Species Diffuse Knapweed
white flowers with yellow-brown buds on green-brown stems

Diffuse Knapweed

Centaurea diffusa

Also Known As - White Knapweed
Diffuse Knapweed is a plant species native to parts of Europe and Asia. It has a short, shrubby appearance, growing up to a meter in height and forming prickly, pointy foliage. Its bright pink flowers bloom from mid-spring to late summer. The plant spreads easily through its prolific seed production as well as through its extensive root system, making it an unwelcome invader in many habitats. Its hardy nature and drought resistance make it difficult to eradicate. If left unchecked, its crowding habit could threaten native species and reduce biodiversity.

Watering:

Average

Hardiness Zone:

Flowers:

Purple|White/Cream Flowers

Sun:

Sun

Soil:

Clay, Sand

Leaf:

Yes

Leaf Color:

green,gray,gray

Growth Rate:

Low

Drought Tolerant:

Yes

Salt Tolerant:

Yes

Invasive:

Yes

Care Level:

Medium

watering

For watering a Diffuse Knapweed, it is recommended to water the plant twice per week during warm weather and every 2 weeks during cooler weather. When watering, it is important to thoroughly saturate the soil around the base of the plant with water. Be careful to not overwater, as this can cause root rot. Be sure to check the soil before watering to ensure it is dry, and stop watering if there is any standing water in the pot.

sunlight

Diffuse knapweed (Centaurea diffusa) plants require full sun for optimal growth and flowering. The plants should receive at least 6 to 8 hours of direct sunlight each day, ideally between midmorning and late afternoon during the summer months. During the fall and spring months, they should receive 4 to 6 hours of direct sunlight. During the winter, the plant should still receive some direct sunlight, and some southern areas of the United States may receive as much as 8 to 10 hours of direct sunlight a day.

pruning

Diffuse Knapweed should be pruned twice a year, in early spring and late summer. During the early spring, Diffuse Knapweed should be cut back to about 1 third of its original height when new growth begins. This will remove any winter damage and encourage long and healthy new growth. In late summer, Diffuse Knapweed should be pruned back even further, cutting the stems nearly to the ground. This will encourage new growth and reduce the risk of winter damage. To maintain a neat and tidy appearance, additional pruning or deadheading can be done periodically throughout the season. By removing dead, damaged, or wayward branches, you can keep Diffuse Knapweed looking tidy and healthy.

Season

Fall
Winter
Spring
Summer
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Starts Flowering

Diffuse Knapweed typically starts flowering in June.