The globe cedar, a delightful spherical evergreen (Thuja occidentalis ‘Globosa’), is a popular choice for its compact form and vibrant green foliage, making it ideal for hedges, borders, or as a standalone specimen. Its consistent, neatly rounded shape requires little to no pruning, offering an effortless aesthetic to any landscape. However, achieving this effortless beauty hinges significantly on one critical decision: when to plant it. Proper planting time is paramount for the health and long-term establishment of any evergreen, and the globe cedar is no exception. This article will delve into the optimal periods for planting your globe cedar, exploring the benefits of spring and fall, and discussing why other seasons might present challenges, ensuring your new addition thrives for years to come.
Understanding the globe cedar
The globe cedar is a cultivar of the native North American white cedar (Thuja occidentalis), known for its distinctive dense, globose growth habit. It typically matures to a height and width of 4-5 feet, offering year-round interest with its rich green, scale-like needles. This evergreen is generally hardy in USDA Zones 3-7, making it suitable for a wide range of climates. Like all evergreens, globe cedars continue to respire and transpire throughout the winter months, albeit at a reduced rate. This continuous physiological activity means their root systems need to be well-established before facing periods of environmental stress, whether it’s the intense heat and potential drought of summer or the freezing temperatures and desiccation of winter. Planting at the right time significantly reduces transplant shock and gives the plant the best chance to develop a robust root system capable of supporting its above-ground needs.
The prime planting seasons: Spring and fall
For globe cedars, two seasons stand out as ideal for planting: spring and early fall. These periods offer a perfect balance of favorable environmental conditions that promote strong root development without imposing undue stress on the plant.
Spring planting: As the last threat of hard frost passes and the soil begins to warm, spring presents an excellent window for planting. The soil is typically moist from winter snowmelt and spring rains, providing ample hydration for new roots. The cooler air temperatures, coupled with warming soil, encourage root growth before the plant has to contend with the intense heat of summer. This allows the globe cedar several months to settle into its new home and establish a root system before the most challenging growing conditions arrive. Consistent moisture is generally available, reducing the need for constant supplemental watering, although monitoring is always crucial.
Early fall planting: Often considered the best time by many horticulturalists, early fall provides another prime opportunity. At this time, air temperatures are beginning to cool, reducing transpiration rates and overall stress on the plant. Crucially, the soil retains much of its summer warmth, which is vital for root growth. This combination allows the roots to grow actively for several weeks, or even months, before the ground freezes solid for winter. The cooler, often moister, conditions mean less frequent watering is needed compared to summer planting, and the plant can dedicate its energy to root development rather than maintaining foliage in hot weather. By the time winter truly sets in, the globe cedar will have had a significant head start in establishing itself, making it more resilient to winter conditions.
Navigating challenging planting times
While spring and early fall are preferred, sometimes planting must occur outside these optimal windows. Understanding the risks and implementing mitigating strategies is crucial.
Summer planting: Planting globe cedars in the peak of summer, particularly during hot and dry spells, is generally discouraged due to the high risk of transplant shock. High temperatures and intense sunlight demand excessive water from the plant, which newly developing roots may struggle to supply. This can lead to wilting, scorching, and even death. If summer planting is unavoidable, choose an overcast day, provide immediate and thorough watering, and consider temporary shading for the first few weeks. Consistent, deep watering daily or every other day will be critical to its survival.
Winter planting: Planting globe cedars when the ground is frozen or during harsh winter conditions is also highly risky. Frozen soil prevents root growth and makes digging difficult, if not impossible. Even if the ground isn’t fully frozen in milder zones, cold winds can cause desiccation (drying out) in evergreens, as their leaves continue to lose moisture while the frozen roots cannot replenish it. While container-grown plants can technically be planted in winter if the soil is workable, it’s generally not recommended unless you are in a very mild climate and can guarantee consistent soil moisture and protection from harsh winds. The lack of root activity in cold soil significantly hinders establishment, making the plant highly vulnerable to winter injury.
Here is a summary of planting considerations by season:
| Season | Pros | Cons | Recommendation |
|---|---|---|---|
| Spring | Warming soil, consistent moisture, long growing season for roots. | Potential for late frosts, competition with spring weeds. | Excellent, highly recommended. |
| Early Fall | Cooler air, warm soil, good moisture, reduced plant stress. | Shorter period for root establishment before winter. | Excellent, often considered optimal. |
| Summer | None for new planting, only if absolutely necessary. | High heat stress, drought risk, constant watering required. | Avoid if possible; requires intensive aftercare. |
| Winter | None for new planting in most climates. | Frozen ground, no root growth, desiccation risk from winds. | Strongly avoid; very low success rate. |
Beyond timing: Essential factors for success
While optimal timing is fundamental, the ultimate success of your globe cedar also depends on proper planting techniques and ongoing care. Here are crucial factors to consider:
- Soil preparation: Globe cedars thrive in well-drained soil rich in organic matter. Amend heavy clay soils with compost or other organic materials to improve drainage and aeration. For sandy soils, organic matter will help retain moisture and nutrients. Aim for a slightly acidic to neutral pH (6.0-7.0).
- Sunlight requirements: These evergreens perform best in full sun to partial shade, meaning at least 6 hours of direct sunlight per day. While they can tolerate some shade, too little light can lead to thinner foliage and a less dense, less vigorous plant.
- Watering: Consistent moisture is vital, especially during the first year of establishment. Water deeply and regularly, ensuring the soil is moist but not waterlogged. Check the soil moisture by hand – if the top few inches are dry, it’s time to water. Reduce frequency as the plant establishes, but never allow it to completely dry out.
- Mulching: Apply a 2-3 inch layer of organic mulch, such as shredded bark or wood chips, around the base of the plant. Keep the mulch a few inches away from the trunk to prevent moisture buildup and potential rot. Mulch helps retain soil moisture, regulate soil temperature, suppress weeds, and slowly adds organic matter to the soil as it decomposes.
- Planting depth: Dig a hole that is twice as wide as the root ball and just as deep. The top of the root ball should be level with the surrounding soil surface. Planting too deep can suffocate the roots, while planting too shallow can expose them to drying out.
Planting a globe cedar at the right time is perhaps the most significant step you can take to ensure its health and vigorous growth in your landscape. While spring and early fall offer the ideal conditions for root establishment, understanding the challenges of summer and winter planting can help you mitigate risks if those times are unavoidable. Beyond the calendar, remember that proper soil preparation, adequate sunlight, consistent watering, and thoughtful mulching form the bedrock of a thriving evergreen. By combining optimal timing with diligent care, you are not just planting a globe cedar; you are investing in a beautiful, low-maintenance landscape feature that will provide year-round enjoyment and curb appeal. Your efforts in the beginning will be amply rewarded with a healthy, vibrant plant for many years to come.
Image by: Akshay Janjire