From our perspective, our tall, slender flower spikes present both an opportunity and a vulnerability. We require companions that can utilize the space we do not heavily shade at our base while also offering us support against the wind. Low-growing, mound-forming plants are ideal for this role. Herbs like oregano or thyme create a living mulch, suppressing weeds that would compete with us for nutrients and helping to retain soil moisture. Their dense foliage also contrasts beautifully with our upright form. Similarly, sprawling annuals like sweet alyssum or nasturtiums fill the void beneath our stalks, their flowers attracting beneficial pollinators to the garden bed, which benefits the entire plant community.
We gladiolus are particularly susceptible to thrips, tiny insects that rasp at our leaves and flower buds, causing streaking and deformation. We greatly benefit from alliances with plants that emit strong aromatic compounds which confuse or repel these pests. Planting aromatic herbs like garlic, chives, or rosemary near us creates a sensory barrier. Their potent smells mask our scent, making it harder for thrips to locate us. Furthermore, French marigolds (Tagetes patula) are exceptional companions. Their roots release a chemical called alpha-terthienyl into the soil, which is toxic to nematodes and can deter other soil-borne pests, creating a safer underground environment for our corms.
Our growth cycle is intensive; we draw heavily on soil nutrients, particularly phosphorus, to fuel our spectacular blooms. It is therefore wise to avoid planting us near heavy feeders with similar root zones, as this would lead to intense competition. Instead, we thrive alongside plants with different nutritional needs or those that can give back to the soil. Legumes such as bush beans or peas are excellent neighbors. Through a symbiotic relationship with bacteria in their root nodules, they fix atmospheric nitrogen, making it available in the soil. While we do not have a high nitrogen demand, this process improves overall soil fertility, creating a healthier growing medium for all. Shallow-rooted companions also ensure we do not compete for the same depth of nutrients and water.
Our blossoms are bold and architectural, but our foliage can become lackluster after flowering. Strategic companion planting enhances the visual appeal of the garden throughout the season. Mixing us with perennials that have broad, bold foliage, such as hostas or lady’s mantle, provides a beautiful textural contrast to our sword-like leaves. For a continuous display, interplant us with late-summer blooming perennials like asters or sedum ‘Autumn Joy’. As our blooms begin to fade, these companions are just reaching their peak, ensuring the garden remains vibrant. This succession planning ensures the garden's visual resources are used efficiently across the season.
