Perennial borders, which are often referred to as herbaceous borders, originated in Britain and were typically placed in front of fences, hedges, or walls, often on the property’s boundaries, usually in rectangular shapes.
When creating your new border, it’s essential to ensure it harmonizes with your overall garden design. In more relaxed and informal landscapes, curved borders and island beds may be a better fit.
On the other hand, in formal gardens characterized by geometric principles and straight lines, rectangular beds tend to complement the aesthetic. Here are 6 steps that will help you out:
Step 1: Conduct a Site Inspection
The first step you should follow is to choose the right location for a perennial border. For first-time attempts, I recommend choosing a flat site with a minimum of six hours of direct sunlight daily.
Most perennials thrive in sunny conditions, giving you a broader selection of plants to work with. It’s also wise to avoid planting near mature trees, as young perennials often struggle to compete with these large trees for sunlight, water, and nutrients.
If your new border can be viewed from a prominent window in your home or an outdoor seating area, that’s a bonus.
Also, you want to consider the soil. Is it typically wet or dry? Is it predominantly clay, sandy, or somewhere in between? Soils at the extreme ends of the spectrum – mostly clay or mostly sand – can be improved by incorporating ample organic matter, like leaf mold, composted manure, and your homemade compost.
Persistent soggy soil is not favorable for most perennials. If your chosen area has this issue, you can enhance drainage by using perforated plastic pipe (weeping tile) to divert excess water, raise the planting area, or explore other location options.
Step 2: Visualize the Area Where Your Border Will Be
To prepare your perennial border, visualize the area and use string and stakes for rectangular beds or a rubber hose for curved ones. A typical width is about six to seven feet, allowing easy access for maintenance.
If it’s against a wall, leave an 18-inch pathway. Wider beds, around eight to 10 feet, offer more plant height options but require pathways or flat stones for access.
Removing turfgrass is often necessary. You can smother it with newspaper and plastic (slow), or slice it off with a spade (faster). Use the removed turf to patch bare lawn spots or compost it.
Step 3: Enhance Your Soil
To ensure a strong start, begin by enhancing and nourishing your soil, regardless of its type, before introducing plants. The concept of “fat soil” describes nutrient-rich earth teeming with beneficial organisms.
Fattening up your soil involves adding organic matter like compost, composted manure, or leaf mold. Apply approximately four inches (10 cm) of organic matter onto the soil’s surface and use a garden fork to incorporate it into the top two or three inches (5 to 8 cm) of the garden soil.
If you’re working on a larger border, this may require a significant amount of compost, so consider buying it in bulk from a nursery, landscaping company, or farmers. Allow newly prepared beds to settle for a week or two before planting.
Step 4: Create a Focal Point
Perennial borders often benefit from permanent features like birdbaths, birdhouses, sculptures, and plant supports. However, be mindful not to overdo it; too many non-plant elements can clutter the space.
To maintain a natural look, avoid abrupt endings by using existing walls, fences, shrub groups, or evergreens to define the border’s edges. While large rocks can help, don’t go overboard and create a “Flintstones” look.
Step 5: Pick the Right Plants
Before heading to the nursery, it’s wise to do some research and have a plant list in mind. Impulse buying isn’t recommended in gardening. Many exceptional long-lived perennials may not look impressive in pots at the store, and some, like echinacea and monkshood, may seem insignificant in spring but shine in late summer and early fall.
You want to plan for a mix of spring, summer, and fall-blooming perennials to keep your border interesting year-round.
Look for a reputable nursery for healthy, well-grown plants. Avoid plants from neighborhood sales or well-meaning friends and relatives, as they can be invasive and carry unwanted pests and diseases. Opt for plants that require less frequent division.
Consider adding shrubs and vines with showy flowers or colorful foliage for height and interest. Avoid planting species with similar-looking foliage side by side. A great perennial border should always look appealing due to its attractive, contrasting foliage, even without flowers in bloom. Spring bulbs can add early-season color but remember that their foliage takes time to mature, so plan accordingly.
Whether you prefer a riot of color or a color scheme, plant in drifts (groups of three, five, or seven perennials) to avoid a patchwork look. Single specimen plants with unique forms or leaf colors can serve as accents within the border.
Vary plant heights to create dynamic displays by mixing low growers with taller ones for a more interesting visual composition.
Step 6: Start Planting
The final step of the process is straightforward and enjoyable. On an overcast day, place the plants in their pots on the soil surface, considering their eventual width at maturity, and group similar plants together in drifts. This step may take a few hours, involve some back and forth, and perhaps a glass of wine or two.
Once everything is arranged to your liking (for now), you can start digging the planting holes. Add extra organic matter to the hole’s bottom and sides while blending it with the native soil.
Plant the perennials at the same depth as they were in their pots, press them firmly into the soil, and water thoroughly. You won’t need transplanting solutions if you’ve incorporated enough organic matter into your soil.
After planting all the perennials, cover the exposed soil with a three-inch (8-cm) layer of organic mulch to retain moisture and deter weeds. Water the perennials regularly during dry spells until they are well established, and enjoy a continuous display of flowers each year.