Rebuilding the support for vanilla vines

Raining in February 

The morning began with a walk in the rain from my car to the Conservatory greenhouses - in the month of February. According to the calendar, we should be in the depths of winter. The precipitation today should be snow not rain. The storm system that we're experiencing is probably related to drenching rains moving inland from the west coast.

I met Coordinator A... at the door of the Conservatory. His office desk faces one of the main doors to the building. He cannot escape observing everyone who enters...poor guy, it must be distracting for him. Anyway, as soon as I entered the building we started to discuss his plan for my activity of the morning. He offered me the project of rebuilding the support for vanilla vines which have been suffering from overexposure to sunlight and dry air.

A bit of background

The vanilla plant (Vanilla planifolia) is in the orchid family. It is native to Central America and Mexico. The seed pods were used by the Aztecs to flavor cocoa. It is now rare to find the plant in the wild due to habitat loss and overexploitation.

Vanilla is an evergreen vine that can reach up to 15 meters (50 feet) in length. It has thick segmented stems and yellow flowers. The fruits are long, thin pods that contain thousands of tiny black seeds. The vines have fleshy aerial roots that cling to trees and allow it to climb (ref. Kew Gardens). The vines are adapted to growth in the dappled shade of the forest understory.

The plants are either male or female. The Conservatory has only female plants. So we will get flowers, but they will not be pollinated and will not produce seed pods.

Vanilla blossom

Vanilla blossom

Unhappy vanilla vines

The Conservatory's vanilla vines grow in three different baskets. I suspect there are four different plants, but it is hard to tell because they are so intertwined at the roots. I recall repotting the plant a few years ago, moving it from a smaller plastic pot into a large wooden basket filled with moss. The wooden baskets are specifically designed for orchids and other epiphytic plants. The plant seems to have thrived in the baskets.

About two years ago, the plant was taken out from the shade of a fig tree and moved to a sunny spot, growing up on a glass wall. I recall the plant was moved out of the shade because it had failed to blossom, even though it seemed to grow well in length. Tree branches had been fastened to the wall with wires to add support and a surface for aerial roots to attach. The vines grew well in the sunny location and finally produced flowers. But eventually the vines at the highest point on the wall began to turn from green to yellow indicating stress, probably from overexposure to sunlight.

Vanilla plant growing in an orchid basket

Setting up to rebuild the vine support

The first steps were to remove the vines from the tree branches, then remove the branches from the wall. The metal trellises are slightly more interior, farther from the outside windows. The vanilla vines were then secured to the trellis using metal S-hooks. My instructions were to use coconut fiber fabric to line the backside of a wire trellis. The coconut fabric will be misted every day to provide moisture and evaporative cooling to the vines. The hope is the aerial roots of the vines will latch onto the fiber backing for additional support.

Vines supported on tree branches

Vines supported on trellises, with coconut fiber backing

Final adjustments

I used a ladder and wooden planks to access the metal trellises. The metal S-hooks allow the support to be easily adjusted as the plant grows. I arranged the four main vines on the trellises in a way to suggest natural growth and expansion up and out from the root baskets. Coordinator A.... asked me to keep the vines low enough on the trellises to allow the aerial roots to drop down into the water of the tanks holding other aquatic plants. The moisture of the tanks will help the vines stay hydrated.