How do i get dense buds? Mine look really good until I dry them, then they're airy.
There are a number of factors that influence bud density:
1. Genetics
Some plants just don't produce dense buds.
2. Harvest timing
When a plant is fully ripened, the calyxes are swelled up (parthenocarpy), so the buds are denser. Buds harvested prematurely haven't done this, and the dried buds will be more airy.
3. Light intensity
"If you want the density, provide the intensity." Buds grown in relatively low light conditions will be looser than buds grown in high light intensity.
4. High temperatures/high temperature differentials.
Excessive heat, or a big swing between day and night temperature can promote streching and loose buds. Keeping the high temperature below 80F and the difference between high and low between 10 and 15 degrees will help promote tighter buds.
5. Nutrient ratios
Nice tight buds require a high ratio of K to N. Too little K and too much N can lead to looser buds.