How to Sow and Plant Salvia Salvia may be grown from seed sown early indoors and transplanted outside after frost, sown directly in the garden in summer, or grown from potted plants. Sowing Salvia Seeds Indoors · Sow indoors 10-12 weeks before the last frost. · Barely press the seeds into seed starting formula. · Keep the soil evenly moist at 70 degrees F. · Seedlings emerge in 15-21 days. · As soon as seedlings emerge, provide plenty of light on a sunny windowsill or grow seedlings 3-4 inches beneath fluorescent plant lights turned on 16 hours per day, off for 8 hours at night. Raise the lights as the plants grow taller. Incandescent bulbs will not work for this process because they will get too hot. Most plants require a dark period to grow, do not leave lights on for 24 hours. · Seedlings do not need much fertilizer, feed when they are 3-4 weeks old using a starter solution (half strength of a complete indoor houseplant food) according to manufacturer’s directions. · If you are growing salvia in small cells, you may need to transplant the seedlings to 3 or 4 inch pots when seedlings have at least 2 pairs of true leaves before transplanting to the garden so they have enough room to develop strong roots. · Before planting salvia out in the garden, seedling plants need to be “hardened off”. Accustom young plants to outdoor conditions by moving them to a sheltered place outside for a week. Be sure to protect them from wind and hot sun at first. If frost threatens at night, cover or bring containers indoors, then take them out again in the morning. This hardening off process toughens the plant’s cell structure and reduces transplant shock and scalding.