Flowers Through the Seasons: What to Plant in Your Greenhouse for Year-Round Beauty

A greenhouse is every gardener's dream, allowing people to grow flowers, herbs, and vegetables regardless of the season. With planning, greenhouses can overflow with color and scent all year long, as the protected environment lets you extend growing seasons and cultivate plants that usually couldn't handle your climate. Learning about which annuals, perennials, and bulbs thrive in a greenhouse during each season and mixing blooms and foliage will allow your greenhouse to remain a beautiful oasis all year.

Spring

The arrival of spring is an exciting time for greenhouse gardeners. After the winter dormancy, it's time to plant a fresh crop of flowers and greenery. Spring's increasingly warm and sunny days make it an ideal season for cool-weather annuals, blooming bulbs, and hardy perennials. Start preparing your greenhouse in early spring by clearing out any dead growth from the winter and turning over the soil. Then, mix in compost or fertilizer to replenish nutrients. Popular annuals for spring planting include snapdragons, stocks, calendulas, and violas. Cheerful pansies are another excellent choice; they can even tolerate light frosts. Flowering bulbs like tulips, daffodils, and hyacinths add color and fragrance. Perennials from seed or young plants might include foxgloves, columbines, and veronicas. When planting, ensure that young seedlings and plants receive ample moisture and sunlight. Ventilate the greenhouse during warm days.

Summer

Summer's heat and humidity can be challenging for greenhouse gardeners, but a greenhouse can thrive during the hot months with careful management. Proper ventilation, shade control, and irrigation are critical. On very hot days, ventilate the greenhouse by opening doors, windows, and vents. This allows excess heat to escape and prevents the plants from getting scorched. You may need to install shade cloth, greenhouse paint, or window treatments to filter intense sunlight. Adding fans improves air circulation as well. Many colorful annuals love summer's warmth and long days. Zinnias, marigolds, petunias, and geraniums are good choices. Tropical plants like mandevilla, hibiscus, and orchids will also flourish. Monitor soil moisture closely and water early daily to avoid foliar diseases. For plants that prefer a humid environment, misting and gravel trays can help increase humidity.

Fall

As summer's heat gives way to crisp autumn air, it's time to transition your greenhouse for the cooler months ahead. One benefit of a greenhouse in fall is extending the growing season so you can continue harvesting fresh flowers and produce after the outdoor garden fades. To prepare for fall, remove any heat-loving annuals that have run their course. Keep vents open to refresh the air on cooler days. This is an excellent time to plant autumn-blooming flowers like chrysanthemums, asters, and flowering kale. Hardy herbs like parsley, sage, and thyme will also thrive now. You can also start seeds of cold-weather crops, including spinach, lettuce, and broccoli. As nighttime temperatures drop, you may need to provide extra insulation and heat, especially if you're attempting to overwinter tender plants. Install thermal greenhouse film and use portable heaters as required. And stay vigilant about pests like aphids that seek might shelter in the greenhouse.

Winter

Winter's short days and frigid temperatures may seem unfriendly, but a greenhouse can still flourish with extra care. You'll likely need a heat source like a space heater or heated propagation mats to keep your greenhouse warm enough for overwintering plants. Insulate the structure with thermal blankets or plastic sheeting to retain warmth. Maximize sun exposure by removing shade cloth and pruning back overgrown plants. You can supplement natural light with grow lights or reflectors. Focus on low-light bloomers like cyclamen, orchids, and camellias. Poinsettias are a holiday favorite. Plant cold-hardy pansies, kale, and Swiss chard for winter color and harvests. Evergreen trees like citrus or olive trees can survive the dormant months in a greenhouse, too. Remember to water plants less frequently in winter, but don't let them dry out completely. Monitor for pests and diseases in the warm, enclosed environment. With good cold protection and bright light, you can keep your greenhouse going even when there's snow on the ground. The efforts will pay off in spring.

Additional Resources

• Growing in the Greenhouse in Winter
• Gardening in a Greenhouse: Small Container Planting Guide
• Here Are the 35 Best Things to Grow in Your Greenhouse
• Basic Plant Care: Understanding Your Plant's Needs
• The Best Colorful Blooms to Grow in a Small Greenhouse
• What Makes Plants Bloom at Different Times of the Year?
• Growing Garden Mums for Fall in a Greenhouse
• Turning Winter Into Summer With a Greenhouse
• Planting a Greenhouse Winter Garden
• 20 Stunning Winter Flowering Plants
• Building a Four-Season Greenhouse

The page was created by Chad Kremp