Lupines, with their striking vertical flower spikes, can bring a beautiful display to any garden space, including patios and balconies. While traditionally grown in garden beds, these vibrant plants can also flourish in containers. Growing lupines in pots offers flexibility, allowing gardeners to enjoy their beauty even with limited space. This approach requires specific considerations for their unique growth habits to ensure successful cultivation.
Is Container Growing Suitable for Lupines?
Growing lupines in pots is possible, though challenging due to their long taproot system. This deep root structure makes them difficult to transplant once established.
However, container growing offers benefits like portability, allowing for optimal sun exposure or protection from harsh weather. It also provides precise control over soil conditions, which is helpful given lupines prefer specific characteristics.
Selecting the Right Pot and Soil
Containers for lupines should be deep enough for taproot development, with a minimum depth of 12 inches recommended for single plants. A 12-inch diameter is also suitable.
Excellent drainage is necessary, so select pots with ample drainage holes. Materials like composite resin, plastic, or terracotta can be used. An all-purpose, lightweight, and free-draining potting soil is ideal to prevent waterlogging. Lupines prefer neutral to slightly acidic soil, with a pH between 5.0 and 6.5.
Planting and Initial Care
The optimal time to plant lupines in pots is during early spring as the plant emerges from dormancy. When planting from nursery starts, loosen the roots gently from the root ball before placing the plant in the prepared pot. Ensure the growth crown is level with the soil surface. For seeds, scarifying the hard outer coat by nicking or sanding, then soaking them for 24-48 hours, can improve germination rates.
Sow seeds about 1/4 inch deep in moist seed compost mixed with perlite for drainage. Keep the soil consistently moist but not waterlogged until germination, which can take up to 10 days. After planting, thoroughly water the container until water drains from the bottom, ensuring the entire soil volume is saturated. New transplants should be kept out of direct sunlight and wind for a few days to help them establish.
Ongoing Care for Potted Lupines
Lupines thrive in full sun, requiring at least six hours of direct sunlight daily for optimal blooming. In hotter climates, some afternoon shade can prevent stress. Consistent moisture is important; water when the top 1-2 inches of soil feel dry, ensuring drainage from the pot bottom. Larger pots may retain moisture longer, but daily monitoring is important.
Lupines are legumes and produce their own nitrogen, so they do not require heavy fertilization. Excessive nitrogen can lead to lush foliage at the expense of blooms and may attract pests. A liquid fertilizer with higher phosphorus and potassium (e.g., 2-6-4 or 0-4-2 NPK) can be applied every two weeks during the growing season to encourage flowering. Deadheading spent flower spikes extends the blooming period by encouraging new blooms instead of seeds.
Winter Care for Potted Lupines
Lupines are hardy perennials and can withstand cold temperatures. For potted lupines, winter care primarily involves protecting their roots, which are more exposed to cold than those in the ground. As autumn progresses, move containers to a sheltered location away from strong winds and storms.
Insulating the pot with layers of burlap or horticultural fleece can help protect the root system from extreme cold. In very cold regions, containers can be moved into an unheated garage or cellar. During dormancy, reduce watering significantly, ensuring the soil does not become waterlogged, which can lead to root rot. The plant needs a period of dormancy to regrow in the spring.
Troubleshooting and Common Issues
Container-grown lupines may face specific challenges. They can become root-bound due to their deep taproot; if roots emerge from drainage holes, repot into a larger container, handling the taproot with care. Lack of blooms can result from insufficient sunlight or over-fertilization with nitrogen, which promotes leaf growth over flowers.
Pests like aphids, slugs, and snails can be an issue. Good air circulation helps prevent powdery mildew. Proper watering and drainage are important to avoid root rot, a common problem if soil remains soggy.