Rosemary seed needs to be started indoors before it is moved outside to ensure the best growth. Small plant starting discs and an indoor container, often sold as a set, can be used to initially plant rosemary seed. Once the plant has a sturdy root system, you can move it to a larger pot or outside in a garden.
Purchasing quality rosemary seed is essential to growing a healthy plant. In most instances, rosemary grows best when propagated from an established plant because lesser quality seeds may not grow well. You will also need to purchase a seed starting kit with a container, lid, and starting discs.
Most starting discs are flat and dry when purchased. To revive them, slowly pour lukewarm water directly over each disc until it doubles in size. Most of the time the kit will tell you approximately how much water is needed. Once the disc absorbs all of the water, typically after five minutes, gently remove the netting from the top of the disc to expose the soil.
Gently fluff the soil with a toothpick or small fork to loosen it. Then, create a small indentation in the center of the disc and place a rosemary seed or two in the hole; gently cover it with soil from the disc. Each disc will produce one rosemary plant. As a rosemary seed will not always grow properly, or at all, it is typically a good idea to plant seeds in a few more starter discs than you actually need. This will allow you to choose the healthiest, sturdiest plants.
Once all of the discs are ready, put the cover over the container and place the kit in a warm room that receives indirect sunlight. Avoid putting the seedlings in direct sunlight because this can cause the rosemary seed to morph or not grow at all. Make sure the discs stay lightly damp, but do not soak them. Once at least one disc has a sprout, set the cover at an angle to allow some air movement while still keeping the seedlings covered. Depending on the variety of rosemary seed planted, this can take anywhere from one to three weeks.
After each rosemary seed has sprouted, remove the cover entirely and allow the plant to grow in the container. As before, keep the soil damp but not soaked. Once there are visible roots on the outside of the disc, usually after three to five weeks, move the plant to another container or a garden. When planting the seedlings, remove the netting from underneath the disc and very gently split the bottom to lose the roots. Place the rosemary plant in high quality soil in a larger container or garden that receives full to partial sun and tend to the plant as needed.
