Morning glories (Ipomoea species) are vigorous annual vines known for their rapid growth and trumpet-shaped blooms that open each morning. These fast-growing climbers quickly cover fences, trellises, or walls throughout the summer season. Companion planting involves placing different plants near each other to maximize garden health and productivity. When working with this determined climber, companion planting is useful for managing its aggressive, twining habit and ensuring a harmonious garden space. Selecting the correct neighbors helps prevent the vine from smothering less robust plants while still allowing the gardener to enjoy its abundant foliage and flowers.
Understanding Morning Glory Growth Requirements
Morning glories require a location that receives full sun for at least six to eight hours each day, as their flowers open in response to direct sunlight. Planting them in a spot with less sun will result in diminished blooming and a shorter period of open flowers each day. These vines are not demanding regarding soil fertility and perform best in average or poor soil that is well-draining. Too much rich, organic matter or nitrogen-heavy fertilizer encourages the plant to produce lush foliage at the expense of its characteristic trumpet-shaped blossoms.
Regular watering is important during the initial growing phase, though established vines show a degree of drought tolerance. Providing about one inch of water per week is sufficient to maintain healthy growth and flower production. The defining trait of the morning glory is its aggressive, twining growth habit, with some varieties capable of reaching lengths of 10 to 15 feet in a single season. This rapid vertical growth is achieved by the vines wrapping tightly around any nearby support, which must be considered when selecting its neighbors.
Beneficial Companion Plants
Certain companions are chosen specifically to provide structural support for the climbing vines, creating a living trellis. Tall, sturdy plants like corn stalks or sunflowers (Helianthus annuus) offer a robust, vertical framework that morning glory vines can easily ascend without damaging the host plant. This arrangement is effective because the large, mature stalks can withstand the strong grip of the morning glory’s twining stems.
Other beneficial pairings focus on improving soil health or managing pests without competing for vertical space. Low-growing herbs like basil (Ocimum basilicum) attract beneficial insects. Plants such as marigolds (Tagetes spp.) help repel nematodes and other harmful garden pests. Nasturtiums (Tropaeolum majus) are another excellent choice, acting as a trap crop for aphids, diverting these common pests away from the morning glory foliage.
Ground-covering plants like marigolds also serve a dual purpose by shading the soil, which helps to retain moisture and suppress weeds around the base of the vine. Nitrogen-fixing plants, such as beans (Phaseolus spp.), can enrich the soil. However, they should be used cautiously, as morning glories prefer lower nitrogen levels for optimal flowering. Beans should be planted with distance to prevent excessive soil enrichment around the vine’s roots.
Plants to Avoid
Heavy feeders, particularly most common vegetables, are a major category of plants to avoid. Plants like tomatoes (Solanum lycopersicum), peppers, and roses require high nutrient levels and will compete aggressively with the morning glory for resources, leading to poor performance for both. The morning glory’s aggressive, sprawling root system can quickly out-compete and stunt the growth of nearby vegetable plants.
Delicate, low-growing annuals should also be avoided, as the dense foliage and rapidly spreading vines of the morning glory will quickly smother them. The vine’s nature is to cover and climb, meaning any small plant below its canopy will be deprived of the necessary light for photosynthesis. Furthermore, planting morning glories near other vining vegetables like pole beans or cucumbers is problematic because the morning glory will dominate the climbing space. This results in a tangled mess that makes harvesting nearly impossible and can strangle the less aggressive vegetable vines.
Plants that share common vulnerabilities to pests or diseases should be kept separate to prevent widespread infestation. Sweet potatoes (Ipomoea batatas) are in the same plant family as morning glories, making them susceptible to the same pests, such as spider mites and fungal issues. Similarly, members of the cabbage family (Brassica spp.) can attract aphids and cabbage moths, which may also target the morning glory vines if planted too closely.
Strategic Placement and Support
Successful companion planting with morning glories depends on strategic placement and providing adequate support. Even when using companion plants like corn as a living trellis, it is beneficial to provide a dedicated, sturdy trellis or fence for the majority of the vine. This separates the bulk of the aggressive growth from less robust neighboring plants.
Proper spacing is important to prevent the smothering of adjacent plants. Maintaining a distance of at least 12 to 18 inches between the base of the morning glory and its companions helps mitigate competition for light and nutrients. Timing the planting is also a factor, as establishing a structural companion, such as a sunflower, before the morning glory seeds germinate gives the companion a necessary head start. This allows the companion to develop a strong stalk capable of supporting the vine’s rapid growth later in the season.