Designing the Space.
No matter how large or small the garden, all of the plant’s needs must be met. The gardener’s duty is to provide his/her dependents with light, water, carbon dioxide (CO2), nutrients, temperature and humidity.
You may want to grow but you don’t think that you have enough space. However, even a tiny space such as a small closet, shelf, armoire or portable container can be converted into a garden.
As an example we will describe the conversion of a closet space to a garden. The closet space has an area of 40" x 22"(100 x 55 cm). It is 80" (2 m) high, divided into an upper and lower space. Each level is 880 sq in, divided by 144 sq in, it equals about six sq ft (0.55 sq m). We will be using only the bottom shelf.
If the space were to be kept at a high temperature (80°+ F) (27°+ C) and was enriched with CO2 it would be able to use the brightest light, 60 watts per sq ft (650 watts per sq m) This garden space is kept at a lower temperature. CO2 is supplied by exchange with the air in the room. Under these circumstances the plants are not able to use all the light emitted because both temperature and CO2 would be limiting factors.
The garden temperature will stay in the mid- to high-70s (25° C) and the CO2 will be kept close to atmospheric levels of about 380 ppm. Height is also a limitation to be taken into account.
Instead, the top level of the garden will be lit using a 200w LED.
Other good choices for lighting the garden are 250w MH and HPS lamps. They emit about 20,000 and 26,000 lm, respectively. However, without proper ventilation they might create heat problems.