From my perspective as a Greek oregano plant, the most common reason I become leggy is a simple, desperate need for more sunlight. I am a Mediterranean herb, evolved to thrive under the intense, direct sun of that region. My very essence is programmed for high light levels. When I am placed in a location that receives less than 6-8 hours of direct, unfiltered sunlight per day, my survival instincts kick in. I must find the light to photosynthesize and survive. I will begin to rapidly grow my stems longer and stretch towards the nearest light source. This rapid, elongated growth comes at a cost. My stems become thin and weak (spindly), and the spaces between my leaf sets (internodes) become abnormally long. I am not trying to be unattractive; I am simply fighting for my life by reaching for the energy I need to exist.
Your pruning habits, or lack thereof, directly shape my growth form. If you only harvest my topmost leaves or rarely trim me back, I have no incentive to become bushy. I will simply continue growing upwards on a single, central stem. To encourage me to fill out, you need to signal to my growth nodes that it is time to branch out. The most effective way to do this is by pinching or trimming the tips of my stems. When you remove the apical meristem (the primary growing tip), you disrupt the production of auxins, hormones that suppress the growth of lateral buds. With this suppression lifted, the buds lower down on my stem are activated and will produce two new branches. Regularly doing this throughout the growing season forces me to grow denser and wider instead of just taller, creating a much more compact and productive plant.
While nutrients are important, too much of a good thing can be detrimental to my form. If the soil I am growing in is too rich, particularly in nitrogen, it can force an overabundance of soft, green, vegetative growth. Nitrogen encourages rapid stem and leaf development. An excess can cause this growth to be weak and overly rapid, leading to a leggy structure rather than a sturdy, compact one. I am adapted to relatively poor, rocky, well-draining soils. A constant surplus of nutrients, especially nitrogen, is unnatural for me and pushes my growth in an unsustainable direction, making me top-heavy and fragile.
It is also part of my natural life cycle for the base of my stems to become woody over time. This is a normal process of maturation where soft, green stems develop tougher, bark-like tissue to support the plant's structure. However, as this happens, the woody parts often lose their ability to produce new leaves. The leafy growth is then concentrated at the ends of the stems, which can give me a leggy appearance with bare "legs" at the base. While this is partially inevitable, it can be managed through the pruning techniques mentioned earlier and by periodically propagating new, young plants from cuttings to replace older, woodier specimens.
To fix my leggy predicament, you must address these core issues. Immediately move me to the sunniest possible location, such as a south-facing window or, better yet, outdoors. Give me a hard pruning, cutting my stems back by up to one-half to two-thirds of their length, making your cuts just above a set of healthy leaves. This severe haircut is a shock, but it will stimulate new, bushier growth from the base. Begin a consistent pinching routine with any new growth. Ensure I am planted in well-draining soil and hold off on fertilizing; if you must, use a balanced, half-strength fertilizer very sparingly. For severely leggy plants, the best long-term solution is to take 4-6 inch cuttings from the healthiest tips, root them in water or soil, and start a new, compact plant that you can care for correctly from the beginning.
