Ask Ed: Grow Questions and Answers – Pruning Underbrush

CANNABIS CULTURE – Ganja Guru Ed Rosenthal on how to trim underbrush to increase yield without hurting your plants.

Question: I have an aeroponic system and am using the “sea of green” method. I have a huge canopy, but the plants are tall. I want to trim underneath the canopy so the buds can receive more light. How much can I trim without hurting or affecting the buds of the plants?

T.B., Internet

Ed Rosenthal: Most of the yield of buds is going to be harvested from the top of the canopy, where the light is most intense. This should be the main area of the plant that is pampered.

Once light hits a bud, leaf or any non-reflective surface, its energy is absorbed. For this reason light can penetrate only 10-12 inches into the canopy. If the canopy is filled with vegetation, any vegetation beneath that area is in shadow and is not expected to yield very much.

There are techniques to increase yield in this situation: first, remove any fan leaves that are blocking light getting to buds. Don’t pick fan leaves that are not blocking light because they are factories converting light to sugars, which the plants use for energy and growth.

If there is open space in the canopy, tie, bend, or stake branches so that they occupy the area.
Remove understory underdeveloped branches, leaves and small flowers. They are wasting the plant’s energy that will be better used in the action areas.

Another technique is to supply side lighting to the understory using either fluorescents or HPS lamps. Fluorescent tubes or compact fluorescents (CFLs) can be placed around or even inside the garden, and sometimes between the plants to light the lower buds.

Harvest the garden in stages. Sometimes only the top portion of the bud is mature. Harvest the ripe part, but let the lower portion stay on the plant for a few more days. As the lower portion of the bud matures, the top portion of the understory, below the bud where the medium sized but immature buds are, starts to receive more light and responds with additional growth and maturation. Within three to five days the lower bud matures and is harvested. This leaves the understory completely exposed to light. It will mature in another five to seven days.

Send your grow questions to Ed Rosenthal at [email protected].