Description
Knockout lobelia dazzles with towering spikes of deep-red blooms complemented by bronze foliage. ‘Starship Deep Rose’, is a must-grow flowering perennial that blooms the first year. Robust, well-branching plants bring stunning color and contrapuntal verticality to the border, supply an oasis of color in the landscape, and mingle merrily with annuals and perennials in a sunbathing patio container near you. A favorite with the pollinator set.
How to Grow
Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their germination.
Mulches also help retain soil moisture and maintain even soil temperatures. For perennials, an organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
Careful watering is essential in getting perennials off to a good start. Water thoroughly at least once a week to help new roots grow down deeply. Soil should be damp at about 1 inch below the soil surface. You can check this by sticking your finger in the soil. Water early in the morning to give all leaves enough time to dry. One inch of rain or watering per week is recommended for most perennial plants. You can check to see if you need to add water by using a rain gauge.
Until plants become established, some protection from extreme winds and direct, hot sunlight may be necessary. Good air movement is also important.
After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer as higher rates may encourage root rots.
Deadhead to encourage repeat blooming.
Pinch plants if you prefer bushier growth.
Do not cut back in fall, cut back in spring.
Divide every 2-3 years.
Tips
Perennial lobelias are useful for difficult wet locations. They are attractive in the middle or back of the border, and naturalize well in woodlands and along stream banks. They are very effective massed in the landscape.
Lobelias make great cutting flowers as well. Cut when flowers are 1/3 open.
