Our next step will be to replace the soil. Prepare some future nutrients for the seedlings by digging in a six-inch layer of compost beneath the soil’s surface.

Add a thin layer of moisture-retentive material to the soil surface, such as seeding mix, peat moss, or coconut coir, and then water the plants thoroughly. To germinate, the tiny seeds will have enough moisture and not enough soil crust to get out of the ground.


Because germination rates are lower in February, I plant more densely. For each barrel of wine, I typically use the entire package of lettuce seeds Since young salad greens are the first vegetables I get to eat fresh from my garden, I plant as many as I can and eat them all.

In the long run, this is a very cost-effective approach. For the months of March through July, I’ll thin and transplant lettuce all over the garden (and give some away to friends) all from one package of lettuce seeds.


At my local garden centers, I was able to acquire some excellent greenhouse covers at moderate prices. Throughout the year, I use them for anything from protecting tomatoes from frost to warming peppers and eggplants to protecting my rosemary from snow.

Tips for Buying or Making Mini Greenhouses

There are a wide variety of micro greenhouses to choose from, including these umbrella greenhouses. The following are a few things to keep in mind when shopping for small greenhouses:

  • Whether or not it has a vent is immaterial; you won’t be using it.
  • To avoid rusting, choose a model with plastic or rust-resistant elements, rather than one that looks like an umbrella and has the same metal latching mechanism as an umbrella.
  • The best greenhouses have a central stake (over the ones with pegs to hold down the edges). In order to check on the plants and give them some fresh air, you’ll lift the umbrella on a frequent basis. If you have to find and re-insert the pegs each time, this will be a nuisance.
  • When not in use, the best greenhouses may be folded up and stored.

As a follow-up, here are some links for those of you who have inquired about where to purchase one: Awning Greenhouses


It’s up to you, the gardener, to decide how to keep plants in micro greenhouses healthy. You need to keep an eye on your seedlings because weather and temperature conditions might change from year to year and from region to region.

It’s up to you now to decide when to water your plants, as rain will not do it for you. If the greenhouse becomes too moist or hot, you can either raise the greenhouse slightly off the ground or remove it altogether.


I begin hardening off my seedlings when they get their first genuine leaves and the weather begins to warm up. Slowly increase the amount of time they are exposed to the outside air by removing the cover for several hours each day.

Thinking about building a greenhouse? Here are a few things to consider | Opinion | toronto.com

Until I have a feeling that they will be safe in the moonlight on their own, I keep the containers covered at night. There is no need to fret, your magical gardener’s instinct will only improve with time!


I’m very hungry right now. Start by snipping seedlings at the base with sharp scissors to provide space for other plants to grow bigger. This is the most rewarding part. In the spring, baby lettuce, radishlings, and pea shoots are a treat.

In the garden, eat snow peas and use them to teach your dog tricks (my dogs are crazy about fresh peas). So many, in fact, that if you’re anything like me, you’ll have to schedule a 10:30 salad every day just to keep up with it. Enjoy!

Final Thoughts on How to Make a Small Greenhouse for Seedlings

There’s no excuse not to build your own mason jar and fish tank greenhouse for seedlings now that you know how to do it. However, if building your own small greenhouses sounds like too much labor, you may always purchase one already constructed. You’ll save money and have a long-lasting greenhouse with these.