SummaryThree varieties of roselle, dark red, red and green, were studied over 2 years for yield and susceptibility to insect attack at three population densities and five NPK fertiliser rates. The three population densities, 17,777, 26,666 and 53,333 plants ha–1, and five NPK (20-10-10) fertiliser rates, 0, 50, 100, 150 and 200 kg ha–1, were arranged in a split-split plot fitted into a randomised complete block design with three replicates. Data were collected on major insect pests, and their damage, as well as on growth characters such as plant height, number of branches, total biomass, calyx fresh and dry yields and seed yield. In both years, only the populations of Podagrica spp., Oxycarenus spp. and Apion spp. were influenced by roselle variety. Their populations and damage were significantly higher (P < 0.05) on dark red and red varieties than on the green variety. The three roselle varieties showed no significant positive response to NPK fertilisation, even at the highest fertiliser rate. Similarly, susceptibility of roselle to insect attack was not significantly affected by NPK fertilisation. However, significant variations, jointly influenced by variety and plant density, were observed in growth characteristics. While the dark red variety that suffered the most severe insect attack produced the lowest yields, the red variety, which was moderately attacked, was significantly taller (P < 0.05) and produced more seed yield compared with the other varieties. Optimum population densities of 26,666 plants ha–1 (75 cm 50 cm spacing) and 53,333 plants ha–1 (75 cm 25 cm) were established for maximum yields of the green and red varieties, respectively; while NPK appeared not to be a major requirement for the production of roselle in the sub-humid zone.