
Black shade cloth is often the preferred fabric color because it blocks more UV rays from reaching the plants underneath. A layer of heat does form immediately beneath the cloth, but if the cloth doesn’t touch plants directly (allowing air to circulate), heat will rise through the fabric (image: epicgardening.com).
By John Green, Texas Certified Expert Gardener, Orange County, TX
Summers’ intensity and heat have quickly ramped up in SETX. The sun’s rays and intense heat, coupled with increasing humidity are impactful environmental challenges people, pets, and plants face daily which can quickly become problematic and have dire consequences if exposure is for a lengthy period. Gardeners need to remain vigilant and aware of heat-related illness (heat stress). Heat cramps, heat exhaustion, and heat stroke symptoms can develop rapidly or gradually, and we need to be able to recognize the signs.
Gardeners need to acclimate themselves gradually to the heat, until unaccustomed to it. When working outdoors, it’s best to wear light-colored, lightweight, loose-fitting clothing, drink plenty of fluids (water & sports drinks are good choices while coffee & alcoholic beverages are not), limit outdoor exposure during the ‘heat’ of the day (not during 10am to 4pm), take frequent breaks in shady, cool areas and monitor yourself and others for signs of heat-related illness. It’s important to note that pets and plants also need a respite from the sun’s burning intensity. Requiring increased amounts of water and shade.
A shade cloth can be simple or complex, purchased, or created from repurposed materials. Anyone can craft a makeshift shade cloth simply by using a bed sheet, row cover, window screen, or wooden lattice, to name a few. There are materials available for purchase, such as loosely woven fabrics which are specifically designed to provide shade. Shade cloths are used to reduce the amount of sunlight and heat that reaches plants protecting them from sunburn and sunscald while reducing temperature. Research indicates shade cloths can improve crop yields, photosynthesis, reduce risk of plant sunburn, and can increase the growing season. Photosynthesis occurs when leaves are between 50 to 70 degrees Fahrenheit with increased sunlight equaling better production…up to a point! Once the temperature increases above 80 degrees, production begins to stall in some vegetables, herb, and fruit, which means shading plants during intense heat can bolster plant yields.
Shade cloth is a valuable tool in gardening by providing partial shade to plants and assisting mitigate the effects of intense sunlight and high temperatures. For effective use, consider placement, structure, and shade cloth density to protect plants. Ensure the cloth is securely attached to a structure elevating it above the plants to allow for adequate air circulation.
Shade cloths are manufactured in various colors, different material types and density levels, each of which can impact the amount of sunlight the cloth physically blocks. More important than the fabric type is the density level of the shade cloth. For instance, a 10% density level provides extremely light cover (blocking a mere 10% of sunlight), conversely an 80% density level cover will block 80% of the sunlight. Vegetables and herbs require a lot of sunlight and will not grow will using a shade cloth with 90% density, as too much sunlight is blocked. Shade loving plants such as cabbage or chives will not survive using a 10% shade cloth. Select a shade cloth between 30% to 60% for best results across several plant species and types.
Considerations
Shade percentage for specific plants (lower percentages vegetables and flowers, higher for shade-loving plants or intense heat). Shade cloth is available in different densities, measured by the percentage of sunlight they block. This can range from 30% to 90% with 30% to 50% being suitable for most vegetables and flowering plants that need some sun protection. The 60% to 90% density is better for shade-loving plants, succulents, or in extremely hot climates to shield humans, pets and sensitive plants.
Color (lighter for warmer climates, black for cooler climates or heat-loving crops)- black shade cloth absorbs light and blocks more UV rays (perfect for our area), while white shade cloth reflects light and keeps the environment cooler.
Material (knitted for better durability and ventilation)- is durable and allows for good ventilation. Woven fabric is heavier and often used in colder climates.
Placement- position the shade cloth to maximize coverage, especially above raised beds and potted plants which are exposed to direct sunlight for more than 8 hours.
Structure- provide support using a structure to prevent it from resting directly on top of plants. Use wood or metal poles, cattle panels, hoops, or even tomato cages. Use materials strong enough to withstand wind and heavy rainfall events, otherwise plants beneath the shade cloth might be damaged if the shade cloth collapses.
Attachment- ensure the shade cloth is tight and secure to prevent it from flapping in the wind or sagging. Securely attach the shade cloth to the structure using clips, clips with grommets, tie wraps, wire, or rope.
Installation- measure the area and prepare a support structure above the plants. Attach the cloth securely covering the area and secure the edges, and check for light penetration and adjust as necessary.
Shade Cloth Tips
- Watering- using shade cloth helps retain soil moisture, regular watering is still important, especially during hot weather.
- Observation- keep a watchful eye on how plants react to the shade cloth and adjust as needed. Some plants might thrive with less shade, while others might need more.
- Experiment- by using different shade cloth densities and colors to determine which works best for the specific garden area.
- Removal- once temperatures begin to fall (in cooler weather) or during periods of less intense sunlight, remove the shade cloth to allow plants access to full sun exposure.
Effective use of shade cloths can help plants thrive even in our challenging weather conditions with an additional benefit of increased harvest!
So long for now fellow gardeners, let’s go out and grow ourselves a greener, more sustainable world, one plant at a time! For answers to your gardening questions, send me an email: jongreene57@gmail.com.
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