Best beginners guide to grow vegetables on rooftop garden

Vegetable gardening on the roof is a smart choice for the urban gardeners and a proper planning before you start will make the job easier for you.  In this article, you’ll get step by step instructions to complete your rooftop vegetable garden.

As a roof gardener, you have some benefits and also face some challenges. It brings you an opportunity to get some fresh food, make some exercise and fulfill your hobby. On the other hand, a ground level or a backyard gardener also get some benefits and face some challenges as usual, because of not being a roof gardener.

So, it is vice versa.

Typically, around a 700 sq. ft. vegetable garden can supply the demand of a family of six members all the year round.

Isn’t it pretty interesting! YES, and you have also some hidden benefits, you couldn’t feel before you start.

 Rooftop Vegetable Garden

Step-1: Things to be considered before starting a rooftop garden

How to start a roof garden depends on some issues like available unused space on your roof, have permission to use the roof as garden, following the local municipality law or garden law or homeowners association law.

Then, you must need to consult with an engineer to check the load capacity of your building roof.

Besides, observing the surrounding environment of your building is really important.

You need a little bit research about the sunlight exposure and wind flow over the roof, in order to take necessary steps to prepare the garden design.

You must consider the water supply sources and drainage system for garden on the roof.

After considering the above issues you can go to your next step.


 Step-2: Methods of building a rooftop vegetable garden

After considering the preliminary issues of starting a roof garden, you have to give concentration on the construction methods you follow for your roof garden. You can build a roof garden in three different ways like:

  • Container gardening
  • Raised bed gardening
  • Regular landscaping gardening (covering all over the roof or selective part of a roof as a ground level garden).

Container method 

When you have a limited or very little space, you can still have a vegetable garden. In this context, container gardening is the best choice for you.

You can design your vegetable garden vertically using plastic bottles hanging on the wall, or arranging broad PVC pipe, creating holes and filling with potting soil on it and placing them in a multi-story frame structure.

Besides, you can use a reasonable height shelf, placing multiple containers on it. But always keep in mind the load capacity of your building roof, available water supply, and proper drainage system.

If you have a limited budget, use old unused plastic containers, drums, wooden box, heavy-duty black color poly bags, wastage bin, unused kid’s bathtub, old kitchen utensils or other things which can contain soil for plants as a garden container. Make the necessary holes at the bottom of each container according to the size of the container for the drainage system.

Always keep a tray at the bottom of each container or structure to hold water, used for irrigation of the garden plants. It will protect your building roof from damage and keep it dry.

Usually, you can cultivate all types of vegetables in a container, but choose the vegetable varieties better grow in containers. When you buy seed from the seed market, check out the seed packet confirming that the varieties applicable for containers or not.

Raised bed method

Making a raised bed vegetable garden on the roof is more flexible than a container based garden. Here you get enough room to decorate your garden the way you want it. But the making process of a raised bed garden on the roof is a little bit different from a conventionally raised bed garden.

You don’t need to think about load capacity and water leakage when building a conventional ground level raised bed. But, you must need extra protection, when creating a raised bed on the roof.

Step 1

  • Determine the size and shape of the raised bed, and measure the length and width of the overall garden area.
  • Choose the right materials and make a decent layout design with the specification of your raised bed vegetable garden. The wooden structure is the most commonly used materials for the raised bed garden.
  • And of course, you must avoid the heavyweight materials, when you design for a rooftop garden.

Step 2

  • Follow the layout design and the specifications you choose to apply for your raised bed garden.
  • Determine the height-length-width-depth of the frame of your raised bed, according to the minimum requirement of space and depth needed for the plants you want to grow in the bed.
  • Usually, the average minimum height of a raised bed shouldn’t be lower than 6 inches, but 12 inches is standard and higher is better.
  • Your raised bed length and width should be flexible sized if you want to change the design in future. This simple trick can help you to change the design easily without changing the frame structure of the beds.
  • As for example, if you make a bed, which is 12 feet long and 6 feet wide, then don’t make a full-length single frame as the requirement. You better divide it into 3’/6’ or 3’/3’ or 3’/4’ feet frame. This simple trick will ultimately give you the same size when you put them together, moreover, you can turn them into a new shape, if
  • Besides, keep a certain space for the walkway in between two beds in your layout design. This trick will help you to move from one bed to another for nurturing the plants, irrigation, and other purposes.

Step 3

  • Setting up the plastic tray on your roof to confirm that, water doesn’t seep into your roof, then place the raised bed frame on it.
  • You can also install the planters frame on a low height flat stand or on a deck, to protect your roof from seeping water.
  • After placing the raised bed frame on a tray or deck, staple up a chicken wire at the bottom of the frame. Then, put on a weed cloth or landscaping fabric on top of the chicken wire and fill up the bed with potting soil with compost mix and other necessary components.
  • For more flexibility, you can place your whole raised bed on a rolling frame for easy moving.


Method for constructing regular landscaping garden on the roof:

Landscaping garden on the roof is more challenging and expensive than the previous two methods because it covers the roof as a ground level garden. You can easily start a container gardening or raised bed gardening, consulting with an engineer, but the expert hand is not essential all the time.

But, you must need experts support to construct a landscaping garden on the roof. To create a landscaping garden you need to ensure the following technical steps, which you can’t do by yourself.

Step 1- Waterproofing: This is the most essential part of roof gardening construction, no matter you grow plants on the container or raised bed. But, landscaping waterproofing is expensive than others.

Waterproofing layer protects all over the roof from seeping water and resists unwanted damage.

Step 2- Insulation: This layer controls the temperature fluctuation and resists moisture leaks. It makes stronger the overall structure. Fiberglass, mineral wool, polyurethane foam, and polystyrene are most commonly used for insulation process.

Step 3- Drainage system: Drainage layer helps to release the rainwater easily from the soil bed.

Step 4-Landscaping fabric: This layer filtering the water to come out from the soil layer through drainage layer. It also protects the drainage layer from clogging soil and other particles from the upper layer.

Step 5- Soil layer: This is the layer where you’ll grow plants. Fill up your garden area with potting soil, compost, and other essential particles and make it water permeable. The depth of the soil layer depends on the plants you want to grow on it.


Step-3: How to choose the right container for your rooftop garden

Selecting the right planter for your vegetable garden depends on your situation, demand and others factors. Here I explain the major factors, influence to select the right planters.

Container for rooftop garden

Plants type:

This is the most important factor, helps to choose the right planter. Different plants have different shape and size and they need different space to grow. And so, choosing the right planter mainly depends on the plants you want to grow in your garden.

It’s also very true that you never going to grow the same plant all the time. In that case, you better choose a standard size of the planter, which is capable to support the vegetables and herbs you want to grow.

Typically, half-gallon container to five-gallon container is common sizes to grow most of the plants.


Plastic containers are lighter than other containers. They are suitable for roof garden or wall decoration or hanging on your balcony. They look pretty simple and keep moisten the potting soil for a long time. Moreover, they are cheaper than the terra-cotta or ceramics containers.

On the other hand, terra-cotta, ceramics or clay containers are expensive. They are very lucrative but heavier than the plastic containers. Besides, the potting soil dry sooner in terra-cotta containers, so you need to water the plants regularly and take more care.


If you are budget conscious, pick the plastic containers for your garden or unused household material which can contain potting soil for your plants.

On the other hand, if you mainly focus on the design of your garden, pick the terra-cotta or ceramics containers or whatever you wish.

Load capacity:

Load capacity is another variable, influences deciding garden planters. Usually, lightweight planters are best for a rooftop garden, and so, avoid heavy weight planters like terra-cotta or clay planters.


If your rooftop has a shortage of space, it can also persuade of selecting planters to manage your limited spaces with proper planter’s design.

Step- 4: Considering the growing medium

Preparing soil for your roof garden is different from the conventional garden. Soil mix for your rooftop garden must be lighter than a regular soil mix, but only lightweight soil can’t solve all the issues. There have some other factors to be considered.

If your garden area receives enough rainwater during the growing season and the average rainfall ratio is higher, you would need a soil mix that dries out quickly. But if you have an area receive less rainwater and humidity, try to use a soil mix that holds water for a long time.

Besides your plant selection also influence to choose the right growing medium. Some plants need less water and some plants need more water than average.

So, you must keep in mind the weather condition in your garden area, the type of plants and of course, the lightweight potting soil when thinking of a roof terrace gardening.


Steps- 5: Watering your plants

The irrigation system is one of the important parts of gardening. Urban people lead a busy life and sometimes it is hard to manage regular nurturing and watering the garden plants. But you can’t skip out this part anyway.

  • Drip irrigation system is the most effective system for watering your rooftop garden plants. This is an expensive system comparing other irrigation systems which need regular maintenance. It has an auto controlling system and timer which can save water and protect your plants from damage.
  • Sprinkler irrigation systems are not very effective, particularly for roof gardening if you plan for a container garden. Besides, this system wastes some water and evaporate quickly in dry season. Best suit for lawn garden and raised bed.
  • The plastic bottle drip irrigation system is the most cost-effective and easy watering system than others. It provides the similar support like the drip irrigation system but you have to control it manually and no option for setting a timer.
  • Traditional irrigation system needs labor regularly. You can use watering cans if you have a small garden or use hoes pipe for irrigation your roof garden.

Timing is another vital factor of watering your garden. You must have to maintain a schedule for watering your garden. First three hours after sunrise and last three hours before sunset it the perfect time for irrigation. Always keep in mind, never watering your garden plants in the middle of the day and after the evening.


Steps- 6: Vegetable plants diseases and pests problems

It is natural that plants got diseases. There are plenty of ways your garden plants become infected or attacked by pests.

Pests can harm vegetable leaves and reduce your production and sometimes destroy the whole crops. Your vegetable garden fruits can also be affected by pest and bugs. When you notice any symptom of diseases, immediately get rid of the infected leaves and fruits and apply organic pesticides if required.

Sometimes your garden plants become weaker and turn gray due to lack of nutrients, soil condition, irrigation, and proper care.

Fungal diseases and viruses are other challenges for your vegetable plants which can destroy your yield.


Steps-7: How to choose vegetables and herbs for your roof garden

You can grow whatever you wish in your garden, but you must take into account some major factors before growing any plants in your garden to reduce the risk of failure.

  • Weather Requirements: You must be well concerned about the microclimate in your garden area as well as the plants you choose to grow. Do the selected plants sun-lovers or shade-lovers? Do they grow well in cold weather or hot weather?
  • Container size: Most of the vegetables and herbs need ½ gallon container to 5-gallon container to grow better. You need to gather some knowledge which container size best suit the plants you are going to grow.
  • Soil depth requirements: Select your vegetable plants and herbs based on the depth of your garden container and raised bed. Or, collect some containers based on the plants you wish to grow.
  • Best time to grow: Every plant has a growing season. When you choose the plants keep in mind the growing season of each plant. Perfect planting time will give you a better result.
  • Special care: Some plants need less care and some need more. Proper fertilization and irrigation will give you the best result. Besides, arrange climbing aid when the plants demand.
  • Suitable varieties: Some vegetables have some special varieties which grow well in a container or raised bed. Find those varieties in the seed market and always follow the seed packet instructions for suitable varieties.
  • Good Companions: To make the best utilization of your garden space you can grow two or more friendly vegetables and herbs at a time. First of all, select the plants you want to grow in the garden and then select, which vegetables grow well together with your selected plants?
  • Bad Companions: Some vegetables don’t grow together and hamper the normal growth and harvest of your main crops. So, you should select carefully the companion plants for your garden.

Does roof vegetable gardening really save money?

Starting a vegetable garden on the roof is very common, but when the question arises “does it really save Money?” here needs an explanation to answer the question clearly.

Technically speaking, the answer is yes!!! But the following factors influence to calculate your account accurately.

Gardening Save Money

Monetary Factors:

These factors help to calculate the return of investment in your garden and how much money you can save.

Need-based production:

You must produce something you really need for your family and they like to eat. Don’t invest your money in something which is not necessary.

Produce something expensive:

No matter what you produce you need time, labor and money. So, produce something expensive which can help you to curtain your grocery budget.

Produce something that can preserve:

You can’t consume all of your garden production at a time if you get a bulk production. So, produce something that can be canning, freezing or preserving other ways.

Start small:

Roof garden needs some extra costing for waterproofing and drainage system. So start on a small scale to realize the real scenario and hidden facts to avoid the risk of failure.

Minimize your costing:

For your roof garden choose some unused lightweight household materials, growing from seeds instead of seedlings and use homemade compost to minimize costing.

Calculate time, labor and investment:

This is really important to calculate your time, labor and investment to find out how much money you can save from your garden.

First of all, calculate how much time you spend over the year multiplied by per hour minimum value of your time. Also include the cost of seeds, fertilizer, garden tools and other costs to count the total investment.

Then, measure your season end produce multiplies by per pound value of your production to count the total production.

Finally, exclude the total investment value from the total productions value to get the return of your investment.

Non-monetary factors:

Gardening also have some hidden benefits which you cannot measure by money. You can only feel it to measure its value.

  • Health benefits: Gardening is a great natural exercise. Besides, it kills your loneliness and makes your mode better. Moreover, this is a great source of vitamin D.
  • Fresh grown food: Gardening creates an opportunity to have some chemical free fresh food.
  • Tasty food: Homegrown vegetables and fruits are tastier than the fruits of the grocery store.
  • Create a private place: Gardening gives you a private place to spend some time of your own.
  • Create a food habit: Gardening attracts your kids to take homegrown fruits and vegetables as well as inspire them to do it.


Reading this conclusion proves that you are very serious about starting a garden. Make a simple plan, do some research and go for it. Don’t over thinking of it. As a beginner, gardening has no loss if you don’t start it commercially.

You will learn so many things after staring at your garden which I don’t mention it here. The actual fact is nobody can tell you accurately. You must have to start to know the insights of gardening. So, you better start today.

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.

One thought on “Best beginners guide to grow vegetables on rooftop garden

  1. Hi John Michael
    I am just about to start a roof-top vegetables garden and I happened to find your detailed write-up. It was a fantastic reading and will surely help me in finding way through my journey ahead. Please keep it up. Wish you best. Cheers

Leave a Reply

Your email address will not be published.