Gardening in the city improves air quality and reduces overall heat. Lack of space and the high cost of land, though, is often a dilemma.
This is where rooftop gardens come into the picture. But what are some problems with rooftop gardens?
Seven Problems & Solutions: Water Supply (rain barrels), Drainage Issues (build drainage system), Weight of Rooftop Garden (plastic planters), Getting your supplies to the rooftop (elevator & build shelves on the roof), Exposure of plants to sun and wind (position of plants and low walls), and Plant Selection (choose heat & drought tolerant – low growing succulents).
The environment in cities is getting worst. Concrete structures have taken over green spaces. The lack of green spaces has caused city dwellers to deal with the urban heat phenomenon, as well as noise and air pollution.
Rooftop gardens are increasing in popularity, especially in more developed and larger cities.
Creating a rooftop garden allows you to ignore the city below and instead enjoy watching butterflies surround your blooms.
Creating a rooftop garden is one of the easiest options to deal with the negative effects of urban development.
What is a Rooftop Garden?
A rooftop garden, as its name suggests, is a garden created on the rooftop of residential and commercial buildings. The garden consists of plants that can help improve the aesthetics of a building.
You can build your rooftop garden on a flat roof surface. You can grow almost anything in your rooftop garden- flowers, shrubs, grasses, vegetables, and even trees. Your rooftop garden may also include outdoor furniture.
Plants that are bottom-heavy instead of top-heavy are the most ideal for rooftop gardens to prevent them from being blow over by high winds.
Avoid large-leaved plants because the wind could easily shred them up.
Before planning your rooftop garden, check the building code in your area or your landlord.
Problems with Rooftop Gardens
While rooftop gardens are beautiful, they can be challenging. Caring for plants in containers on a rooftop is pretty much like caring for container plants on the ground. There are, however, some peculiarities to consider when creating a rooftop garden.
1. Water Supply
Rooftop plants are grown in containers so they will need more frequent watering than plants grown in-ground. The sun, wind, and water will hit your rooftop plants harder, too.
It is important, therefore that water is easily accessible. Is there a faucet on your roof and is it close enough to your plants? Access to water is one of the major problems with rooftop gardens?
Solution: If there is no water source on your rooftop, you can choose to have rain barrels with spigots and attach them to a hose. Well, you can also opt to carry water from the inside of the building to the rooftop. Drip irrigation is also an option.
2. Drainage Issues
Drainage is an important component of a garden especially when you are growing plants in containers. A traditional garden on the ground can drain freely. You will need to keep a close eye on how drainage will work in your rooftop garden.
You need to make sure that water from your rooftop garden does not leak into the building through crevices and wall cracks. You also need to make sure water from your rooftop garden does not drip down the outside of the building.
Solution: Waterproof and build a rooftop garden drainage system. You can install a thin layer of insulation to the rooftop that will allow excess water to flow into a drainage or storage tank system on the ground.
3. Weight of your Rooftop Garden
The weight and structure of your rooftop garden can affect the overall building. Planting pots or containers, the soil, or planting beds are heavy and add to the weight the roof structure needs to carry.
Solution: Determine the load capacity of your roof. Opt to use a lightweight growing medium. Bagged soils or container mixes contain perlite, sphagnum, and vermiculite which retain moisture, provide aeration and weigh less than garden soil.
Use lightweight wooden or plastic pots and planters instead of concrete or terra-cotta ones that are heavier.
You can also make your planters out of plastic buckets, children’s wading pools, and recycling bins. Just make sure to drill holes on the bottom of these containers for drainage. Vertical trellises are also a good option.
4. Getting your Gardening Supplies to the Rooftop
How are you going to get your garden supplies in and out of the rooftop?
Solution: Make sure you are allowed to use the elevator to bring your gardening supplies to the rooftop. Start with smaller plants you can carry. Buy knockdown shelving units, trellises, and planters that can be assembled on the rooftop.
5. Exposure of your Plants to the Sun
Your plants will have little protection from the elements. The sun and wind can be cruel to plants grown on the roof.
Most roofs get full sun or more than six hours per day of direct sunlight. Ambient heat is also reflected from the surface of the roof.
Solution: Grow plants that thrive in full sun. If you are growing plants that love the shade, position your garden on the portion of the roof where the nearby buildings can provide shade to your plants for most of the day.
A low wall can help protect your shorter plants from the strong wind. As for taller plants, they may need to be staked so they can withstand strong winds.
You can also install features that can provide some shade for your plants.
6. Exposure of your Plants to the Wind
It can be extremely windy on the rooftop especially if it does not get any shield from neighboring buildings. Your plants may get toppled by the strong winds.
Solution: Install windbreaks such as a structure to shelter your plants (a trellis) or some fencing. You can also avoid vase-shaped containers and top-heavy containers.
Use square planters instead and place them against a windbreak.
Long-stemmed flowers will be blown off by the wind unless they are staked or sheltered, so it is a better idea to grow low-growing flowers and shrubs.
Lightweight outdoor furniture and gardening tools and materials are also liable to be blown away in windy weather, so ensure that they are completely secure.
7. Plant Selection
Selecting plants to grow in your rooftop garden can be fun and challenging. You should take into consideration their water and light requirements. They should also be able to withstand the windy conditions on your rooftop.
Solution: Choose plants that are tolerant to heat and drought. These plants are also most likely to grow and thrive in dry and windy rooftop conditions. You can plant those that grow well in containers.
You can also plant low-growing succulents. Stay away, though, from trees that require extensive space for their root system.
It is a wise idea to go for species native to your area and are drought tolerant. Native plants attract local wildlife.
This can make your rooftop container garden habitat for songbirds, butterflies, and other local birds and pollinators.
Rooftop gardens provide breath-taking views. They offer beautiful scenery even if they are about 30 feet above the ground.
Green roofs provide the solution for city dwellers who want to have a garden but do not have the space for it.
Having a rooftop garden has many advantages to buildings and the environment. It may seem to entail a lot of work and a huge investment, not to mention some problems with rooftop gardens that you must deal with.
But the benefits of having a rooftop garden outweigh all the challenges.
When your rooftop garden has been completed, you will realize that it is worth having a space in the middle of the city to enjoy some beauty, freshness, calm, and relaxation.
If you’re thinking of doing it then start soonest and enjoy all the benefit it brings – it’s a great de-stressor!