To successfully fertilize and prune your Green Giant arborvitae, here are some detailed guidelines based on the best practices for this planting:

Fertilization

1. Timing: Since it's March 20 in Long Island, NY, you are in the optimal window for fertilizing your Green Giants. Early spring is the best time to apply fertilizer to promote healthy growth.

2. Type of Fertilizer: It is recommended to use a slow-release granular fertilizer, particularly one high in nitrogen. This type of fertilizer will provide a steady supply of nutrients over time, which is beneficial for the growth of arborvitae.

3. Application Method:

   • Apply the fertilizer around the base of the tree, following the manufacturer's instructions regarding the amount. Make sure to evenly distribute it on the soil surface.
   • After applying the fertilizer, water the area thoroughly to help the nutrients penetrate the soil and reach the roots.

Pruning

1. When to Prune: The ideal time to prune Green Giants is in the spring, just before new growth begins. This enhances the plant's natural shape and encourages fresh, healthy growth.

2. Pruning Technique:

   • Use sharp, clean pruning shears to avoid damaging the plant.
   • Focus on removing any dead or damaged branches. Also, you may trim back excessively leggy or overgrown branches to maintain the desired shape and size.
   • Avoid cutting back into old wood that has no green growth, as this may not produce new shoots.

Additional Considerations

• Monitor the trees regularly for signs of stress or disease, especially after fertilizing and pruning.
• Always test the soil if you're unsure about its nutrient content, as arborvitae are not heavy feeders and may not require frequent fertilization.

For additional resources and tips, you may refer to the following links:

• How to Fertilize Green Giant Arborvitae
• Fertilizer For Arborvitae: How And When To Feed Arborvitae Trees
• Thuja Green Giant info

By following these guidelines, you can ensure that your Green Giant arborvitae thrive and remain healthy as they continue to grow.In Long Island, NY, as of March 20, it is an ideal time to fertilize and prune your Green Giant arborvitae. Here’s a detailed summary of how to care for them effectively.

Fertilizing Green Giant Arborvitae

1. Timing: Fertilizing should be done in early spring, ideally March or April, to promote vigorous growth as the growing season begins.

2. Type of Fertilizer: Use a slow-release granular fertilizer, particularly one high in nitrogen, as this will benefit the growth of your arborvitae. A good NPK (Nitrogen-Phosphorus-Potassium) ratio for this purpose would be beneficial.

3. Application Method: Apply the fertilizer around the base of the tree. Spread it evenly across the root zone, which usually extends to the outer edge of the branches.

4. Watering: After applying the fertilizer, be sure to water the area well. This helps the fertilizer penetrate the soil and reach the roots effectively.

For more detailed instructions on fertilization, you can refer to this guide or this resource.

Pruning Green Giant Arborvitae

1. Timing: Early spring is also the best time for pruning just before new growth begins, which helps maintain the shape and health of the tree.

2. Pruning Technique: Focus on the upper fifth of the tree for any top growth that may be excessive. Use removal cuts to eliminate branches entirely and reduction cuts to shorten branches by cutting back to a lateral side branch.

3. Avoid Over-Pruning: Be cautious not to remove more than one-third of the total length of any single branch, as this can harm the tree's health.

4. General Care: Try to leave some foliage in the clipped areas, as bare branches typically won’t regrow leaves.

For practical tips on pruning, check out this article which provides valuable insights.

By following these guidelines, your Green Giant arborvitae should thrive and maintain a healthy, attractive appearance as they grow.

Sources

How To Prune Arborvitae 'Green Giant' – Hickory GroveTrimming/Pruning Green Giant Arborvitae. - YouTubeHow to Prune an Arborvitae That's Too Tall or Wide - Fine GardeningThuja Green Giant Guide - The Tree CenterHome - Arborvitae (Thuja) - Research Guides at New York Botanical ...RE: Pruning Green Giant Arborvitae - Garden WebEffective Advice on How and When to Trim Arborvitae

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