Sky Pencil Holly: The Perfect Plant for Narrow Spaces

Shrubs are small, woody plants that can add beauty to indoor and outdoor spaces. However, many shrubs grow too wide or need frequent trimming, which makes them hard to maintain. They often require specific soil types, regular care, and constant pruning, which can be challenging for gardeners. For those looking for low-maintenance shrubs suitable for narrow spaces, Sky Pencil Holly is a good choice.

Sky Pencil Holly is known for its tall, narrow, column-like shape, making it a unique feature in any garden. It produces small green flowers, and female plants may grow tiny blackberries, although these are not very noticeable. This shrub thrives in containers, making it ideal for framing doors or entryways. It also works well in small garden spaces where wider plants would not fit.

Sky Pencil Holly naturally looks tidy and requires little pruning, making it a great option for formal gardens. Growcycle helps gardeners to plant shrubs and houseplants properly to ensure healthy growth.

Botany of Sky Pencil Holly 

Sky Pencil Holly is a popular evergreen shrub, also known as Ilex crenata 'Sky Pencil,' Japanese holly, Boxleaf holly, and Box-leaved holly. It is from the Aquifoliaceae family and is mainly found in Eastern Asia, Korea, China, and Japan. Because of its upright shape and low maintenance, it is widely used in landscaping.

• Size: It has a narrow shape, usually 6 to 10 feet tall and 2.5 to 3 feet wide. Although it can reach about 8 feet tall and 2 feet wide, with the help of pruning, gardeners can make it 6 feet tall and just 12 inches wide. 

• Stems: This shrub has woody stems that grow upright columnar. However, in the start, its stems are green, which turns grey-green to grey-brown after 2 to 3 years. The young stems are covered in fine hairs, while the mature stems become stiff and woody.

• Leaves: It produces dark green, small, shiny, and oval leaves that grow closely together. They are about 1 3/8 inches long and 3/4 inch wide. Unlike other holly shrubs, its leaves are not prickly, making them softer. However, the leaves can become darker in green color as they mature. 

• Flowers: It blooms with small greenish-white flowers in spring. Hence, as they grow, they can also produce tiny purple berries and black fruit, which attract birds.
• Fruits: This woody shrub produces small black berries on female plants from fall to winter. The berries are about 1/4 inch long and hidden under the leaves. However, a male plant is needed for pollination during this fruit-forming process. 

• Growth Habit: Sky Pencil Holly is a unique evergreen shrub that produces a narrow, column-like shape and grows in a tall and upright direction. 

• Growth Rate: It grows slowly to moderately and increases by 6–12 inches in height each year. However, it also maintains a narrow width as it grows taller.

Benefits of Using Sky Pencil Holly 

Sky Pencil Holly is a unique, low-maintenance shrub that offers multiple benefits. Here are a few of them:

• Low Maintenance: This shrub requires only minimal watering and pruning, making it ideal for gardeners with busy schedules. 
• Lush Foliage: Sky Pencil Holly has small, narrow, dark green, smooth leaves. Its dense evergreen foliage adds beauty throughout the year.
• Requires Less Water: This shrub needs little water and can survive dry conditions. Its deep roots help it tolerate droughts. 
• Urban Tolerance: It is a tough shrub that can handle pests and pollution, reducing the need for chemical treatments and making it easier to care for and maintain a healthier garden.
• Perfect for Landscape: Its tall, slim shape helps add height to small gardens and creates a natural privacy screen without taking up much space, making it ideal for landscape spaces. 
• Adaptable Growth: This woody shrub can grow in partial shade, making it a great choice for areas with less sunlight. It thrives in different light conditions, demonstrating its adaptability to multiple environments. 
• Attracts Wildlife: It attracts birds, bees, and butterflies and supports wildlife in the garden. In spring, female plants produce white flowers, which turn into black berries in the fall. They serve as food for birds, making them a wildlife-friendly shrub. 
• Versatility: The narrow shape of sky pencil holly makes it ideal for use as an accent plant, in containers, or as a border or hedge. However, the shrub also fits well in formal and casual garden style, making it a versatile holly.

Quick Tips to Plant Japanese Holly ‘Sky Pencil’

Here is a quick process for planting Sky Pencil Holly in the easiest way: 

• Choose large seedlings that are 2 years old for plantation. 
• Place the shrubs around 1 meter apart. 
• Ensure there are 1 to 1.2 meters between rows for proper air circulation and growth.
• After planting, gardeners need to gently press the soil around the roots and water well to help the roots settle into the soil.
• For the fruit production, both male and female shrubs are essential. 
• For good pollination, make sure the male and female plants are no more than 9 meters apart.
• One male plant can pollinate between 6 and 10 female plants, ensuring fruit production.

Sky Pencil Holly Plant Care Tips

Sky Pencil Holly is a low-maintenance shrub with a distinct columnar shape. To ensure it thrives, follow these care tips:

1. Water

This holly shrub needs less watering for healthier growth. It requires 0.8 cups of water every 9 days only when placed in direct sunlight and a deeper pot, such as in a 5-inch pot. However, in dry conditions, gardeners need to water them more often. 

It is important to water the plant regularly, but gardeners must ensure that the soil does not become too wet, which can lead to root rot. Hence, it is better to water only the shrubs when the soil is dry, especially for indoor plants. 

2. Soil 

This woody shrub can grow well in different soil types, like sandy, clay, or rocky soil. However, loose, well-drained soil works well for healthy growth. However, If the soil is clay or sand, gardeners can add to improve drainage and growing conditions. 

The shrub does not thrive in alkaline soils or dry conditions. Although it thrives in sun or partial shade and can grow in poor, sandy soil, it prefers clay.

3. Light

Sky Pencil Holly grows best in full sun but can also thrive in some afternoon shade in warmer areas. It needs at least six hours of morning sun daily for healthy growth. However, too little sunlight is also not good; if the shrub gets too little sun, it will grow slowly, and its branches will be less dense, resulting in no growth. 

4. Temperature and Humidity 

Sky Pencil Holly grows best in temperatures between 60–70°F (15–21°C) during the day and above 50°F (10°C) at night. It requires a moderate humidity level to stay healthy. Hence, gardeners can place it in a sheltered spot to protect it from strong winds. 

This shrub does not thrive in extreme heat, cold, or humidity. Hence, it is ideal for zones 6 to 8, where temperatures can reach as low as minus 10°F. In colder zone 5, with temperatures as low as minus 20°F, leaves may turn brown if they are not protected. 

5. Fertilizers

Sky Pencil Holly doesn't need fertilizer if it is planted in rich, organic soil. Even mulching the base works well for this woody shrub. However, gardeners can apply a balanced, slow-release fertilizer once a year in early spring for extra nutrients. 

There is no need for fertilization during the first growth year of the shrub holly. Gardeners can also add organic compost around the base to keep the growth. However, they need to avoid using high-nitrogen fertilizers, as they can cause weak growth and make the plant unhealthy.

Mulching 101: Benefits and Techniques for Healthier Gardens

Every gardener dreams of a lush and healthy garden. Mulching is an easy and successful way to achieve this. Gardeners can add a layer of organic materials or mulch to the soil, which offers many benefits for both soil and plants.

LEARN MORE →

Pruning Japanese Sky Pencil Holly Bushes

Pruning this plant is relatively simple due to its naturally compact and upright growth habit. Proper pruning ensures the shrub maintains its neat, columnar shape and stays healthy. Here is a step-by-step guide to prune Sky Pencil Holly bushes:

1. When to Prune

The best time to prune Sky Pencil Holly is in late winter or early spring before new growth starts. This helps the plant recover quickly and avoid cutting off new buds. It’s best to avoid pruning in the fall because new growth may not have time to harden before cold weather comes, which could harm the plant. Light pruning can also be done during the growing season if needed, but heavy pruning should be avoided.

2. Tools Required

• Pruning Shears: Use sharp, clean pruning shears or scissors to make precise cuts.
• Loppers: For thicker branches, loppers may be needed.
• Gloves: Wear gloves to protect the hands, as holly bushes have sharp leaves.

3. Identify What to Prune

When pruning, focus on cutting dead or damaged branches to keep the plant healthy. Remove overgrown or straggly branches that break the neat shape of the plant. Also, suckers (small shoots growing from the base) should be cut off, as they take energy away from the main plant. Look for any branches that cross each other or rub together, as they can cause damage.

4. Pruning Method

Sky Pencil Holly doesn’t need heavy pruning. Only lightly trim about 1–2 inches from the tips of the branches. Cut just above a leaf node (where leaves are attached to the stem) to encourage new growth. Try to keep the plant’s natural, tall, and narrow shape. If any branches grow out of this shape, trim them to keep the plant neat and upright.

5. After Pruning Care

After pruning, water the plant well to help it recover and encourage strong new growth. Growers can also refresh the mulch around the base of the plant to keep the soil moist and protect the roots. If gardeners haven’t fertilized yet, consider applying a slow-release fertilizer to support healthy growth for the season.

Propagating Sky Pencil Holly 

Sky Pencil Holly can be propagated through cuttings. This method is often preferred because it allows gardeners to grow a new plant that is genetically identical to the parent plant. Here's how to propagate Sky Pencil Holly:

• Choose a healthy, strong stem, about 4–6 inches long, ideally from a branch with fresh growth.
• Cut just below a node, where leaves meet the stem at a 45-degree angle, helping better root growth.
• Dip the cut end of the stem into the rooting hormone to improve the root development. 
• Plant the cutting in a hole in the soil about one inch deep. 
• Water the soil lightly and moisten it to improve the cutting and form roots.

Repotting Sky Pencil Holly

Sky Pencil Holly should be repotted every 2–3 years or when it outgrows its container. The best time to repot is during early spring before the plant starts its new growth. Avoid repotting in winter or during the hottest months, as this can stress the plant.

• Choose a pot that is a couple of inches larger than the current one, with drainage holes.
• For this, gardeners can choose terracotta pots because it helps to evaporate moisture. 
• Now, prepare a well-draining potting mix by adding perlite or sand. Compost can also work well. 
• Place a coffee filter or mesh at the bottom of the pot to stop soil from escaping through the drainage holes.
• Next, water the holly a day before repotting to remove the shrubs from its current easier pot.
• Gently remove the holly from the old pot. If it gets stuck, push or tape the sides to loosen it. However, be careful with the roots.
• Check the roots. If they are growing in circles, gently pull them apart. Cut off any dead or damaged roots.
• Now, place the shrub in the new pot, making sure it is at the same level as before. 
• Make sure that placed shrubs are not dipped deeper into the new pot.
• Fill the rest of the pot with soil, but make sure to pit gently.
• It is time to water the plant well, but don’t overwater.
• Put the newly potted holly in a bright spot and check the moisture regularly. 

Common Problems and Solutions of Sky Pencil Holly

Sky Pencil Holly is a hardy and low-maintenance shrub but can still face some challenges. Here are some common problems and their solutions:

1. Yellowing Leaves

Cause: Overwatering, underwatering, nutrient deficiencies, or incorrect soil pH.

Solution: 

• Make sure to check the soil moisture level. 
• If there is any need, adjust the watering schedule, and do not overwater it. 
• Ensure that soil pH is balanced or add fertilizers to address the nutrient deficiency. 

2. White Powdery Spots

Causes: Fungus issue. 

Solution: 

• Check the soil moisture and make sure it is not moist. 
• Improve the air circulation of this shrub by removing any fallen debris. 

3. Root Rot

Causes: Overwatering or poorly drained soil. 

Solution: 

• Remove the woody shrub gently and check its roots. 
• Cut out any root rots from the shrub. 
• Repot the cut roots into the fresh and well-draining soil. 

4. Brown Spots

Causes: Too much sun exposure, pest attack, fungus, improper watering, or poor soil drainage. 

Solution: 

• Move the shrub to a partial shade to protect it from extreme exposure to direct sunlight. 
• If there is any need, adjust the watering schedule and give proper water. 
• In case of a fungus attack, gardeners can use a fungicide to protect this woody holly shrub. 

5. Leaf Scorch

Causes: Too much exposure to sunlight. 

Solution: 

• Move the plant to a shaded area for better growth. 
• Or Add some sun protection during the daytime to avoid extra exposure. 

6. Curling Leaves

Causes: Overwatering or underwatering, too much sun exposure, high winds, and temperature changes.  

Solution: 

• Make sure to water the plant in a balanced manner. 

FAQs

Can Sky Pencil Holly be grown indoors?

Yes, Sky Pencil Holly can be grown indoors, but it requires specific conditions to thrive well, such as enough sunlight, moderate watering, and good drainage soil.

How fast does Sky Pencil Holly grow per year?

It is primarily a slow-growing woody shrub. It typically grows 6-12 inches per year, depending on the environmental conditions. 

What is the best place to plant Sky Pencil Holly?

It thrives in full sun to partial shade. Hence, placing it in a sheltered space is important to avoid extreme sunlight or temperature changes. 

The Bottom Line

Sky Pencil Holly is a unique, low-maintenance shrub that grows well with minimal water and partial shade. It is perfect for gardeners with busy schedules. The shrub has dark green, oval leaves, small greenish-white flowers, and blackberries that can add beauty to gardens or indoor spaces.

With the right planting, proper propagation, and regular pruning, Sky Pencil Holly can grow healthily for many years. Growcycle helps people select the right shrubs and houseplants, creating a healthier and cleaner environment.

Disclaimer: This material is for informational purposes only and should not be relied on for legal, medical, financial, or any other form of professional advice.

Sources:

1. thespruce - How to Grow and Care for Japanese Holly

2. bonsaiempire - Japanese holly Bonsai care and maintenance

About the Author

Victor Miller

Environmental Journalist Focused on Sustainable Agriculture

Victor Miller is an environmental journalist at Growcycle, where he covers the latest news, trends, and innovations in sustainable agriculture. He has a deep passion for storytelling that emphasizes ecological balance and responsible farming practices.

Before joining Growcycle, Victor worked for several agricultural and environmental publications, reporting on significant environmental issues and interviewing key figures in the sustainability sector. His work has been featured in various industry journals and online platforms.