6 Courtyard Cooling Fixes That Help Plants Beat the Heat and Stay Lush All Summer
Expert solutions to improve airflow, reduce mildew and keep plants healthy
The air in enclosed courtyards and urban walled gardens can feel humid and stagnant in summer. High walls, fences and dense planting can restrict air movement and create the perfect conditions for fungal disease, pest infestations and struggling plants.
Knowing how to increase airflow in a courtyard can make a significant difference to plant health. According to landscape designer Caroline Ervin, there are several visible signs that indicate that plants are not getting enough air circulation. 'The appearance of powdery mildew or mold is a very obvious sign that the air is stagnant. Additionally, the leaves of plants will curl or turn yellow if they are not getting enough air and oxygen around them,' she explains.
The good news is you don't need to completely redesign your garden to improve the airflow in an urban courtyard. A few simple changes to how you plant, water and arrange your space can create a healthier growing environment. These easy, expert-approved solutions will help protect your plants from summer heat issues and can be incorporated into your favorite summer courtyard garden ideas.
1. Prune Plants To Create A More Open Structure
When leaves and stems become tightly packed together, moisture lingers for longer after rain or watering, which creates ideal conditions for fungal diseases, such as powdery mildew, to take hold.
'Proper pruning and thinning of plants can reduce the risk of moisture buildup and increase airflow around the plants,' says Caroline Ervin. 'This does not mean shearing the plants to a smaller size or shape, but rather hand pruning to allow for air circulation into the interior portions of the plants.'
Landscape designer Brooke Addison recommends taking a similar approach. 'Strategic pruning will help open plant structure and keep air from becoming trapped,' she says. 'Open space encourages better airflow. I would also clear lower branches and leaves to provide separation from the soil. This will help with airflow and decrease soil-spread diseases.'
The same thinking applies when introducing new plants to a courtyard. Plants that appear neatly spaced when first planted can quickly grow together and restrict airflow as they mature.
'Be sure to space plants based upon their mature size, not the size that they are when planted,' adds Caroline. 'If a shrub is 4 feet wide at maturity, there should be at least 4 feet of space between the center of that plant and the center of the plant next to it.'
Allowing enough room for plants to reach their full spread will help maintain healthy airflow and reduce the need for corrective pruning at a later stage.
Where to buy: These Felco Secateurs from Amazon have an ergonomic hand fitting design and are suitable for every type of pruning.
Caroline is a landscape designer. She has worked with clients since 2007 to install and maintain small and large residential gardens in Washington DC. She has more than 20 years hands-on experience gardening.
2. Rethink Where You Place Furniture And Containers
It's easy to focus solely on plants when you're trying to increase airflow in a courtyard, but simple design tweaks, such as where you place furniture and containers, can have an impact too.
'Do not crowd furniture, especially dense furniture with cushions, next to plants that prevents or impedes airflow around the plants,' says Caroline. In small courtyards, bulky seating, outdoor sofas and large patio umbrellas can unintentionally block natural air from moving and trap humidity around nearby foliage.
If your courtyard has windows or decorative openings in the walls, Brooke recommends keeping those areas clear. 'Keep these areas clear of potted trees or umbrellas to maximize airflow into the garden,' she says. These areas act as natural ventilation points, helping fresh air move through the space.
When arranging a courtyard, think about how air will move through the space in the same way you'd think about sunlight. Leaving clear routes between furniture, containers and planting can make a noticeable difference to plant health during the summer months.
Where to buy: Shop outdoor planters, such as this Bloem Terracotta design from Target, which is available in various sizes.
Sustainable landscape designer and small business owner based in Seattle, WA, working with homeowners across the U.S. Specialising in ecological, water-wise gardens that support both people and wildlife, Brooke is a Certified California Native Plant Landscaper and Certified Water Harvesting Practitioner, with additional training in permaculture, sustainable landscaping, and ecological design aesthetics. She is also a member of the Association of Professional Landscape Designers.
3. Water Plants Earlier In The Day
One simple but effective way to look after your plants in a stagnant courtyard is to make sure you are watering plants at the best time of day.
As Brooke explains, watering technique can unintentionally make fungal disease situations worse. 'The best method is to water plants early in the morning. This allows your plant to absorb the moisture it needs before the sun evaporates the water and dries the soil.'
Brooke also points out that mid-day watering increases the chance of the sun burning wet leaves and decreases water efficiency. Watering in the evening isn't always harmful, but repeatedly leaving leaves damp overnight can create conditions that diseases and pests thrive in. This is particularly important if you're growing plants that need more water in a heatwave, where high temperatures can put them under more pressure.
How you water plants matters too. 'Overhead watering where we splash soil up onto the leaves spreads fungal spores,' adds Brooke. Directing water at the base of plants rather than spraying foliage can also help reduce moisture build-up.
Where to buy: A long-spouting watering can make it easier to direct water at the base of the roots. This 1 gallon metal watering can is available from Amazon, and comes in a variety of colours.
4. Keep Shrubs Away From Walls
Where you position shrubs can have a noticeable impact on airflow in a courtyard garden. While it might be tempting to use them to soften walls and boundaries, planting them too close to buildings can create areas of stagnant, humid air where fungal diseases can then spread.
'Avoid placing shrubs directly against an exterior wall,' advises Brooke. 'It can be difficult to prune if your house is blocking access to half the plant. The lack of light to the whole shrub will also cause dieback in those areas that aren’t getting sunlight - and the lack of airflow means an increased risk for plant diseases.'
For those with a planting area outside the courtyard wall, Brooke suggests layering plants at increasing heights outside the boundary; a technique she calls a wind ladder. 'If we can plant in a succession of plant heights, groundcover, perennial, shrub, tree, this disrupts the flow of the wind and produces more turbulent wind patterns that encourage mixing swirls over the edge of the courtyard wall,' she explains. Rather than being deflected around the sides, air tumbles down into the garden instead.
Giving shrubs enough space also makes routine maintenance easier, allowing you to prune and thin growth as needed to keep air moving through the plant.
Where to buy: For heavier pruning of established shrubs, a good pair of loppers gives you the reach and leverage secateurs can't. These Fiskars Bypass Loppers from Target are lightweight, sharp and suited to thinning out dense courtyard shrubs.
5. Improve Drainage And Switch To Drip Irrigation
Excess moisture is one of the biggest contributors to humidity build-up in enclosed courtyard gardens, so it's important to ensure water can drain away freely.
'Make sure that any plants in containers have plenty of room for the roots to grow and allow for extra water to escape through proper drainage holes,' says Caroline. 'Preventing waterlogged soil is important as it can inhibit plant growth and promote fungal diseases.'
If you regularly find puddles forming after heavy rain, consider whether compacted soil, blocked drainage channels or overcrowded containers could be slowing water movement through the space.
Drip irrigation systems are worth considering for courtyard gardens with multiple containers. 'Drip irrigation or soaker hoses prevent the splashing of spores onto our plants.' says Brooke. By delivering water to the root zone rather than over foliage, they reduce the amount of moisture released into the surrounding air, making it easier to water consistently.
Where to buy: You can buy this Raindrip Drip Watering System from Amazon. It includes a timer and is specifically designed for hanging baskets and containers.
6. Remove Diseased Debris And Add Mulch
Good airflow can prevent fungal problems from developing, but if disease is already present, it's important to remove the source as quickly as possible.
'If you're dealing with plant diseases, you need to remove any fallen leaves or pruned materials from your property, or you'll be dealing with the issue year after year,' says Brooke.
Once the area is clear, a layer of mulch can prevent any remaining spores in the soil from splashing back onto the foliage during watering or rainfall.
Brooke suggests applying mulch around three inches deep around the base of plants, while keeping it pulled back from stems and trunks to avoid trapping moisture against the bark. 'Wet mulch holding moisture against your plant bark will just continue the fungi-loved growing conditions we're trying to avoid,' she says.
Bark mulch is a practical option for courtyard gardens, helping to suppress weeds, regulate soil moisture and reduce soil splash. Just make sure you leave a small gap around the base of the plant.
Where to buy: This Natural Pine Bark Mulch from Amazon can be used as a soil additive for drainage or as mulch to lock in soil moisture.
What To Shop
A self-watering planter helps to keep plants regularly hydrated and healthy. This set of two hand-finished planters from Wayfair are a highly-rated option.
A soil moisture meter takes the guesswork out of watering, helping to avoid overly damp conditions in your courtyard that can cause poor airflow around plants.
Brooke Addison recommends using a circulation fan for particularly enclosed courtyards, helping to improve air movement and create a more comfortable environment for plants.
Paying a little extra attention to the airflow in your courtyard can go a long way to keeping plants healthy and the space looking its best, particularly through the hottest months of the year.
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