A Garden from Scratch: How to Begin the Plant Selection Process

You’d think choosing plants was easy enough—just find the ones you like, right? And for single specimens in a pot or a monoculture of, say. roses or hydrangeas, it is as simple as that.

But what about designing a border where plants need to relate to each other in a well-thought-out design? And what if you have a large blank canvas to fill with a whole range of plants. This is when it can get a little more complicated. For the third post in my column on creating A Garden From Scratch, I tackle how to figure out the kind of plants you might want in your landscape. Before you get too excited, let me clarify that I’m not talking about choosing specific plants here; this is about the bigger, long-term picture of how to put plants together in a space and why.

(To read my earlier stories in the Garden from Scratch series, go here, then here.)

Photography by Clare Coulson.

1. Get trees in first.

Planting design is about a series of layers, from the woody plants, including trees and climbers, to the shrubs, herbaceous perennials, biennials, and annuals. Most gardens will have a mix of all of these types of plants to create a succession of interest throughout the year, and a balance of structural plants that will provide a backdrop to herbaceous plants that will flower and die back.

It’s logical to begin with the trees since they generally need the most time to mature. They are also arguably the most important thing to get right, being the least ephemeral. Incorporating some trees, or even a single specimen, can instantly ground a space, bringing strong structure, height, and impact—as well as, in many cases, year-round interest. For this same reason think very carefully before removing any mature trees or shrubs from an inherited space.

It’s the one place perhaps where it’s worth spending some money to buy something really beautiful—a trio of Amelanchier or Prunus multi-stem or specimen trees, for example, may feel like a big investment, but it will have instant impact, as well as blossoms in spring, lush foliage through summer, and then great leaf color later in the year. In winter its form has its own allure. Tip: Buy young trees—they are far more economical and will usually settle in faster than mature specimens. Buying bareroot plants also helps to keep down costs.

2. Invest in evergreens.

Another worthwhile investment: evergreen forms that will provide four-season structure. Boxwood would have ticked all the boxes, but now that these are under the dual threat of box blight and box caterpillar, few gardeners would take a risk with them. There are plenty of alternatives—yew, Ilex crenata, many pittosporums, rosemary, hebes, daphnes can all be grown into shapes that will provide permanent year-round forms and act as a foil to herbaceous plants. Deciduous plants like beech and hornbeam can also provide structure, too. (See Landscaping 101: Boxed in by Boxwood? 5 Shrubs to Try Instead.)

3. Focus on forms.

When it comes to flowers, think about their forms and how they will work together in a space. While I’d be more than happy with a peachy sea of ‘Sutton’s Apricot’ foxgloves and nothing else, in reality a border generally consists of contrasting forms. Spires, including foxgloves, delphiniums, veronicastrums, verbasums, and lupins, either planted in groups or dotted about, bring strong verticals. Other perennials provide a mound of dot-line flowers—think knautia, scabious, or rudbeckias. Umbellifers bring elegant saucer-shaped flowers at different heights from tall (valerian, fennel, eupatorium) to short (achillea or anthriscus). Other plants provide neat mounds of foliage and flowers or an airy veil that associates well with other plants.

4. Embrace star plants.

Some plants may be ubiquitous—but that’s normally for good reason. Stalwart plants can be the star players in your borders—Nepeta racemosa ‘Walker’s Low’, Geranium ‘Rozanne’, Alchemilla mollis, Calamagrostis x acutiflora ‘Karl Foerster’—are a few of the thousands of plants awarded the RHS’s Award of Garden Merit because they are tried and tested resilient plants that will perform well in a garden setting. Any plants that will flower for a long season, provide you with beautiful foliage when the flowers are long gone, or produce beautiful seedheads to stand through winter are all worth considering for your borders.

5. Consider the plant’s pre and post-bloom appearance.

The shape of plants, their foliage, and leaf shape is often more important than the flowers that come and go. The indigo spires of Baptisia australis may be gorgeous, but they are fleeting, while their mound of lush foliage and sculptural pods provide interest way beyond summer. Many euphorbia varieties are highly valued for their zingy lime flower heads in spring, but when those stems are cut back at the end of flowering the plant’s glaucous mound of foliage provides a great foil to summer flowers. When the lime flowers or Alchemilla mollis go over, a mound of toothed velvety leaves remain. Low mounds of foliage can also help conceal other plants as they die back—the delicate mounds of foliage from hardy geraniums are perfect for covering up the leaves of spring bulbs as they die back.

6. Shoot for a long season of interest.

My priority in creating any border is that it has as long a season of interest as possible, preferably year-round. This takes some considerable planning as you will need to orchestrate a group of plants that will not only work harmoniously but also provide something to admire. whatever the season. Some plants may just do one thing—but in your collection, ideally, you want plants that do multiple things—trees and shrubs that give blossom, good foliage, and great autumn color; perennials that can be cut back and will produce a new flush of foliage and flowers a few weeks later. To extend the season further, you can add a collection of spring bulbs that will flower while many plants are just filling out with fresh spring foliage. If you can achieve all this, while also selecting plants that will hold their form through winter, then you have arguably hit the garden design jackpot.

See also:

• DIY Decorating with Dried Alliums, Your Garden’s Readymade Baubles
• Lessons Learned: Ornamental Grasses at Five Acre Barn
• September in the Garden: 8 Ways to Stretch the Season