Summer Blooming Bulbs
By Sandy Metzger, Sonoma County Master Gardener
Bulbs are not limited to the spring-flowering, ubiquitous daffodils, tulips, and hyacinths. In fact, summer bloomers are some of the most beautiful and versatile of all, as they can be useful in cottage gardens, herbaceous borders, naturalistic settings and meadows, rock gardens, containers, and as cut flowers. March is the time to shop for them in your local garden centers or order them on-line.
Some are true bulbs and hardy, such as lilies and alliums, and can be planted in the fall when dormant, but many are considered more tender and are better planted when the soil warms to at least 50°. In colder regions of the country, tender summer–flowering bulbs need to be “lifted”, stored over winter, and replanted in the spring. Why bother? Here in Sonoma County, as long as the bulbs are established and have adequate drainage, most can remain in the ground year after year.
Most bulbs become “permanent”, much like perennials. Their spent blooms need to be deadheaded and foliage cut back once it has browned off. Also, every couple of years, it’s a good idea to divide the bulbs and plant out their bulblets or cormlets. Most bulbs thrive in rich, well-drained soil and will naturalize slowly over the years.
When asked about summer-flowering bulbs, people will immediately mention cannas, dahlias, gladioli, and lilies. These are, in fact, some of the most common, most popular, and have been hybridized to offer the most varieties. Each of the species is so large and varied that specialized books have been written about them. So, I’m not going to address these here except to say they are all beautiful; none is invasive; some are fragrant; they come in every size, color, shape and are readily available everywhere.
One of my favorites is Liatris, or Gay Feather. Because its foliage is grass-like, I interplant clusters of Liatris with ornamental grasses. Then in July and August when much of the garden is dry and ratty looking, up pop these 2-1/2 foot high spikes with purple, pink or white bottle brush-like flowers, appearing almost as if the ornamental grasses were blooming. The butterfly-loving Liatris bloom for almost two months and make excellent cut flowers. You can find them in stores right now, usually sold by color in bags of 15-30.
Here’s a bulb that people seem to either love or hate: Crososmia. It’s another tall, spiky plant generally in brilliant red (‘Lucifer’) or orange. It can grow to 3 feet and makes a good cut flower. The reason people do not care for it, I believe, is because it can “naturalize” very quickly. If you reduce its water, rapid spreading won’t be an issue. Otherwise, it adds bright vertical touches of color to the garden; grown in masses, it’s a knock-out!
There are three bulbs I always mentally lump together, Freesia, Ixia, and Sparaxis, not because I plant them together, but because they’re all sold in bags of mixed, rather gaudy colors. If you’re persnickety about color-coordinating sections of your garden, these are not for you! But if you like an entire raging rainbow, plant any or all of these for their red, pink, orange, crimson, mauve, purple, and cream flowers. The Sparaxis grow to only about 12”, but the Freesia can get as high as 18” and the Ixia to almost 30”; the latter two grow on slim wiry stems and may need support. Because the Ixia stems look almost like grass or a weed when they first appear, it’s easy to inadvertently pull them out. Don’t be tempted!
For gardeners with clay soil, feel free to plant Mirabilis, or Four O’Clock, which likes a warm sunny site and doesn’t open until mid-afternoon or later. It has red, yellow, or white trumpet-shaped flowers on bushy foliage; it blooms July to the first frost, and though it readily seeds around, the volunteers are fairly easy to pull out when young. Keep your eye on it!
A bulb that does not appreciate clay is the June -August blooming Ranunculus. If you do have clay, amend it thoroughly with compost and create mounds before planting the claw-like tubers (down). The foliage is bright green and fern-like, and the semi-double to double flowers range in color from yellow, orange, and red to pink, cream, and white. Ranunculus makes superb cut flowers.
Following are some names of other summer-flowering bulbs that do well in Sonoma County: Agapanthus, Alstroemeria, Amaryllis belladonna, Begonia tuberosa, Chasmanthe aethiopica, Dierama pulcherrima, Eucomis comosa, Galtonia, Incarvillea, Nerine bowdenii, Polyanthus tuberosa, Schizostylis coccinea, Tigridia pavonia, and Tritonia. There are many, many more.
Try local nurseries and garden centers before ordering on-line; many have expanded their offerings due to interest in the less common bulbs. Otherwise, you’ll have to take time to search for particular bulbs as not all of the on-line companies sell all of the bulbs.