Guide to Beginners

About

Terrace garden is any garden on the roof of a building. The practice of cultivating food on the rooftop of buildings is sometimes referred to as rooftop farming. Rooftop farming is usually done using green roof, hydroponics, aeroponics or air-dynaponics systems or container gardens.

Benefits

• Reduces heat in the building
• Generating more fresh air
• Capture and harvest rain water
• Reduce energy costs
• Create habitat for wild life
• Increased physical activity leading to physical fitness
• Growing your own vegetables and less dependency on inorganic stuff 
• Provides self satisfaction

Types of garden

• Green roof gardening
• Extensive
• Intensive
• Container gardening

Green roof

Growing medium is roof. There are two types of green roof. Intensive roofs - thicker and can support a wider variety of plants but are heavier and require more maintenance. Extensive roofs - covered in a light layer of vegetation and are lighter than an intensive green roof. Setting up of green roof requires extensive investment. The building needs additional structural support for soil mass and vegetation.

Container gardening

Container gardening is the practice of growing plants exclusively in containers instead of planting them in the ground. Containers range from simple plastic or terracota pots, teacups to complex automatic-watering irrigation systems. Advantages of container gardening are:

• Less risk of soil-borne disease
• Virtually eliminate weed problems
• Mobile plants gives more control over moisture, sunlight and temperature

Before you begin

Before setting up garden on your terrace, feasibility study has to be done on your roof. Check the following:

Supporting weight - Check whether the roof will be able to withstand the weight which you plan to add over a period of time. If required use construction specialist to find out how much weight your roof could withstand and accordingly plan the number of plants.

Proper drainage - Drainage is very critical, so that water doesn't enter into the roof and damage the roof. Check whether all water moves out of roof through drainage pipes. Check whether there are any blocks in the drainage pipes.

Water proofing - It is advisable to do water proofing on the roof which will avoid water entering into the roof. There are various solutions available for water proofing which includes bitumen based membranes, reinforced acrylic waterproof coating, etc. Based on cost the solution could be decided which will protect your roof and improves the life of your building.

Sufficient sunlight - Ensure that the terrace has sufficient sunlight as most of the plants require atleast 6-8 hours of direct sunlight for better growth and yield. Please avoid setting up garden if there is no direct sunlight on your terrace.

Choosing right plants - While identifying plants for your garden, do have a mix of flowering and vegetable plants. Flowering plants will help you to attract beneficial insects like honey bees, which help in pollination. Also some flowers attract other insects like ladybugs, green lacewings, assassin bugs which helps in controlling other pests. Identify plants that could grow in the climate where you live. In India, most of the vegetables like okra, brinjal (egg plant), radish, flat beans, snake gourd, bitter gourd, ridge gourd could be easily grown. To control pests in vegetables, select companion plants. For example growing basil plants near tomato plants will help to ward off spider mites, aphids and whiteflies.

Selecting containers - We have seen growing flowers in pots or containers but growing vegetables in containers is the latest trend. This saves lot of space and also helps to grow multiple varieties and also maintain them properly. Growing in containers helps to shift to different places based on your convenience. There are 3 types of containers that could be used: terracota pots, plastic containers and grow bags.

Terracota Pots: This is the ideal one as it doesn't get heated up in hot summer and maintains the moisture in soil. There are slightly costly when compared to plastic containers or grow bags.
Plastic Containers: This can be used for growing vegetables like okra which are deep rooted. Since the containers have good amount of depth, it helps vegetables with deep root system. Select containers with light colour as dark coloured one absorbs heat.
Grow bags: Grow bags provides cost effective solution. There are various type of grow bags available and they are UV protected and hence could last long. Average life of grow bag could be around 1 year based on the quality of the bag.

Size of the container should be decided based on the type of plants. Bigger the better to start with, as it will provide good room for the roots to spread. Also ensure that the containers have 2-3 holes at the bottom, so that excess water is drained. If water couldn't be drained then the plant will wilt. 

Watering system - Ensure there is proper supply of water on the terrace for watering the plants. To ease out watering, you can use hose connected to water source. If you are willing to invest further, you can install drip irrigation system which will help in conserving water and also reduce time for watering plants.

Installing green house - Green house helps to protect plants from direct sunlight. This can be used for raising seedlings. Also heat sensitive plants can be grown in green house. A part of terrace can have green house installed. Also if you compost your kitchen waste, then this could be placed within green house.

Installing wind breakers - Wind breakers help to protect plants from strong winds. If your terrace is on 3rd floor and above then wind breakers will be of good use. During cyclone period also this will be of great help.

Preparing containers

• Ensure containers have 2-3 holes in bottom for draining water
• Use containers of light color so that heat is not absorbed
• Size of container should vary based on the type of plant. Small containers restrict growth
• Plants with fibrous root system should have wide mouth containers and plants with deep root system should have narrow and deeper containers 

Potting mix

Potting mix offers three things that a plant needs support (to keep the plant from falling over). It stores water and nutrients for the plant's roots, and still provides good drainage so that the plant doesn't get waterlogged. Provides air circulation so that the roots can get oxygen. Ideal potting mix could consist of 25% black or red soil, 25% sand, 50% compost. Mix them thoroughly and stuff it into the containers. Compost provides necessary nutrients, sand helps in draining water and soil provides good support for the plant.

Coco peat can be mixed instead of sand which provides additional benefits like good water retention, and increased aeration.

Know your pH

Every plant has its own preference for acidity and alkalinity of soil. It is measured as the soil's pH value, and ranges from 0-14. A pH7 value is neutral (preferred by most house plants), a higher number than 7 is alkaline, and a lower number than 7 is acidic. You can find out your soil's pH with a pH Soil Tester.

Watering methods

• Water Deeply so that roots at the bottom get sufficient water
• Check moisture level before watering
• Know your plants and different plants need different level of moisture
• Don't water leaves as wet leaves attract pests
• Water plants in the morning and in evening during summer
• Don't allow the soil to dry which will affect the plant

Seed or seedlings

Best way is to start with seedling. It will be difficult to get seedlings for vegetable plants and best way is to start with seeds. Transplanting seedlings is required for specific type of plants - tomato, egg plant, etc. and for some plants no transplantation is required - all gourd varieties, okra, etc.

Pest control

Pests are the biggest enemies for plants and they will totally destroy the plants or limit their growth. Do not use pesticides against pests as this will lead to other problems. Look at natural way of controlling pests instead of killing pests. To avoid infestation keep the plants healthy. Unhealthy plants gets easily infested with pests. Grow plants that attract beneficial insects and follow companion planting. Growing basil in your garden will help tomatoes. Set up traps for trapping specific pests like flies. Inspect your plants regularly for pest infestation. Some bugs can be easily hand picked and destroyed. Remove plants which are heavily infested, so that you can save other plants. There are various organic pest control methods available which are non toxic and safe to use. Neem oil is one type of organic pest repellent and it can be sprayed on plants to avoid pests.

Types of plants

• Growing different type of plants will help in attracting various pollinators
• Have flowering plants to attract bees and butterflies
• Have herb plants which helps in controlling some type of pests
• Grow vegetables and greens
• Ornamental plants provide better look for your garden

Watch this video for getting inspiration to start terrace gardening:
https://www.youtube.com/watch?v=FBmLZ0zwu88

Happy Gardening!!!