Winter may still have its grip on the landscape, but it’s the perfect time to start planning for the spring gardening season. Paul Zimmerman, a renowned garden designer and author, shares his expertise on getting gardens ready for the vibrant season ahead. From identifying the right timing to essential soil care, pruning, and fertilization, Zimmerman’s advice sets the stage for a thriving garden. Follow along with the original video here:
When to Begin Spring Preparations
The first step to successful spring gardening is knowing when to start. Timing can vary depending on location and climate. Zimmerman highlights the importance of local cues, such as the blooming of forsythia—those bright yellow flowers that often signal the end of dormancy. For gardeners without forsythia, he recommends finding your region’s last frost date using online resources. Simply count back six weeks from that date to determine when to start your preparations.
For example, in Zimmerman’s home in upstate South Carolina, the last frost date is around April 15th, so spring prep begins in late February or early March. In regions without a pronounced dormant season, January is a suitable time to start these tasks.
The Foundation of a Healthy Garden: Soil Preparation
Zimmerman emphasizes that soil is the cornerstone of a flourishing garden. Winter provides an excellent opportunity to assess and amend it. Here’s how to get started:
Checking Soil pH
Most roses prefer a slightly neutral pH, around 6.5 to 7.0. In areas with acidic soils or after heavy rains, pH levels may dip below this range. Zimmerman suggests using a simple soil meter to test multiple spots in the garden and adjust as needed with amendments like lime.
Soil Testing for Nutrient Balance
Beyond pH, a professional soil test offers invaluable insight into nutrient deficiencies or imbalances. Agricultural extension offices or universities with horticultural programs can perform these tests for a modest fee, providing a roadmap for amendments tailored to your garden’s needs.
Why Soil Health Matters
Healthy soil is more than just a growing medium—it’s a living ecosystem. Beneficial microbes, fungi, and earthworms work together to break down organic matter, releasing nutrients that plants can absorb. By maintaining proper pH and nutrient levels, you create an environment where this microbial life thrives, ensuring long-term fertility and plant health.
Pruning and Cleaning: The Key Early Tasks
Once the timing is right, Zimmerman advises starting with pruning and cleanup:
Pruning Roses and Perennials
Pruning roses is an essential spring task, tailored to each type of rose. For shrub roses, the focus is on removing dead or crossing canes to improve airflow and reduce disease risk. For climbers, selective pruning encourages healthy new growth while training canes horizontally to maximize flower production. Waiting until six weeks before the last frost date ensures that dormancy has ended and the plants are ready to respond to pruning.
Perennials, Zimmerman notes, should be cut back when new growth appears in the spring. This approach preserves the winter shelter for beneficial insects overwintering in the old foliage, a practice increasingly favored by ecologically mindful gardeners.
Cleaning Up Debris
Removing fallen leaves, sticks, and other debris clears the way for new growth. However, Zimmerman makes an exception for hardwood leaves, which can break down into natural compost under mulch, enriching the soil. He cautions against leaving debris directly on top of emerging perennials, as it can suppress their growth.
Mulching and Soil Conditioning
Mulch serves as both a protective layer and a soil conditioner, and Zimmerman recommends applying it only after necessary amendments.
Types of Mulch and Their Benefits
Different mulches serve different purposes. Fine bark mulch is ideal for weed suppression and maintaining even soil temperatures, while composted mulches add nutrients over time. For roses, a 2–3 inch layer of mulch is typically sufficient. However, it’s important to avoid piling mulch against rose stems, as this can lead to rot.
Preparing the Soil Before Mulching
Before laying down mulch, Zimmerman advises applying any necessary soil conditioners, such as lime, alfalfa pellets, or other amendments identified by your soil test. These adjustments ensure that the soil is in prime condition to support the growing season.
Fertilizing Roses: Timing Is Key
One of the most common questions Zimmerman encounters is when to start fertilizing in spring. His advice? Let the roses guide you. Fertilize when the first true set of leaves emerges, signaling active growth. True leaves look distinctly different from initial bud swelling and indicate the plant is ready to absorb nutrients.
At this stage, gardeners can begin their regular feeding program, whether that involves granular fertilizers, sprays, or organic amendments.
Wrapping Up Spring Preparations
Spring preparation isn’t just a chore—it’s an investment in the garden’s success. By following these steps, gardeners can set the stage for a vibrant, healthy growing season:
- Test and amend soil to ensure optimal pH and nutrient levels.
- Prune roses and cut back perennials once new growth appears.
- Clean up debris, leaving beneficial organic matter where appropriate.
- Apply soil conditioners before mulching.
- Mulch the garden with a protective layer of organic material.
- Fertilize roses when the first true leaves appear.
Paul Zimmerman’s expert advice simplifies what can often feel like an overwhelming process, ensuring your garden is primed for success. As he reminds us, preparation now leads to the “roaring spring flowering” we all look forward to seeing.
Zimmerman’s guidance offers a step-by-step approach to spring gardening, empowering gardeners of all levels to embrace the season with confidence. With these insights, your garden will be ready to flourish, rewarding your efforts with lush blooms and vibrant growth.
Paul Zimmerman is the founder of Paul Zimmerman Roses, dedicated to the philosophy that “Roses Are Plants, Too.” With decades of hands-on experience, Paul specializes in all kinds of roses but particularly antique, shrub, and David Austin roses. A sought-after designer, consultant and educator, he designs sustainable rose gardens for private clients and public institutions both in person and virtually
