The best percentage of shade cloth for greenhouse plants isn’t a one-size-fits-all answer.It depends on several factors,including:
Types of plants:Different plants have different light requirements.Sun-loving plants like tomatoes and peppers need more light,while shade-tolerant plants like lettuce and ferns prefer less.
Climate:Hotter climates generally require a higher percentage shade cloth to prevent overheating.Cooler climates might not need any shade cloth,or only a low percentage.
Time of year:The intensity of sunlight changes throughout the year.You might need a higher percentage shade cloth during the summer months and a lower percentage or no shade cloth during the spring and fall.
Greenhouse orientation and covering material:A greenhouse that receives direct sunlight all day will need more shading than one that’s partially shaded by trees or buildings.The greenhouse covering material itself can also influence the amount of light that enters.
Here’s a general guideline:
30-40%shade cloth:This is a good starting point for many greenhouse plants,offering a balance between sun protection and sufficient light.It’s suitable for leafy greens,herbs,and some flowering plants.
40-50%shade cloth:Provides more protection from intense sunlight and is suitable for plants that prefer partial shade or during the hottest parts of summer.Good for ferns,orchids,and some vegetables.
50-60%shade cloth:Offers significant shade and is best for plants that are very sensitive to direct sunlight or in extremely hot climates.
70%or higher shade cloth:Used for providing heavy shade,often for propagating plants or protecting them from extreme heat.
Instead of fixating on a single percentage,consider a more flexible approach:
Layering shade cloth:Start with a lower percentage shade cloth and add layers as needed during periods of intense sunlight.This allows you to adjust the level of shade easily.
Using retractable shade systems:These systems allow you to control the amount of shade based on the weather and the needs of your plants.This is the most adaptable solution.
Monitoring your plants:Pay attention to how your plants are responding to the light levels.Signs of too much sun include wilting,leaf scorch,and stunted growth.Signs of too little sun include leggy growth and pale leaves.
Example Scenarios:
Leafy greens in a hot summer climate:You might start with 40%shade cloth and add another layer of 30%if necessary,effectively creating 58%shade(1-(1-0.4)*(1-0.3)=0.58).
Tomatoes in a mild spring climate:30%shade cloth might be sufficient.
Seedlings:A higher percentage,like 50-70%,can protect delicate seedlings from intense sunlight.
By understanding the factors influencing shade cloth effectiveness and monitoring your plants,you can create the optimal light environment for healthy growth in your greenhouse.
