Late Summer Gardens, Part I

For summer dry gardens, August begins to separate the fabulous gardens from the rest. It’s relatively easy to make a garden gorgeous in the late winter, spring, and early summer. There are a multitude of plants to choose from, all of which thrive in the cool moist soils and sunny warm days between rains. But by August, our foggy season is well advanced, and plants have already suffered through weeks of cool moist air and warm dry soil. This is the opposite of what most plants need. And there’s nothing ahead but more of the same.

Most San Francisco gardens have a big let-down at this time of year, when unhealthy plants and spent flowers compete visually with the few that are still blooming. But there are a few simple tricks of the trade which will allow you to rejuvenate your garden this August, and allow you to look forward to the late summer and fall garden in future years.

First and foremost, good garden design calls for a sequence of bloom, with new plants coming into their first flush of bloom in each season. There are not as many choices in summer dry gardens of plants just now starting to bloom, but the ones we have can be spectacular. Here are a few choice plants that are coming into bloom now at Garden for the Environment, helping us keep the foggy doldrums away.

Glossy abelia (Abelia grandiflora) is a graceful, arching shrub with an open habit. Its shiny foliage has a reddish cast at the growing tips, which echoes the burgundy bracts holding the pendulous pink flowers. A tough performer, Abelia can take quite a bit of shade and dryness and still look lovely at this time of year as it begins to bloom. The arching shape of this plant can be maintained by pruning out one-third of the oldest canes each year, cutting them right down to the ground, to stimulate new canes breaking out at the base.

Abelia grandiflora.

Lion’s tail (Leonotis leonurus) is a big, strong upright shrub and a vertical accent in the back of the border. It is just now beginning to open its dramatic, fuzzy orange flowers which grow in whorls up each vigorous stem. A big bright statement for late summer and fall, lion’s tail also attracts hummingbirds and butterflies.

Many different sages (salvias) from the littlest groundcover to eight-foot shrubs covered with bright flowers are either in full bloom or just now starting at GFE. My personal favorite is Salvia mexicana ‘Limelight’ which is at its best now, with bright blue tubular flowers blooming out of lime-green bracts, a dramatic color combo that explodes visually. Like other salvias, this one attracts hummingbirds.

Salvia mexicana ‘Limelight.’

Here is the big challenge for summer-dry gardeners at this time of year. It is a terrible time to buy and plant new plants, but now is the time nurseries have late-summer blooming plants in stock. Ideally, planting time for summer-dry gardens is in fall, when soils are still warm but the first rains are falling. Second best is early spring, with several rainy months still ahead. The worst possible time is now, with soils completely dried out and several months ahead without rain. As a result, many home gardeners have gardens well stocked with winter and spring blooming plants and very few late summer/fall blooming plants that have survived from previous years.

Even plants that are well-suited to dry summer soils can’t survive if planted from a container into a dry garden when in full bloom. So to get late summer blooming plants established requires extra attention from the gardener. If you plant a beautifully blooming sage this week or next, it will need a generous planting hole, several times the size of the root ball of your new plant. The hole should be amended and watered so there is improved, moist soil all around and under the new plant’s roots. Your newly-planted youngster will need plenty of extra watering this summer. A plant that usually prefers a dryish soil and performs best with weekly watering or less, may need to be watered every day or every other day, just for this first summer. After several weeks you can begin letting the plant go a little drier between watering, but do not let it wilt. The extra effort now will reward you with a plant that will thrive and surprise your garden with late summer bloom for years to come.

Having the right plants in your garden for late summer color is only half the battle. The other half is tidying up the parts of the garden which were so lovely a few months ago. Many older San Francisco gardens feature camellias, rhododendrons, and azaleas, all of which may be covered with faded, brown flowers at this time of year. Even gardens with a more modern plant palette probably have many plants covered with spent flowers. Deadheading, or cutting off the faded flowers, is an important part of garden care at this time of year.

We grow ornamental garden plants for the beauty of the blossoms. But for the plant, the blossoms are just a means to an end. They attract pollinators with their colors and fragrance, and once the flowers fade, the serious business of ripening seeds begins. Most of your plant’s energy at this time of year is going into the seeds, unless you remove the faded flowers to prevent seed formation. If you do so, the plant will put its extra energy into other tasks such a growing a stronger root system, a sturdier immune system to fight off pests and diseases, storing energy in woody tissue, and last, but not least, into forming buds for next year’s flowers.

You will also be glad you did from a visual perspective. Deadheading can be tedious, but when you step back and see your newly groomed plants, it will be just as though you washed their faces and combed their hair. They will look sweetly fresh, and instead of distracting the eye with their forlorn disheveled look, they will step into the background and allow other parts of the garden that are lovely now to step forward.

Even with the fog and dry soils, our summer gardens can be beautiful and appealing. If you need a little extra inspiration, step over to Garden for the Environment (7th Ave. and Lawton) and see how lovely and varied the late summer garden can be in San Francisco. If you come on a Wednesday or Saturday, you are likely to find us working there, ready to answer all your questions about sustainable garden practices in a summer-dry climate. Happy gardening, and may many hummingbirds visit your salvias!