Planting flower seedlings is an easy activity that requires only a small number of supplies and a little knowledge. Seeds, water, soil, and sunlight are needed to start seedlings. While most plants are started inside and kept there until the last frost is over, it is best for some seeds to be planted directly into the ground outside.
It is important to choose the correct type of soil when starting flower seedlings. Using a seed-starting mix is typically recommended over using regular garden soil. Seed starting mix is light and spongy and holds moisture well. Often it can be found already mixed with compost, which is an excellent source of food and fertilizer for growing plants.
A number of different containers can be used to plant flower seedlings, but some gardeners choose to fill a “flat” with seed starting soil. A flat is a wide and long shallow container, several inches deep. After the flower seedlings have sprouted, the strongest plants can be transplanted into larger containers to give them room to grow. Other gardeners plant their seeds in small containers that may be specially made for seed starting, such as peat pots, or may be something repurposed, such as disposable drinking cups. Whatever the container used, it should be several inches deep and have a hole at the bottom for drainage.
Along with a good growing container and soil, flower seedlings need appropriate light. Once the seeds sprout, they will need direct sunlight, which can be accomplished by placing them on a window that receives six to eight hours of direct sunlight every day. If this is not possible, flower seedlings can also be placed under fluorescent light. They must be placed in very close proximity, 3 to 4 inches (7.62 to 10.16 centimeters) to these lights.
Although most flower seedlings should be started inside, some plants that grow very large or that grow very fast are usually started outside. This information is typically listed on the seed package. Seeds started outside are usually placed or sprinkled, depending on the type of seed, over an area, with seed starting mix placed on top of them. These seeds are generally planted after the last spring frost, but the seed packet will specify prime planting times.
Plants can be transplanted outside after the last spring frost. By this time, seedlings should have grown beyond their first leaves. The first leaves are the two small leaves that appear first on a plant, are typically fragile, and do not resemble the plant’s actual leaves. By this time they should be several inches tall, although the exact height depends on the plant.