Plan Now for Fall Crocus & Colchichum

I was thrilled to see the first evidence of Crocus foliage pushing their way out of the frozen soil today. Crocus is the earliest bulb (corm, really) to flower in the Mary Snoddy garden, usually in February. At times they are frosted by ice or snow, which doesn’t seem to dampen their cheerful demeanor one bit.

As much as I enjoy these harbingers of spring, I prefer the Crocus that flower in October and November. You will notice that I did not say “Fall-flowering Crocus” or “Autumn Crocus.” There is a good reason why. There are two different flowers which bloom at the same time and look very similar to the unpracticed eye. One produces saffron threads, a culinary delight. The other can kill you if you eat any part of it. Seriously.

Fall-flowering Crocus, Crocus sativus, pronounced CROW-cuss suh-TAI-vuss, is also known as Saffron Crocus. It is grown for saffron spice, as noted above, but the orange-red stigmas are also used for dye. They will stain fingers and clothing. This plant sends up narrow, grass-like foliage before the flowers appear. Plants are small, usually reaching about six inches when they are in flower. C. sativus is cold-hardy in zones 5-8. They prefer a neutral to slightly alkaline soil in full sun. They are occasionally damaged by voles or rabbits.

Saffron Crocus

Saffron Threads

Autumn Crocus is Colchicum autumnale, pronounced COAL-chik-um aw-tum-NAH-lay. It is taller (eight to ten inches) and its blooms are larger than C. sativus. It appears as a naked bloom, with no foliage at the time of flowering. Weak foliage appears in spring. It is more cold-tolerant (zones 4-10) than C. sativus, will tolerate a wider range of pH, and will withstand a bit more shade. The large pink or purple flowers look fantastic when they appear above a short groundcover like dwarf mondo grass, which also helps support the weak stems. All parts of the plant are highly toxic to people and pets. Deer and rabbits will not touch them.

Colchicum

Leafless Autumn Crocus

Tiny C. sativus is planted 2-3 inches deep. Larger C. autumnale is planted 4-6 inches deep. Both these corms are small and flat, and look best when planted in groups or drifts. They will naturalize when planted in the lawn. Pollinators are attracted to the flowers.

Easy, Pretty Tatarian Aster

Asters adorn the fall garden with clouds of blue blooms that show to advantage against yellow goldenrod, orange pumpkins, and the warm shades of autumn leaves. The Asteraceae family was one of the largest until those pesky taxonomists got involved. With their penchant for genetic accuracy, they reclassified North American asters into Symphyotrichum, Eurybia, and a number of smaller classes. For an exhaustive (mind-numbing) discussion of Aster’s new family tree, consult the University of Waterloo’s research report by clicking HERE.

Today’s feature plant, Tatarian Aster, was formerly Aster tataricus and is now Crinitaria tatarica (pronounced krin-ih-TAIR-ee-ah tah-tair-IH-ka). Tatarian Aster is a perennial wildflower with soft lavender-blue, star-shaped flowers held in flat-topped groups. The flowers have 7-20 petals each, arranged around a yellow center. Bees, moths, and butterflies love them. They provide a nectar meal for migrating Monarch butterflies.

Tatarian Asters grow in zones 3-9, in any soil type and almost any pH, and require full sun exposure. Plants are resistant to heat and humidity. They may gain heights of up to six feet, but rarely need to be staked unless they are grown in very fertile soil with plentiful moisture. Unless you enjoy staking, take a Tough Love approach to growing this perennial. Plants grown in rich soils with plentiful moisture can spread aggressively.

The height of Tatarian Aster means it is a good back-of-the-border feature. It is especially pretty when grown along the sunny edges of woodlands, paired with Miscanthus, Muhlenbergia, or other grasses. Deadheading spent blooms will lead to a lengthy flowering season, from late summer all the way to freezing temperatures. In winter, cut the dead foliage back to ground level.

Fall for Mexican Salvia

Members of the Salvia genus are beautiful and easily grown. Salvia leucantha, Mexican Salvia or Mexican Bush Sage, makes a great back-of-the-border plant, where its purple or purple/white bicolor flowers rise above shorter plants. They are a favorite of pollinators and bloom in the fall when other nectar producers are winding down. Mexican Salvia is tolerant of most soils (prefers neutral pH) and will withstand heat and drought. Early flowers will be all purple; later flowers will have purple calyces and white corollas. A pink form is available but I have not found it in local nurseries. Foliage has a gray tint. Flowering extends for weeks.

Salvia leucantha, pronounced SAL-vee-ah lew-KAN-thuh, is listed as an annual in Zones 6 and colder. An especially harsh winter may kill those in zones 7 or 8. Established plants have overwintered several years in the Mary Snoddy garden.

Plants may tower to six feet. ‘Santa Barbara’ cultivar is a dwarf, reaching only three feet. The taller forms may split or flop, so I recommend pruning them back by one-third around the first of July. Flowering may be delayed by a week or two but pruned plants will be shorter and bushier, which means more flowers and less staking (double win!). Shorter plants do well in containers. In the border, Mexican Salvia pairs well with yellow Lantanas or Black-Eyed Susans. Like other square-stemmed plants, it is easy to root from cuttings. Plant in full sun to mostly sun. 

Don’t confuse leucantha with Leucanthemum, Shasta Daisy. Also note that this is not an edible plant, despite the Sage moniker. Deer and rabbits pass this one by, which pollinators flock to it.

Nerine, an Autumn Alternative

If you are looking for fall flowers that are not chrysanthemums or pansies, look no further than Nerine, an autumn beauty. Clusters of tubular blooms top long, sturdy stems. Strap-like foliage resembles its cousins, Amaryllis and Crinum. Like those two, Nerine are not bothered by voles, deer, or rabbits. Nerine flowers usually have a little bit of ruffle along the petal edges. The flowers are fragrant.

Nerine bulbs (common name “Guernsey Lily” or “Autumn Amaryllis”) are native to South Africa and are marketed as cold hardy in zones 8-10, but have survived under a pine needle mulch in my zone 7b garden for a decade. Flowers are available in pink, white, and rose. They make a long-lasting cut flower.  They will grow in full sun or partial shade. Nerine make excellent container plants as well. They bloom best when slightly root-bound, so don’t be in a hurry to move them to a larger container or to divide those grown directly in the ground until they become congested and stop flowering freely.

Bulbs are planted in spring, when dormant. Nerine are different from many other bulbs in that they want the topmost portion of the bulb to be above ground. This is called “planting to the shoulders.” If planted too deep, you will have nice foliage but few blooms. I am especially fond of any bulb that does NOT need me to dig a hole halfway to the core of the earth. Some bulbs insist on deep planting. This is a challenge if your garden consists of rocks and red clay.

Nerine plants like heat, and don’t emerge until night temperatures have warmed. They do not like to be moved; newly planted bulbs may sulk for a season. It is worth the wait. They are drought tolerant, but will bloom much better if given some additional water whenever leaves are visible. Do not water while they are dormant (winter to early spring).

I find that the bold foliage of Nerine, Crinum and Amaryllis poses a challenge in beds. These do not seem to pair well with other bulbs or perennials. One option is to give them each their own section of the garden. I have taken a different tactic this year, and combined all three in a single planting. The foliage is so similar that I cannot tell which is which. If all goes according to plan, the Amaryllis will put on a spring show, Crinum will take its place in summer, and Nerine will finish out the year.

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Goldenrod good; Ragweed bad

This time of the year is bittersweet.  Sadly, the lovely yellow goldenrods (Solidago) that decorated flower beds and roadsides have been cut down by frosts and freezes. On the other hand, those same freezes knocked out the ragweed that makes me sneeze hard enough to knock the earth off its axis.

Because these two bloom at the same time, goldenrod takes the rap for allergy-sufferers’ misery. The true culprit is ragweed. Goldenrod is pollinated by bees. Its pollen is heavy. Ragweed pollen is airborne and easily inhaled. A single ragweed plant can produce over a billion grains of pollen - lots of sneezes!. There are exceptions, but usually a plant that is bee-pollinated (as opposed to air pollinated) does not have pollen that floats on every breeze, spreading misery to sensitive sinuses.  Ragweed blooms look similar to goldenrod, but they remain green and never change to gold. Gardeners can learn to distinguish between the two because ragweed leaves and branching structure differ from goldenrod.

Goldenrod is easily grown and perennial to zone 4. The roadside ditch varieties have given way to modern cultivars that are shorter, bushier and longer-blooming. These improved introductions spread less aggressively than their wild cousins, but they still colonize the surrounding soil with a fibrous web of rhizomes. Don’t plant them in locations where they can choke out weaker plants.

Goldenrods prefer full sun but will accept some shade. Once established, they are quite drought tolerant. Plants range from two feet to six feet in height, depending upon the variety. They are not picky about soil, and even seem to prefer heavy, acidic clay. The golden color combines particularly well with blue, so an easy combination includes asters, which bloom at the same time of the year. The taller variety looks good with purple Ironweed (Vernonia) and Mexican Bush Sage (Salvia leucantha).

‘Fireworks’ was introduced by the NC Botanical Garden and is widely available. It is on the taller end of the spectrum, reaching four feet or more. ‘Peter Pan’ and ‘Little Lemon’ are petite, reaching 18-24 inches.

Bonus points: Deer leave them alone.

Goldenrod blooming in the Mary Snoddy garden