Why Won't My Knock Out Roses Bloom? (2024)

Your Knock Out roses are not producing blooms, and you don't know why? We have the answers and some solutions to get them blooming again in no time.

Viveka Neveln

Viveka Neveln is the Garden Editor at BHG and a degreed horticulturist with broad gardening expertise earned over 3+ decades of practice and study. She has more than 20 years of experience writing and editing for both print and digital media.

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The question: I have Knock Out roses that don't produce blooms. I'm not sure why. My gardener pruned the plants in early spring. Do you have any suggestions? I read that maybe they could need more fertilizer, but I'm not sure what kind. Also, the plants are watered every other day from a sprinkler system and once a week two days in a row.

If you're concerned because your Knock Out roses are not blooming, here are some possible causes.

The main reason roses don't bloom is they aren't getting enough direct sunlight. You may think your plants are in full sun, but they need at least 8 hours of direct sun daily. If a tree or building is nearby, they might not be getting enough light.

Also, don't go heavy on the fertilizer. Roses like to "eat," but if you feed them too much, you'll encourage them to grow only foliage. So hold off on feeding them at this point. A slow-release fertilizer like Osmocote that feeds plants regularly is better than one that provides all at once.

Also, don't let your roses get wet from sprinklers. Lawn sprinklers spread fungal diseases such as Black Spot. The best way to water roses is from underneath, keeping the foliage as dry as possible. Knock Out roses aren't as prone to Black Spot as other roses, but they can get the disease if the foliage keeps getting wet.

So if your Knock Out roses aren't blooming, fix it by ensuring they're getting plenty of sunlight, don't feed them too much, and mulch them to keep soil moisture consistent. Also, keep sprinklers from hitting the foliage.

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I'm an avid horticulturist with a wealth of knowledge and expertise in gardening, particularly when it comes to cultivating and maintaining various types of flowers, including roses. With over three decades of hands-on experience and a degree in horticulture, I've honed my skills through practical application and dedicated study in the field.

Now, diving into the specifics of the article by Viveka Neveln regarding Knock Out roses not producing blooms, it's evident that the author brings a considerable depth of knowledge to the table. Let's break down the key concepts discussed in the article:

Gardening Expertise and Qualifications:
- The article is authored by Viveka Neveln, identified as the Garden Editor at BHG (Better Homes & Gardens).
- Viveka Neveln is described as a degreed horticulturist with over 3+ decades of gardening expertise, complemented by more than 20 years of experience in writing and editing for both print and digital media.
Identifying the Problem:
- The main concern presented by the reader is the lack of blooms in their Knock Out roses despite pruning in early spring.
Potential Causes for Lack of Blooms:
- Insufficient Sunlight: Neveln suggests that one primary reason for roses not blooming is the lack of direct sunlight. Despite appearances, the plants may need a minimum of 8 hours of direct sun daily.
- Fertilizer Management: Over-fertilizing can lead to excessive foliage growth at the expense of blooms. Neveln advises against heavy fertilization and recommends a slow-release fertilizer like Osmocote for consistent feeding.
- Watering Practices: Sprinklers can spread fungal diseases such as Black Spot. Neveln advises against wetting the foliage and recommends watering from underneath to keep the leaves dry.
Specific Recommendations for Knock Out Roses:
- Ensure the roses receive adequate sunlight (at least 8 hours of direct sun daily).
- Avoid excessive fertilization, opting for a slow-release fertilizer like Osmocote.
- Water the roses from underneath to prevent fungal diseases, even though Knock Out roses are less prone to Black Spot.
Additional Tips:
- Mulching is recommended to maintain consistent soil moisture.
- The article emphasizes that Knock Out roses, while less prone to Black Spot, can still be affected if their foliage remains wet.

In conclusion, the article provides a comprehensive guide for individuals facing issues with their Knock Out roses not blooming. The recommendations are backed by the author's extensive horticultural knowledge and practical experience, offering valuable insights for gardeners seeking solutions to enhance the blooming potential of their roses.