Nothing predetermines a plant’s stature like its genetic heritage. Indica varieties tend to be short and bushy so they are appealing for indoor growth. Unfortunately, Indicas also tend to be more difficult to grow and are usually a low yielder in comparison to the sativa varieties.
On the other hand, a pure Sativa can easily become a nightmare for indoor growth due to their height and aggressive vegetative growth. Keeping a pure sativa’s internodal spacing tight for indoor growth is close to impossible.
I recommend finding a good hybrid with a little more indica than sativa. A 60/40 hybrid is great for indoor and outdoor growth and will give you the shorter stature of the india and the higher yields of the sativa. Choosing the right hybrid can make your garden much more productive and can make the gardener’s job a lot easier.
Proper light intensity will ensure your plant’s internodal spacing stays in check. If a plant is receiving inadequate lighting it will “stretch” for the light and produce elongated internodal spacing. Keep the light as close to the plant as possible (without burning it) to reduce the plant’s need to “stretch.”
The use of T5 florescent lighting in the vegetative stage can help achieve a tight internodal spacing as well. Because the florescent lights are much cooler than their HID counterparts it is possible to practically touch the plant canopy with the bulbs. This extremely close lighting technique will cause tight branching patterns and is my favorite method for creating short bushy plants.
Adding certain kelp formulas rich in auxins like Nitrozyme can help keep plant growth bushy. Using a bloom initiation product like Bud Blood or Bud Igniter can limit the “stretching” marijuana plants do during the first few weeks of the blooming phase and can help keep the internodal spacing tighter.
Topping and super-cropping are a couple of methods used to create bushy plants with tight internodal spacing. Topping or pruning your plants is a method of physically cutting the plant. Topping refers to cutting the very top growth of the plant just above the next set of branches. The plant will then multiply with new growth, where there was one branch there will now be two. When repeated multiple times, this method produces an extremely bushy plant with many more flower sites than an un-topped plant.
Super-cropping is a term for pinching or bending the central stem of the plant. This causes the lower growth to “catch up” with the central growth and causes a bushy effect on the plant allowing for more flower sites to form in the upper section of the plant canopy.
Experimentation with different genetics, lighting techniques, nutrient additives and manipulation methods will help you create the perfect plant canopy with tight internodal spacing. Don’t be afraid to try different combinations of methods until you find your niche. Just remember, the more buds on top, the more weed you got.