Layered Planting

Earl Nickel,
Curious Plantsman

Many Bay Area gardeners are working with small spaces, where it can be a challenge to find room each season for all the new plant varieties we want to try and grow. It turns out there’s an easy and nifty method for maximizing smaller spaces called layered planting. You may already be familiar with the idea of layering in beds, with ground cover plants in front, then a slightly taller plant behind it and finally a shrub or taller perennial in the rear. Layered planting uses that same principle but applies it vertically to a single small space and it works like this – one or more bulbs under the surface, a ground cover or short plant directly above and then a taller plant in that same space.

Initially, your bed will have the shorter plant – it is best to choose somewhat airy plants for this purpose – and possibly the taller plant planted in the space at the same time (though this can be added later). Then, in spring or summer, the bulb(s) you’ve planted in the ground will surface, pushing up through the shorter plant above it. This layered planting mimics nature, where bulbs or corms naturally push their way up through the plants above them. Most bulbs bloom for a 2-month period and then they’re done for the year. But during this time, you have a dense and wonderfully floriferous planting in a very small area. After they’ve finished blooming, you can fold their leaves down to the ground and rubber band them to keep them in place, until they naturally yellow. At this point, they’ve finished putting nutrition back into the bulb and the leaves can be cut off.

Choosing the Plants

Bulbs

Gladiolus carneus and Glaucium grandiflorum

Although early season bulbs such as daffodils and tulips should already be planted, there are many late spring or summer bulbs left to use in our layered planting scheme. Harlequin flower (Sparaxis) offers a multitude of dazzling colors and has the added benefit of naturalizing in your garden. Annie’s grows two fabulous ones – S. elegans and S. tricolor. One of the most popular spring bulbs is Freesia. Easy to grow and quick to naturalize, they come in a variety of splendid colors. Plus they are possibly the most fragrant bulb ever! All of which means that they are one of the most ideal bulbs for a layered planting scheme. Dutch or Japanese iris are showy bulbs that return every year, with the Dutch iris flowers showcasing purples, gingers, yellows and white while the Japanese species display a range of purple and lavender shades. Gladiolas are another early summer bulb that adds a handsome vertical element, whether you choose the species kind, such as the pretty G. carneus ‘Painted Lady’ or one of the great many hybrids.

For a lower growing bulb, I recommend several varieties of the California native Blue-Eyed grass (Sisyrinchium). S. ‘Devon Skies’ produces exceptionally lovely, one inch purple flowers from late spring through the end of summer. Only 6” tall but slowly spreading to one foot across, it can also be used as a low plant in this layered planting scheme. Sisyrinchium ‘Quaint & Queer’ meanwhile boasts colors that range from mauve and maroon to chocolate and apricot, with pretty yellow ‘eyes’. Both varieties are easy to grow, deer and rabbit resistant and attract butterflies and beneficial insects.

Low Growing Selections

For those plants that you want to stay low, there are three groups – ground covers, low annuals and prostrate perennials. One of the best ground covers is Sun Rose (Helianthemum). Annie’s offers, Helianthemum ‘Belgravia Rose’, which produces a mass of pink-splashed, one-inch flowers that resemble small single form roses. These cheerful blooms seem to float on a bed of small grayish-green leaves that hug the ground but can each spread out to cover a three-foot area. Tough as nails, drought tolerant, and evergreen, it makes the perfect ground cover for a sunny spot.

One of the prettiest ground covers you’ll ever grow is the lush green ‘Little Ears’ (Falkia repens). Hailing from South Africa, it forms a dense mat of 1” glossy green leaves that are lightly cupped, and in summer, sprouts a bevy of small white flowers that bees dig. It likes a little regular water but isn’t thirsty and makes the perfect green understory for taller plants.

For something a bit different, how about selecting a strawberry as a ground cover? The remarkably vigorous Dutch hybrid ‘Elan’ strawberry is extra sweet due to a high sugar content and contains 30-50% more vitamin C than other everbearing strawberries. It fruits spring through fall with many runners, allowing it to spread out and be especially prolific.

 For a beautiful low-growing annual, how about California poppies? Annie’s offers a dazzling selection, from the clean white flowers of Eschscholzia ‘Alba’ through the color spectrum of golds (‘Golden Chiffon’), peachy tones (‘Apricot Chiffon’), vibrant reds (‘Red Glow’), rich pinks (‘Rose Chiffon’) and even a pinkish-purple (‘Purple Gleam’). California poppies are easy to grow, and they have a loose habit, making it easy for bulbs to push up through. They also often self-seed. They’re stingy on water too.

Dianthus ‘Thea Mary’ & Geranium ‘Rozanne ‘

Two perennial options are Dianthus (“Carnations”) and Geraniums. Dianthus species or varieties are incredibly tough and long blooming, Lovely white-flowering varieties include ‘Hercules’, ‘First Scent Coconut’ and ‘Georgia Peach Pie.’ Or, if pink is your thing, then ‘Electra’ and ‘Bumbleberry Pie’ are fabulous additions. Most “Carnations” form a low mat of bluish-green, fine-textured foliage, with the flowers thrust above.

Three Geraniums make our ‘beautiful but ever so useful for layering’ list. G. pyreniacum ‘Bill Wallis’ has lacy foliage 10-20” tall and wide, with small but beautiful purple flowers, while G. ‘Orion’ has larger (2”) bluish-purple flowers and a loose foliage habit. Geranium ‘Rozanne’ is so popular we can hardly grow enough of it. Lovely bluish-purple flowers smother the plant all summer long, inviting regular visits by bees and butterflies. All three selections are drought tolerant, with little care required.

Taller Selections

Veronica longifolia , Geranium ‘Rozanne’ & Agrostemma g. ‘Milas’

For the taller selections, you’ll want to choose plants that possess a vertical stature but also display an airier habit. This allows the bulbs and lower plants in your layered spot to get enough light and air circulation. There are many annuals to choose from but 3 easy and beautiful options are Agrostemma, Cynoglossum and Phacelia. “Corncockle” (Agrostemma) is an English garden favorite and one look at its satiny pink or pure white flowers will make you swoon. The 2” flowers sit atop swaying two foot stems, providing a perfect (way) to add verticality to any sunny spot. “Chinese Forget-Me-Not” (Cynoglossum amabile) meanwhile offers up an endless parade of robin’s egg blue flowers, blanketing the upper portions of a 3′ high multi-branching plant. The simple half inch, 5-petaled flowers on this tall forget-me-not will indeed stick in your memory long after it’s done blooming. If darker blue flowers are your thing, Sticky Phacelia (Phacelia viscida) offers intense, Gentian blue flowers from mid spring through early summer. This California native also has a multi-branching form, growing to 30” x 30”. The saturated blue 1” flowers also feature an intricately patterned center nectary, making it one of the prettiest flowers you will ever grow.

Three perennial selections are led by the many types of taller Speedwell (Veronica). Whether you’re choosing Spike Speedwell (Veronica ‘Perfectly Picasso’ or Veronica ‘Purpleicious’) or Garden Speedwell (Veronica longifolia ‘Bushy Boy’), these purple flowering beauties add hummingbird friendly pizzazz to any location. Ranging in height from 2-3′, their multitude of flower spike-tipped branches and vibrant green leaves offer a bit of (purple) heaven.

Sidalcea malviflora ‘Purpetta’ & Agrostemma ‘Ocean Pearls’

 Where the speedwell offers lavender-like flower spikes, Checkermallow (Sidalcea malviflora ‘Purpetta’) displays round and ever so rosy-pink flowers to the lucky gardener who finds a place for this bee and butterfly plant. Related to hollyhocks and other mallows, this 4′ tall perennial is a long blooming and carefree plant to grow. Though a bit shorter, Henderson’s Checkermallow offers the same cheerful open-face pink flowers, on straight as an arrow upright stems.

Finally, there is the aptly named Blue Milkweed (Tweedia caerulea ‘Heaven Born’). Related to the milkweed that is the host plant for Monarch butterflies (Asclepias speciosa or A. fascicularis), this hardy, often evergreen perennial produces the dreamiest star-shaped blue flowers imaginable! It blooms nonstop from early summer through fall and is a food source for many kinds of local butterflies. It takes a mostly vertical form, though its slender branches may wander a bit. It’s all part of the charm of this unique beauty.

Layered Beauty

The great thing about layered planting is that you can choose any number of plants to achieve this effect. Annie’s has new plants coming available every week so gardeners will have endless choices for fashioning their own miniature artistic statements!