To grow plants in an Aerogarden, select the correct plants, know when to transplant, trim back the seedlings and plant all of the seedlings at the same time. Plastic domes are generally not necessary for an Aerogarden, because it is designed to support adequate germination.
Not all plants are ideal for an Aerogarden. Avoid growing plants that become too big unless you have plans to transfer them later. Plants such as tomatoes and peppers should ideally be transplanted into an outdoor garden once they outgrow the indoor space. Plants that perform well indoors include cilantro, endive, basil and thyme.
Plant one or two seeds of the same plant to avoid overcrowding and nutrient deficiencies. For multiple plants, trim the seedlings a few inches to keep them healthy, and remove the less healthy plants to give the healthy ones a chance to thrive. Leave a few empty pods when planting peppers and tomatoes to allow for healthy root growth.
It is also a good idea to plant the seedlings at the same time so that they grow to roughly the same height. This allows the grow lights to distribute light evenly.
Lastly, prune the plants occasionally, especially when growing them indoors for a long time. This allows the plants to grow faster and live longer.