How to Grow Flowers From Seed Using a Portable Greenhouse

Fill each cell of the planting tray with organic potting mix. Dampen the potting mix with the spray bottle. Plant seeds in each of the tray cells according to the directions on the flower seed packet.

Determine the best location for your greenhouse. During winter months, an area that receives full sun for most of the day is usually best. South and south-easterly facing locations generally provide the best lighting. During hot summer months, a location that receives moderately filtered light will reduce chances of baking your seedlings. Check the seed packages for specific information regarding the lighting needs of individual plants. Plants that do not have similar lighting needs do better in separate greenhouses.

Regulate moisture inside the greenhouse. While most seeds readily germinate in warm, moist conditions, too much of a good thing results in problems with mold, fungus and mildew, which will kill your seedlings and discourage flowering. While there should be a light film of moisture on the inside walls of the greenhouse, there should not be so much condensation that it pools up on the floor of the greenhouse. Placing the greenhouse on soil that drains freely is best, but lining the floor of the greenhouse with gravel, or placing planting trays on bricks to raise them off the ground also helps. Place the planting trays inside your greenhouse. Place them on shelves, if using a commercially manufactured greenhouse; otherwise, raise the trays off the ground with bricks.

Maintain healthy air circulation inside the greenhouse. Without proper air circulation, seeds will rot instead of sprouting, and flowers will be vulnerable to pests. Most commercial portable greenhouses have ventilation flaps near the top of the roof or vents near the base to allow air to flow through. This helps to reduce temperatures when needed, while also inhibiting the growth of fungus and mold. Seeds will not grow in a completely closed-in environment. Flowering plants that require insects for propagation need vents for access. Flowering plants that have low humidity needs benefit from having permanently opened flaps, while plants that flourish under high humidity require only an hour or two of ventilation a day.

Water your plants thoroughly, but allow them to drain well. For smaller greenhouses, a spray bottle is sufficient to provide enough moisture between waterings. For larger greenhouses, a mister attachment on a garden hose works well. Aim for a humid environment, rather than a swamp.