How to Make a Rooftop Garden : 101

Are you a city dweller? Love gardening or wish to? Have a box of questions of confusion, how to make a rooftop garden?

Be cool.

I explain everything here to wash out all of your confusion and show you some solution to your headache.

In urban areas, there has some limited space for living, so manage some place for your garden is not possible literally. But if you think vertically, it is still possible transforming your apartment building roof into a charming outdoor garden and enjoys the flavor of the Mother Nature.

How to make a rooftop garden

Benefits of roof gardening

  • Best uses of available places on the roof.
  • Roof gardening can develop the air quality and protect your building from overheating.
  • Attracts the wildlife like bees, birds, butterflies and other species.
  • No wild animal hazard like deer.
  • Create a private place for passing your leisure.
  • Roof garden is the symbol of urban agriculture.
  • It can balance the temperature in summer and winter which can reduce the demand for using extra energy.


Difference between green roof and roof garden

First of all, you need to be clear that, I am talking about roof gardening, not green roofing.

Roof gardening can be different based on your design and demand. Sometimes it covers the whole roof as a regular garden, and sometimes partial part or sometimes uses pots or raised bed. Roof gardening mainly focuses on recreational activities, growing plants, creating an outdoor place for entertaining people and spending quality time.

On the other hand, green roof mainly uses for covering the whole roof for strengthening building structure. It also saves energy by controlling the building temperature in summer and winter season. Moreover, it saves your money and the environment.

So, if you are looking for the answer of making a roof garden then continue reading.


Tips for making a rooftop garden as a beginner:

You need to ensure first, you must have an unused open roof either rent or own an apartment in a shared building. If you haven’t, don’t waste your time and money moving further. You better start an indoor gardening or balcony gardening.

If you have a roof, the following steps to consider building a roof garden.


1- Getting permission

Check with your local planning office for the ordinances or city’s building codes to ensure, if you are allowed to start a roof garden in your area.

If you live in a rented house or an apartment in a shared building, you must take permission from the landlord, condo organizations or homeowners association for beginning a rooftop garden.

If the laws allow you to do so, you can go for it.


2- Contact an engineer

Consult with a licensed building expert or architect about the possibilities and challenges of starting a roof garden in the building where you are living. Some buildings do not have the capacity to hold the extra load. On the other hand, some buildings able to take a limited amount of weight.

You don’t need an architect to complete the whole roof garden design. But an architect or building expert or a contractor can explain to you the loading capacity of your building including your plants, garden containers, other required equipment, furniture, people and weather loads like snow.

Even if your building can handle the extra weight, try to use lightweight materials like plastic, fiberglass or foam planting containers. In addition, use coco peat or lightweight potting soil to set up your garden.

Remember, your garden design mostly depends on the weight capacity of the roof. Besides, consult with an engineer which materials would be best for your roof drainage system.

Safety first, only protecting the roof from falling off or weight capacity doesn’t cover all things. You have to ensure the safety of the passerby from falling tools because roofs are commonly windy places. So round your roof with fencing. You must follow the guidelines of fence height according to the local garden law.

Don’t try to skip these steps and try secretly continuing gardening on your roof. It will cost you and find yourself liable for damage and injury.

At the same time observe the roof’s general condition, if any upcoming maintenance required, you may have to move your planters and other structures, which would be expensive.


3- Approximate cost for roof garden construction:

This is hardly possible to determine how much does it cost to build a roof garden. There have a lot of factors which may vary the cost of making your roof garden such as:

  • Which method do you choose for your roof? Container on the terrace or raised bed on the roof or a permanent one like ground level gardening.
  • Weight capacity and present condition of your building influence the gardening budget. If the building roof needs a routine repair or maintenance before starting a garden, it can merge the garden construction cost.
  • Your garden design mostly depends on the load capacity of your building roof. If the load capacity of your building is not enough, you must have to apply simple design which can reduce your cost.
  • You just need a building consultant to know the exact condition and further procedure to build a roof garden, but a landscaping designer is not essential. So, if you design your own garden, you can reduce your cost.
  • If you choose costly plants which are not available in your area, it will raise your gardening cost.
  • If your roof has no water supply system, you have to create one, and it will increase your cost.
  • Besides, creating drainage system and installing auto irrigation system can raise your garden budget.

Typically, roof gardening construction cost is a bit higher than a conventional garden cost. It starts from $20 to $200 per square foot based on the above factors and some other hidden or situational factors. To get a more specific idea about the costing, consult with a building expert or landscaper.


4- Sunlight exposure

Sunlight plays an important role in growing any plants. So, observe your roof carefully how much daylight it receives all day long. Besides, check the year round for understanding the time frame of sunlight and shade.

Moreover, sunlight determines which plants grow well in your garden. If your garden receives enough daylight without any obstacles for 6 to 8 hours, choose the plant varieties to grow well in sunlight.

On the other hand, if the garden receives limited sunlight because of neighboring buildings most of the day, choose the shade-loving plants.


 5- Water supply and drainage

There are multiple ways to start gardening on the roof like container gardening, raised several beds and planting or prepare your whole roof as a garden. So, before starting a garden, you have to make proper planning for your rooftop garden irrigation system based on which gardening method you follow.

There are several methods of the irrigation system, and they depend on the design of your garden.

Arrange a water storage system based on the demand of your garden size. Your garden needs daily watering because of the wind and the sun exposure. So, providing the required water supply can make the best of it.

You can use an automatic drip irrigation system or plastic bottle watering system or manually water your plants if your garden is too small.

Besides, the proper drainage system is essential when you are planning for your roof garden construction, and it also depends on the garden design you choose. To protect your roof from damage put plastic trays or rubber layer beneath your containers or beds to help them drain easily.


6- Wind exposure

A rooftop garden is windier than a backyard garden. Besides, if your building is higher than the adjacent buildings or not surrounded by high rise buildings, the wind will be extreme. A strong wind can harm your plants, damage your garden structures and occur an accident.

Don’t try to put a plain block shield to prevent such a strong wind because it can happen more damage. You better control the wind by reducing its force using trellises or some wide structural frame.

When selecting furniture or other essential materials for your roof garden, always avoid the lightweight equipment.


7- Soil and container

When you are going to start a garden on the roof, you must need to consider the soil mix, and it must be lightweight. You should not use the same soil mix using for a ground level garden because normal soil mix is heavier than the special lightweight potting soil mix.

In order to make a lightweight potting soil mix, you need to collect vermiculite, topsoil, coir fiber or coco peat, limestone, compost, coarse perlite, and sand. Moisten those ingredients and combine them perfectly.

This potting soil mix will be lighter than other garden soil mix and improve your drainage system.

Pick up the right container for your garden is also important. You must choose plastic or wooden planters for your roof garden and try to avoid terra-cotta or concrete planters to reduce the extra weight.

If you want to cut off your expenditure, you can arrange some old plastic buckets or kids’ bathtubs, small size plastic drum, coffee cans and other unused wastage materials which can hold enough potting soil for garden plants. Make some holes at the bottom of the collected planters for releasing extra water.


8- Plant selection for a roof garden

Selecting plants is the main part of your garden, and it depends on the purpose of use, weight load, garden design, space, structure, and sunlight and wind exposure. So, you must choose carefully the plants you are going to grow.

  • If you want to create a vegetable garden, make sure your existing garden decoration, load capacity, space and other factors allow the varieties you choose.
  • If your roof surrounded by high rise buildings, never choose the varieties to need full day sunlight, rather choose some shade-loving plants. Besides, try to avoid those plants which can’t survive in a strong wind.
  • On the other hand, when you are going to start a flower garden, you can pick any types of flowers. But, remember the sunlight and wind exposure as well as avoid those plants which grow taller and spread branches.
  • If your roof garden receives enough sunlight, you can grow some edible plants on it. There has plenty of varieties, and you can try different variety each year.
  • Selecting native and drought-tolerance plant varieties are the most important part of plant selection. The native plants attract the bees, birds and other pollinators in the garden. So, always pick up the local plant varieties for the betterment of nature.


9- Electrical wiring

If you want to arrange a party in your roof garden at night, you must need a provision for lighting. Besides, it is also essential when you need to work at night in your garden.


10- Storage box

Installing a storage box on your rooftop can save you time and labor, and make easier your work. You can keep garden tools and other necessary things in the storage box to find them easily. You can simply turn your system box into a table or seating bench in a decorative way.


11- Roof Maintenance

Routine checkup of your roof is essential when start gardening. Regular inspection helps you to avoid the unexpected damages and save your money. Make your own checklist and timetable for the routine checkup of your building roof.

Check the interior of your building, if there any sign of water damage-repair immediately. It may happen for high snow falling or leakage of water supply, or your building roof takes an extra load for your garden.

Waterproofing your roof membrane is essential to protect it from water damage. Besides, plant roots can do harm your roof sometimes, so use root repellant if required.

Make sure your roof is free from fallen leaves and tree limbs or dart and debris, which can clog your drainage system.

Pipe and other equipment fittings are one of the main parts of roof maintenance. Check the fittings and make sure there has no leakage or dropping water. If so, repair it immediately.

Recheck your old repairs and drainage system too and always keep your roof dry and clean.


12- Weeds and pests

Spend some time weeding and filtering dead leaves in your garden. Check regularly, if your plants are attacked by bugs and diseases. Remove the detected leaves and plants as soon as possible and use organic pesticide if required.


13- Winter care of your garden

First of all, you have to find out what type of protection do your roof garden need during winter. You can study the USDA plant hardiness zone for understanding the average minimum temperature of your garden location. Most importantly, it may depend on the micro-climate of your garden location-like sunlight and wind exposure and the surroundings.

After acquiring the knowledge and observing your garden location and environment, you can take some need-based actions to protect your garden from winter.

The rooftop atmosphere is more challenging than ground level garden location, and it becomes harsher in winter. Try to select those plants which need less protection and hardy enough to survive during the winter season and avoid picking the tender plants.

You better choose slow release fertilizer rather than high nitrogen fertilizers at the beginning and late in the year for more precaution. It will help you to minimize the risk of damaging effects of your garden plants.

In addition, covered your garden plants with a black plastic layer to protect from the morning sun and heavy snow is falling. The morning sun can harm the growth of plants during winter.

Some low-growing container plants can be moved inside your house for the protection.

Mulch your soil to keep them away from freezing, and this will help keep moisturizing the soil during winter.

Use frost proofing garden container for protecting them from cracking. As well as apply compost soil with a mixture of straw and old leaves, which will make easier the drainage system and keep the soil moistened.

A light layer of snow works as an insulator and protect plants from cold and frost. But, when you face heave snow falling in your garden, shake the trees and shrubs to remove snow before they are broken.

If you create a greenhouse for protecting your garden from winter, don’t let the snow stay on your greenhouse roof for a long time. Remove the snow immediately before it damages your roof and frame.

You can check out here for details about winter protection of your garden.


14- Beautify your garden

No matter, your garden is big or small, the proper decoration will give it a beautiful look. Make a sitting arrangement for guests in your roof garden. If you haven’t enough space, at least keep a deck chair for you personally or some folding chair for limited guests.

This little sitting arrangement will give you pleasure and inspiration to go for an extra mile. Because only work without entertainment can make you feel bored after someday and you may give up. Make your garden as a place of fun and work.

You can also put some garden light in your garden to make it more gorgeous. In addition, you can set up a water fountain in a suitable place on your rooftop garden.


Disadvantages of a roof garden

It goes without saying; roof gardening can benefit you in many ways. But it also brings you some problems.

Don’t be scared.

They are not unsolvable!!! But regarding the issues before starting a garden can help you to make a proper plan, and reduce the risk of failing.

You need to know that, garden containers and raised beds can damage your roof for holding extra weight, and strong wind can harm your plants and seedlings.

It will be challenging if your roof has no options to get a connection of water supply. Besides, any leakage of water can damage your roof, moreover without a proper drainage system water can soaking down from your roof to outside.

The initial investment for a roof garden is costly, comparing a ground level garden. Regarding the safety issue of the building and the surrounding people, insurance company especially charges a higher rate for the roof garden. When you start a garden on the roof, regular maintenance is essential, and sometimes you cannot handle it without the help of an expert hand, and this is expensive too.



Just keep the above tips in your mind when you plan for a roof garden. Every action in our life has some good and bad effects as well as every problem must have a solution. Proper planning, patience, and passion, investing time and money in the right way for your garden can make the best of it.

No matter how big or small your garden is! It will bring you peace and give an opportunity to spend some quality time with Mother Nature.

Good luck and happy gardening.



John Michael
John Michael is a self-help writer and a hobby gardener. Michael’s passion in writing is to inspire the beginner gardeners to not just “hang in there” or “make it through” but to thrive. He does this through blogging.

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