7 Summer Rose Care Tips to Prevent Black Spots

During the hot summer months, roses are often one of the most troublesome flowers to care for—issues such as black spot disease, leaf drop, yellowing leaves, and blackened stems can arise one after another. If it weren’t for the stunning sight of roses in full bloom during spring, many gardeners might be tempted to give up on them altogether! I’m sure many flower enthusiasts can relate. So, how can we avoid these issues and keep roses in relatively good health during summer? At the very least, we can minimize the damage.

The Four Key Aspects of Summer Rose Care

Summer rose care primarily involves four key areas:

• Pest and disease control (requiring continuous attention from spring onwards);
• Proper watering (ensuring adequate moisture while avoiding waterlogging);
• Appropriate shading (especially for potted roses);
• Fertilization management (to prevent root damage caused by high temperatures).

Below, we will delve into each of these aspects in detail.

1. Pest and Disease Control: The “Medicine Cabinet” Nature of Roses

Due to their susceptibility to pests and diseases, roses are often referred to as the “medicine cabinet.” Therefore, regular application of pesticides from spring until the dormant period in winter is essential. We have written numerous articles on rose pest and disease control (refer to past articles or consult the book *Rose Care: From Beginner to Expert*), providing comprehensive control strategies tailored to different seasons. Today, we will focus on the following three aspects.

2. Summer Watering Management: Timing and Techniques

Watering roses in summer is an art that requires special attention to both timing and quantity:

Best watering time: early morning or evening, avoiding watering during the midday heat.

Watering strategies for different plant conditions:

Healthy roses: Water consumption is high, so the potting soil should be kept moist.

Weak seedlings or roses that have already shed their leaves: Transpiration is reduced, so watering should be reduced, allowing the potting soil to dry slightly to promote root growth.

3. Shade and Light Management: Differences Between Potted and Ground-Plant Roses

Roses are typical sun-loving plants, and theoretically, they do not require shade in summer. However, many gardeners have found that roses with appropriate shade grow better. Why is that?

• Ground-planted roses: No shading is needed; ample sunlight promotes robust growth.
• Potted roses: Pots exposed to intense sunlight can become extremely hot, potentially scorching the root system and causing issues like yellowing leaves, leaf drop, and wilting of new shoots.

Shading solutions for potted roses:

• Pot-in-pot method (suitable for a small number of pots);
• Wrap the pot (e.g., using sunscreen foam, cardboard, etc.);
• Adjust placement (choose a location with morning partial shade).

The goal is to lower the soil temperature and create a comfortable growing environment for the roots.

4. Fertilization management: Avoid nutrient imbalance caused by high temperatures

If effective shading is not provided during summer, rose roots may be damaged by high temperatures, leading to absorption issues and nutrient deficiency-related yellowing (e.g., iron deficiency). At this point, fertilization strategies should be adjusted:

Correcting iron deficiency-induced yellowing:

• Avoid using ferrous sulfate for root drenching (which may cause black stems);
• Switch to chelated iron foliar spraying to quickly supplement iron.

Promoting new root growth:

• Combine with rooting agents to help damaged root systems recover and enhance plant vitality.

As long as roses can maintain a healthy state during summer, they will bloom beautifully in autumn after surviving the heatwave!