In the first issue of PITH + VIGOR, Joanne Neale shared four great planting combos for fall-blooming bulbs - but some of the combos hit the cutting room floor. They were pretty great - but we just didn't have the space to print them all, so here are the other thre, plus a recommendation for serious bulb-o-files - for even more inspiration.
Pairings for Fall- Blooming True Crocus (USDA Zone 4-6)
Crocus speciosus + Sedum cauticola
Crocus speciosus is indeed a relative of the common spring crocus (you know, the one that looks great until the squirrels eat the flowers), with both flowers and foliage similar in appearance. Most autumn crocuses come from Mediterranean climates and are only hardy in Zones 7–9, but those from the European continent can survive in Zone 5.
The most widely available is Crocus speciosus (very large violet flowers, there is also a white form). Also Zone 5-hardy are c. nudiflorus (very large violet, tolerates moist soil and naturalizes in thin grass), c. kotchyanus (purple with a gold throat) and the pale lilac c. pulchellus (October bloom with spring foliage; a white-flowered form is ‘Michael Hoog’).
If you garden in Zone 6, try c. goulimyi (lilac-blue, fragrant) and c. laevigatus 'Fontenayi' (white brushed with lilac, early winter). Two pure white-flowered varieties are c. hadriaticus "Annabelle” and c. niveus. Also hardy in Zone 6 is the saffron crocus, c. sativus (purple-striped blooms) and C. cartwrightianus whose stamens can also be used as saffron. Hardy to Zone 4 is c. banaticus (the so-called "iris-flowered crocus") which tolerates damp soils and has very broad leaves that appear in spring rather than fall (lilac to purple).
Since most crocus flowers only open in the sun (exceptions being c. banaticus and c. pulchellus), select a site with good sun exposure. Plant bulbs in late August or early September about 3 inches deep in humus-rich soil that is well-drained.
By planting among low groundcovers such as Sedum cauticola, you will eliminate the damage caused by mud splashing onto the blossoms from fall rains. They are also a fantastic surprise if planted in lawns and allowed to naturalize. Be sure not to mow the foliage, which must persist until dieback to allow the bulb to complete its life cycle; later-blooming varieties such as c. goulimyi, c. laevigatus 'Fontenayi' and c. niveus are best for this use.
Pairings for Colchicum (USDA Zone 4/5-9)
Athyrium 'Ghost' + Colchicum + Anemone japonica
Commonly called the "autumn crocus,” this is actually not a crocus at all as its flowers have six stamens, while the true crocus' has three. Botanically, the crocus belongs to the Iris family (Iridaceae), while colchicum is a member of the lily family (Liliaceae). Another important difference is foliage. The true crocus' is fine and grassy, while colchicum's is more like hosta leaves but which tend to dieback badly in June (turning yellow and being prone to snails and slugs). Plant late-appearing perennials like Platycodon (balloon-flower) in front of them to camouflage.
Wonderful blooming companions for colchicum are tricyrtis (toad lily) and the fall-blooming Anemone japonica, as well as ferns such as Athyrium "Ghost".
Each corm produces four to six flowers ranging from 4-12 inches high. With the exception of the Zone 6 c. "Violet Queen,” all are hardy into Zone 5 (Zone 4 with protection). The first to bloom is colchicum autumnale (1–2 inch lilac-pink flowers). There is a double form, c. autumnale "Pleniflorum", a white form, "Album" and a double white, "Alboplenum". A bit later is the much larger-flowered colchicum speciosum (3 inch raspberry-tinged purple-pink), which also has a white cultivar, c. speciosum "Album". Other c. speciosum cultivars worth growing are "The Giant" (10–12 inch high rosy-lilac flowers with a white center) and "Waterlily" (6-8 inches pinkish-purple to mauve, and it looks like—what else—a water-lily).
Colchicum should be planted in late summer in any well-drained, moisture-retentive soil in sun to partial shade. It is important to plant as soon as possible after receiving your plants, and the shoulder of the corm—where it begins to broaden—should be set at soil level. All parts of colchicum are poisonous to critters that may be tempted to eat them.
Pairings for Allium thunbergii
Sharing the amaryllis family with sternbergia and lycoris is Allium thunbergii, an ornamental onion from Japan. The select cultivar “Ozawa” reaches a maximum height of 10 inches, perfect for a rock garden setting.
From September into October, 1-2 inch heads of bright violet flowers top the attractive, narrow, thread-like foliage. Its flowers are impervious to frost and snow.
In later fall the leaves will turn tawny orange, which is striking in a mass planting. I love it with Aster lateriflorus “Lady in Black” as a background. The dark foliage of the aster with its cloud of tiny white flowers is a perfect foil for the star-like blooms of the allium. Another good companion to add to this tableau is the October Daphne, Sedum sieboldii.
Suitable for full sun to partial shade, this allium is another low maintenance beauty, requiring only average welldrained soil. The bulbs will rot in damp conditions.
For True Bulbophiles: Two More Challenging Selections
A bit more tender, expensive, difficult to grow, or hard to find, these autumn bloomer bulbs are worth the challenge. Try planting in containers (and bringing them into a protected garage or basement) if they are beyond your zone.
RHODOPHIALA BIFIDA (Oxblood Lily - Comes in both Red and Pink )
Tall (15 inch) amaryllis relatives from Uruguay and Argentina, bloom in late summer-early fall on leafless stems; foliage appears after bloom. Prefer alkaline soils. Full sun (USDA Zone 7).
images: Proven Winners, IamNotUnique by CC plant delights, Tim Waters by CC, germana by cc, benjamin golub, Meneerke bloem by CC. pris.sears (CC by-NC-SA 2.0), Todd Boland With Permission, jacki-dee (CC by-NC-SA 2.0)
Most of these bulbs can be found at Odyssey Bulbs.