What is Foliar Spray?

Foliar spray is a method of delivering nutrients directly to a plant’s leaves instead of the soil. This technique involves spraying a water-dissolved formula onto the leaves, allowing the nutrients to be absorbed through the stomata and the leaf cuticle. This is similar to how humans take an aspirin under the tongue for quicker absorption.

Foliar feeding is effective for rapid nutrient delivery, especially in cases of nutrient deficiencies, and can show visible results within 48 hours.

Benefits of Foliar Spray

Fast Nutrient Uptake: Plants respond almost immediately to foliar feeding. Nutrient uptake is nearly 10 times faster when applied to the leaves compared to the soil. This makes foliar spray an excellent solution for quickly addressing deficiency symptoms.

Customized Feeding: Plants require different nutrients at various growth stages. Foliar applications can be tailored to meet these specific needs, improving crop yield and quality.

Drought Resistance: When the topsoil lacks sufficient moisture to absorb nutrients, foliar spraying can still deliver essential nutrients directly to the plant.

Disease Suppression: Some foliar sprays, like those containing chitosan, can boost a plant’s immune system. This tricks the plant into thinking it’s under attack, enhancing its natural defense mechanisms.

Nutrient Deficiencies: Foliar spray is an effective way to quickly correct nutrient imbalances, especially when the soil conditions are not ideal for nutrient uptake.

Limitations of Foliar Spray

Supplemental Nutrients: The amount of nutrients that can be delivered through foliar spray is often not enough to meet all the nutritional needs of the plant. It should be used as a supplement rather than a primary source of nutrients.

Phytotoxicity: High concentrations of nutrients in the spray can cause leaf burn as the water evaporates and salts remain. To avoid this issue, it’s best to work with a professional landscaping service.

Not a Soil Substitute: While foliar feeding is beneficial, it is not a replacement for healthy soil. The majority of nutrients are still best absorbed through the roots, so maintaining good soil health is crucial.

How to Use Foliar Spray Effectively

Foliar spray can be a game-changer for your trees and shrubs, but using it correctly is key to getting the best results. Let’s dive into the essentials of application timing and more.

Best Time to Apply Foliar Spray

Timing is everything when it comes to foliar spray. The best times to apply are:

• Early Morning: When the air is cool and the plant’s stomata (tiny openings on leaves) are open, making it easier for the plant to absorb nutrients.
• Late Afternoon: This is another good time because the sun is less intense, reducing the risk of leaf burn.

Temperature Considerations: Avoid spraying when the temperature exceeds 75°F. High temperatures can cause the spray to evaporate quickly, reducing its effectiveness and potentially harming the plant.

DIY Foliar Spray Recipes

Creating your own foliar sprays can be a fun way to supplement your plant care routine. While these DIY recipes should not replace professional plant care, they can be a great addition for hands-on gardeners. Here are some simple recipes you can try:

1. Compost Tea
   • Ingredients: 1 part well-aged compost, 5 parts water
   • Instructions: Mix the compost and water in a bucket. Let it steep for 24-48 hours, stirring occasionally. Strain the mixture through a cloth to remove solids. Dilute the tea with water (1:10 ratio) before using it as a foliar spray.
2. Seaweed Solution
   • Ingredients: 1 tablespoon seaweed extract, 1 gallon water
   • Instructions: Mix the seaweed extract with water in a spray bottle. Shake well before use to ensure even distribution.
3. Rainwater Mix
   • Ingredients: Rainwater, a few drops of liquid soap (optional)
   • Instructions: Collect rainwater in a clean container. Add a few drops of liquid soap to help the spray adhere to the leaves. Pour the mixture into a spray bottle and apply directly to your plants.

Remember, always test a small area of the plant first to ensure it responds well to the spray.

Dos and Don’ts of Foliar Feeding

To make the most out of your foliar spray, here are some critical dos and don’ts:

The Dos:

• Do Apply in the Dark: When a plant enters a dark period, its stem and leaves take about 15 minutes to relax. This is an optimal time for foliar spray.
• Do Dilute Properly: Always read the instructions when using a commercial product and stick to the recommended dilution rates. Over-diluting is safer than under-diluting.
• Do Use Proper Spraying Technique: Cover the leaves and stems with a light, misty shower. Ensure you spray the underside of the leaves as well, where stomata are more numerous.

The Don’ts:

• Don’t Spray in High Temperatures: As mentioned earlier, high temperatures can cause leaf burn and rapid evaporation.
• Don’t Spray During Flowering Stage: Foliar feeding increases humidity, which can be detrimental during flowering.
• Don’t Forget to Dilute: Undiluted sprays can cause phytotoxicity, leading to leaf burn.

For the Best Foliar Spray, Partner With the Professionals

Foliar spray offers numerous benefits, including rapid nutrient uptake, customized feeding, and improved drought resistance. By delivering nutrients directly to the leaves, foliar feeding can quickly correct deficiencies and boost plant health. It’s a powerful tool, especially when soil conditions aren’t optimal.

Practical Tips:

• Timing is Key: Apply foliar sprays in the early morning or late afternoon to avoid high temperatures.
• Proper Dilution: Always dilute your foliar spray to prevent leaf burn.
• Check Conditions: Ideal conditions include overcast days and low wind to ensure maximum absorption.

While foliar spray is beneficial, it’s not a substitute for good soil health. It’s a complementary method to ensure your plants receive all the nutrients they need.

At Borst Landscape & Design, we offer expert tree and shrub care services, including foliar spray applications tailored to your garden’s specific needs. Our team of professionals is here to help you achieve a lush, healthy landscape.

Ready to enhance your garden with foliar spray? Contact us at 201-822-9327 or visit our tree and shrub care services page to learn more.

By understanding the benefits and limitations of foliar spray, you can make informed decisions for your garden. Whether you’re dealing with nutrient deficiencies or looking to boost overall plant health, foliar feeding can be a valuable addition to your gardening toolkit. Let Borst Landscape & Design help you make the most of this powerful technique.

Photo by Madison Inouye