The design of the Greenhouse garden supports the overall philosophy, in providing the visitor experiential learning. Knowledge is shared with the visitor by providing a functional garden for the Greenhouse kitchen use, while noting an ever changing display of horticultural variation that highlights the gardens normal seasonal growth. Visitors will also be able to observe the garden’s occasional adjustment required to support seasonal and climatic changes. Where possible, recycled materials have been used, for example, Schutz ecobulk containers and crushed Styrofoam. Additionally, companion and non-competing planting has been introduced as a natural form of sustainable growing and therefore limiting the need for artificial pesticides.
Key aspects of Horticultural overlay include:
• Recycled Schutz ecobulk containers.
• Planting medium to consist of three (3) layers:
1. 100 mm coarse sand;
2. 210 mm crushed Styrofoam; and
3. 400 mm potting mix blend – 75% composted pine bark and 25% coarse sand.
• Containers planted with combination of seasonal annual, and perennial, herbs and seasonal vegetables.
• Containers are irrigated via a drip irrigation system. All drainage water is collected then transferred to holding tanks for reuse as further irrigation.
• Coarse sand in base of container acts as filtration system for excess (drained) irrigation water.
• Due to low direct sun, portable grow lights are positioned above planted containers as the season and plant variety dictates.
Lower Planter boxes
• Planter boxes are filled with potting mix blend comprising 75% composted pine bark and 25% coarse sand.
• Planters are planted with a combination of Laurus nobilis (Bay tree) and Citrus x hystrix (Kafir lime leaf).
• Automated drip line irrigation system are installed to planters.
Both Laurus nobilis (Bay tree) and Citrus x hystrix (Kaffir lime leaf) are to be maintained at a height of 1.8m and 1.5m respectively. This will be achieved to maximize the fresh leaf growth for use in the restaurant kitchens. Both species are “evergreen” and have aromatic foliage. The Laurus has a deep green, glossy, leathery foliage. The Citrus has a softer green leaf and produces a rough, bumpy green fruit.
Image 1: Laurus nobilis (Bay tree)
Image 2:Citrus x hystrix (Kaffir lime leaf)
• Exterior of building is clad with galvanized planter frame (steel reinforcing mesh)
• 125mm terracotta pots planted with fragaria alexandria (strawberry) and miniature ivy to be placed at 200mm spacing (25 per m2)
• Drip irrigation installed in the top row of planters with water feeding down each pot. Excess water is collected at the base of planter and transferred to the holding tank for reuse.
A number of companion planting combinations have been developed as a kitchen garden for sustainable growth on the greenhouse roof deck.
Every living entity requires ongoing maintenance to preserve the functionality and aesthetic appearance in an ever changing environment. The maintenance program continues to support the educational aspect of the Greenhouse, while retaining the functional aspect of the kitchen needs with the aesthetic design of a welcoming place to meet and socialise.
Given that the majority of the plants grown on the roof deck will be harvested and used in the restaurant kitchen, required pruning will be minimal. Varieties such as the espaliered fruit and citrus trees will need seasonal pruning to maintain shape and size. Annual herbs and vegetables will need to be replanted as the seasons dictate. Fertilization of the planters will be carried out on a seasonal basis with most fertilizing performed when annual herbs and vegetables are replanted. It is recommended an organic blood and bone blended fertilizer be used for seasonal fertilization. A seaweed based liquid fertilizer may also be applied to leaf crop herbs and vegetables such as basil, spinach, lettuce etc.
A fully automated drip irrigation system runs to all roof deck planters, lower planter boxes and vertical strawberry and ivy pots. Drained water is collected and transferred to a holding tank for reuse. It is anticipated the fully automated drip irrigation system will use approximately 620 litres of water per day in peak season (eg. summer) and 65 – 70% of this daily use can be reclaimed in utilizing the holding tank facility. This results in a net daily water use of 186 – 217 litres.
At an appropriately selected time, seasonal replanting will take place to update a number of the seasonal vegetables and herbs with suitable cold climate varieties such as the brassica family of cauliflower, bok choy, cabbage, brussels sprouts.