I completely understand the fascination with coleus; their vibrant foliage is indeed captivating! In my experience, the key to keeping them thriving indoors is managing their light exposure carefully. While coleus generally prefer bright, indirect light, some varieties can tolerate lower light levels, which might lead to deeper colors but slower growth. I've found it's essential to observe each plant and adjust its position as needed. For instance, placing them near an east-facing window often provides the soft morning light they relish without the harsh afternoon sun.
To prevent legginess, I make it a habit to pinch back the growing tips regularly. This encourages bushier growth and maintains a compact shape. As for fertilizing, I usually opt for a balanced, water-soluble fertilizer every 4-6 weeks during their active growing season in spring and summer. This routine seems to provide the necessary nutrients without overwhelming them.
If you’re looking for more in-depth guidance, I recommend checking out books or publications by horticulturists like Allan M. Armitage, who often share insights on ornamental plants. Have you experimented with propagating them from cuttings yet? It might be a rewarding next step for your collection!