Starting a New Perennial Garden

As the days begin getting longer and warmer, gardeners everywhere start thinking of planting. Planning and planting a perennial garden may take time, but will bring long-term rewards for the home gardener.

Inspiration

Gardens start with observation and inspiration. Two years ago, I was sitting on my deck on a summer afternoon, looking across the drive at the backdrop of our eight-foot hawthorn hedgerow with nothing but grass in front of it.  While the hedge is beautiful in the spring, covered in white blooms, and in the fall with red berries, it’s a little bland in summer.  And I thought – I need some color in front of that hedge.  While you can just jump in and start buying plants as soon as you have inspiration, it is both pleasurable and practical to take some time out and plan your garden.

Evaluate Site Conditions

First, evaluate the site conditions where you will locate your new bed. This will help guide your design and plant selections. Things like the amount of sun, shade, and wind at the site, how dry or damp the soil is, and how loose or compact the soil is will influence your design and plant selection. Are there other natural or man-made structures, such as shrubbery, sheds, or pathways, that need to be taken into account?  Perennial beds will seed and spread, so knowing what’s around the new bed and what access you need guides your design.  During your site evaluation, you may want to do a soil test. The makeup of your soil can significantly impact how well your plants will flourish.  Your local Penn State Extension office has soil test kits to purchase, with instructions on how to obtain a soil sample and a form to complete indicating what you want to do in the area (lawns, farm products, perennial garden, etc.). You mail the samples to the Agricultural Analytical Services Lab at Penn State University for analysis, and they return the results with recommendations on how to amend the soil for your stated use. 

In my example, the site gets full sun and is fairly well protected from wind. It is a large area (50 feet by 20 feet) and is backed by the previously mentioned high hedge on two sides and a post and rail fence on one side.  The hedge needs to be trimmed twice a year, which means we have to get a portable scaffold to it, have room to work, and collect and remove the trimmings.  I also needed to plan to maintain my new bed.  I wanted to maximize my garden impact while allowing for access and maintenance.  I finalized a layout that incorporated two corner beds and three circular beds evenly spaced between the corner beds. My design included allowing four feet between the back edges of the beds and the hedge, as well as 4-foot-wide paths between each bed.  When completely filled in, the circular beds will be eight feet in diameter, which allows me access to weed all around the perimeter while still reaching the center from a four-foot radius.

Purpose or Theme of the New Garden

Deciding on how you will use your new flower bed will help in plant selection and design.  Is this a cozy nook for sitting and reading, or a site you can see from a porch, deck, or a window from a room in your house?  Do you want to encourage pollinators and birds to frequent your garden?  Is this an area near where you sit outside or by an open window where you want fragrance day and evening?  My main goal was to provide myself with something colorful and beautiful to look at when I sit on my deck. But I also like to encourage butterflies and birds to visit my garden, and I already had an established pollinator bed between the two halves of the driveway that I wanted my new bed to complement. 

Planting Design Considerations

For the best impact, vary plant height, density, and bloom time.  Varying plant heights and layers in the bed provide visual interest and allow for a diverse selection for planting.  Selecting flowers that bloom at different times ensures beautiful color and texture all through the growing season. Your options for a color scheme are nearly infinite. A monochromatic color palette, or one that is limited to two or three complementary colors, is quite dramatic. On the other hand, a riot of colors adds fun and energy.  In my case, I wanted a riot of color and some significant height in the back of the beds to bring color up in front of the hedge. 

Another thing to consider is your climate or USDA Plant Hardiness Zone. Select plants that are hardy in your zone, otherwise, you will eventually find holes in your beds and you will be replacing plants that couldn’t survive. It is recommended that you select native plants for your region rather than non-natives. While you may be lured by flashy, non-native plants, many can become invasive. This leads to impeding the growth and health of the rest of the plants and endless hours of time trying to contain or eradicate the invader. At this stage, you may want to lay out the dimensions of the bed and the location and quantity of the various perennials you’ve selected.  This can be done by hand or by the use of garden or landscape planning software. 

Bed Preparation

Once you have completed the overall layout and plant selection, you will be ready to prepare the site for planting.  A thorough job of clearing turfgrass will save you hours of weeding in the future.  There are a variety of methods to achieve this.  Digging, plowing, and rototilling combined with raking out grass clumps is effective.  You can also solarize the area – cover the grassy area with plastic or newspaper and then cover this with a good layer of mulch.  After several weeks, the grass is dead, and the soil can be loosened and prepped for planting by digging or tilling.  This is also the time to amend your soil if needed.  In my case, I chose to simply lay a deep layer of shredded leaf mulch from our fall leaf cleanup over the grass, then rototill and rake in the spring.

Obtaining Plants

Armed with a general guide of the types of plants you want, you can get plants in several ways besides purchasing from your local garden center.  Local garden clubs and Master Gardeners often have plant sales with fun and unique plants. Swap plants with other gardeners when they are thinning out older beds or transplant from your own flower beds. (Make sure that your gardener friend does not have jumping worms.) In my case, I used all of the above options to begin filling my new beds.

With regard to quantities of plants to purchase, a perennial bed is most impactful when flowers are planted in mass groupings.  Keep in mind, perennials will propagate year after year.  If you let the flowers go to seed, new plants will grow the next year.  So, the least expensive way of starting a perennial bed is to buy one or two of each flower variety you want, plant them in the section of the bed you’ve selected, and let them spread on their own. This takes time and patience, but in three years, you will have the bed you’ve imagined. If you don’t have the patience to wait three years, you simply spend more time and money in your first year to achieve your goals. The downside to this is these perennials will continue to spread, and you will shortly find yourself having to thin out and divide your plants in order to prevent the bed from becoming overgrown.

Even with a general planting plan, once it’s time to plant, set out your plants still in the pots in the bed and rearrange them until you’re happy with the look. Follow the directions on the plant tags for the depth and width of holes to dig and the spacing between plants. Place supports for flowers that will need them when you plant so you can attach them to the support as they grow.  Once everything is planted, place a layer of mulch (2 to 3 inches) to help keep weeds out and moisture in. It is important to water at least daily for a week after planting so the root systems get well established.

Sit back, relax, and enjoy watching your new perennial bed blossom.