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Gardening glossary

Fenestration

Fenestration ("fenestra" means window in Latin) describes the splits, slits, and holes in the leaves of Monstera deliciosa, Monstera adansonii, some Philodendrons, and a few other tropical aroids. Juvenile leaves on these plants are solid hearts; as the plant matures and starts climbing, new leaves emerge already fenestrated and the splits get larger and more numerous with each new leaf.

There are two competing scientific theories for why these plants evolved fenestration:

1. **Light gap theory.** Holes let dappled jungle light reach lower leaves on the same vine, increasing the total light captured by the plant. 2. **Wind and rain theory.** Splits let tropical storms pass through the leaf without tearing it off the stem, since these vines climb 60+ feet up rainforest trees.

In cultivation, three things drive fenestration:

- **Maturity.** A Monstera deliciosa typically doesn't fenestrate until it's produced 4–6 leaves and has a stem thick enough to support climbing. Patience matters. - **Light.** Brighter indirect light (close to a north or east window, or filtered south/west) produces dramatically more fenestrations than a dim corner. A plant in low light will revert to solid juvenile leaves. - **Climbing support.** Aroids are vines. Give them a moss pole, coir pole, or wood plank to climb and the next leaf almost always comes in larger and more split than the last. Plants left to trail off a shelf produce smaller, less-fenestrated leaves indefinitely.

If your Monstera's new leaves are smaller and less split than older leaves, something has regressed — usually light or the plant outgrew its pot. Brighter light, fresh potting mix, and a sturdy climbing pole usually trigger a return to bigger, holier leaves.

Note: damage holes from pests or accidents are not fenestration. Real fenestration is symmetrical and present when the leaf unfurls.

Where this comes up in our guides

Related terms

Node

A node is the joint on a plant stem where leaves, buds, and roots emerge. The space between two nodes is called an internode. Nodes are the single most important feature when taking cuttings — no node, no roots.

Propagation

Propagation is creating new plants from an existing one — through cuttings, division, layering, or seed. Most houseplants propagate easily from stem cuttings rooted in water or soil, making it the cheapest way to grow your collection.

Photosynthesis

Photosynthesis is the process where plants use light energy, water, and carbon dioxide to produce sugars and oxygen inside their chloroplasts. It powers virtually all plant growth and underpins almost every other gardening decision you make.