Dahlia Dahlia 'Knockout' (PBR) (Sin)

Water

Dahlias require even moisture to thrive, so it's important to water the 'Knockout' variety regularly, especially during dry periods. Provide a deep watering to soak the soil around the roots, which typically means using about 1-2 gallons per plant, depending on soil and weather conditions. Aim to water early in the morning to allow foliage to dry out during the day, reducing the risk of fungal diseases. During peak summer months, watering may be needed two to three times a week; however, cut back to once a week when the weather is cooler or if rainfall is sufficient.

Light

Dahlias, including the 'Knockout', prefer a sunny location where they can receive at least 6 to 8 hours of direct sunlight each day. An ideal spot is one with morning sunlight and some afternoon shade in areas with particularly hot climates, to protect the flowers from midday heat. Avoid placing them where buildings or other large plants might cast too much shade on them, as this can impact blooming.

Temperature

Dahlia 'Knockout' plants fare best in temperatures that are consistently between 60 and 75 degrees Fahrenheit. They can survive minimal dips in temperature, but frost is a serious threat, so they should not be subjected to environments where the temperature falls below 50 degrees Fahrenheit. Hot temperatures over 90 degrees Fahrenheit can also stress the plant; therefore, some shade during the hottest part of the day can be beneficial to prevent heat stress.

Pruning

Pruning dahlias such as the 'Knockout' variety involves removing dead or spent flowers, a practice known as deadheading, to encourage continued blooming and maintain plant vigor. Additionally, cutting back any broken or diseased stems as soon as they're noticed helps to keep the plant healthy. Prune dahlias during the flowering season, typically from midsummer to early fall, as needed to promote robust, bushy growth and ample blooms.

Cleaning

As needed

Soil

Dahlias prefer well-draining soil rich in organic matter. For Dahlia 'Knockout', a soil mix with two parts garden soil, one part peat moss or coco coir, and one part perlite or sand works well. Ensure the soil pH is between 6.5 and 7.0 for optimal growth and bloom production.

Repotting

Dahlias grown in containers, like the Dahlia 'Knockout', should typically be repotted every year, preferably in the spring just before the new growth starts. When repotting, choose a container only one size larger to prevent stressing the plant.

Humidity & Misting

Dahlia 'Knockout' thrives in moderate humidity conditions. It does not require high humidity levels; ambient outdoor humidity is generally sufficient for this plant. Avoid placing it in overly dry or highly humid environments to maintain healthy growth.

Suitable locations

• Indoor

  Place in bright, indirect light and keep soil moist.

• Outdoor

  Full sun, rich soil, regular water, deadhead spent blooms.

• Hardiness zone

  8-11 USDA

Life cycle

Dahlia 'Knockout' typically begins its life as a tuber or a seed. In the spring, after the last frost, the tubers are planted in well-draining soil, where they will sprout and grow into a small bush with strong stems and foliage. Throughout the summer, the plant starts to develop buds that eventually bloom into large, vividly colored flowers, which can range in color depending on the variety. After flowering, the plant sets seeds, but for cultivation purposes, the tubers are the primary means of propagation. As the weather cools and the first frost of autumn approaches, the dahlia plant dies back, with the stems and leaves withering. The tubers then remain dormant underground throughout the winter until the following spring signals the start of a new growth cycle.

Propogation

• Propogation time

  Spring-Early Summer

• The most popular method for propagating Dahlia 'Knockout' is through division, which is typically carried out in the spring just before new growth begins. To propagate dahlias by division, carefully lift the tuberous roots from the ground after the foliage has been killed by frost in the fall, and store them in a cool, dry place over the winter. In the spring, each clump of tubers should have at least one eye, or growth point. Using a clean, sharp knife, divide the clump so that each division has at least one eye. The cut surfaces can be treated with a fungicide to prevent rot. These divisions can then be planted directly into the garden, positioned so that the top of the tuber is about 4 to 6 inches (10 to 15 centimeters) deep, depending on the size of the tuber.