(Editor's Note: This article was originally published on March 21, 2008. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
Favorites among spring bulbs
Sunny spring days find many homeowners roaming their yards looking for signs of crocus. Its cuplike blossoms in shades of yellow, white or purple are a great antidote to winter blahs. When daffodil leaves poke up from the soil and snowdrops bloom, crocus are coming to life. Diminutive striped foliage appears and bright buds follow about four weeks later. Crocuses bloom before most daffodils and even beat the Forsythia bush to first flowering. After the petals fall, crocus' narrow foliage will lengthen, grow for several weeks to renew the bulb, and then disappear until next year.
Everyone knows the Dutch crocus
The most widely sold and used crocus is the Dutch crocus, Crocus vernus. They have been bred for larger flowers and a range of colors. You can buy individual colors or mixed color bags. Dutch crocus can fill a bare winter flowerbed or be sprinkled across a lawn. Each bulb produces one, or more, two-inch flowers on about four inches of stem. Dutch crocus is a cheerful addition to almost any yard.
Be the first one on your block with Tommies
The hardest part of planting these Tommies was finding thirty holes between the maple roots!If you already have Dutch crocus, you may be ready for something new. This autumn, look beyond the big box store fall bulb display. Visit a quality nursery or go online and look for a species crocus. Crocus Tommasinianus is one of the more common of the species types. Also called early crocus, or more affectionately, Tommies, they can be found in shades of purple and white. Tommies are both smaller in overall proportions and earlier to appear than Dutch crocus. Dutch crocus join the party just a bit later; the yellow Dutch flowering period may overlap with Tommies. I got my bag of thirty 'Whitewell Purple' tommies several years ago, at a big nursery with an extensive selection of bulbs. An online search for "Crocus tommasinianus" or a look at Dave's Garden's Garden Watchdog should lead you to a number of companies selling these bulbs.
Both are easy for early bloom
Both crocuses lend themselves to a variety of situations in zone 3 through 8 gardens with full or part sun. Avoid a moist spot; they'd rather be dry during the summer. They're often used in flowerbeds to fill the void between dormant perennials. They can also be planted into your lawn, as long as you can avoid mowing the area until the foliage has matured in middle to late spring. Plant crocus bulbs pointed end up in the fall. Dutch crocus go four inches deep, while the smaller Tommies should just go to two or three inches. A bit of bulb fertilizer gives a boost, but is strictly optional for these tough little bulbs.
Dutch crocus should be happy in one place for years with no attention. Tommies are said to self-sow. That means they could spread beyond your original planting. In my garden they've stayed put for four years, now giving me about four flowers for each of the bulbs I planted.
Pick the right crocus for the spot, the right spot for the crocus.
Dutch crocus are great in a bed of periwinkle at the curb
Use Dutch for viewing from afar and tuck the Tommies in where you'll enjoy them up close. The two are somewhat interchangeable but the bigger Dutch are a better choice for impressing the neighbors. They're just more visible. Their height advantage makes them the right crocus to use in a low groundcover like common periwinkle (Vinca minor.) But remember, either crocus will be hidden from view by anything taller than about six inches. Smaller-scaled Tommies are charming on bare or shallowly mulched ground, where you'll be sure to notice them. Crocuses even thrive between tree roots. Actively growing only while rain and soil fertility are abundant allows them to reappear and mutiply year after year.
The similar size and complimentary color of Iris danfordiae make it a suitable companion to Crocus tommasinianus. Most daffodils are not yet in bloom, but crocus could get lost in their foliage. Only the earliest and smallest daffodils can be mixed into a crocus planting.
But wait, there's more
Crocus vernus and Crocus tommasinianus are just an introduction to the crocus clan. While checking my information, I learned that there are 80 crocus species, and other plants with "crocus" in their common name. With this array, you can enjoy crocus-like flowers almost non-stop from fall through spring. I hope I've told you what you need to know to begin, or go further, with crocus. Now I need to go decide what I'll be adding this fall!
References- Both of these books gave extensive information on their subjects, along with gorgeous color photos. I especially liked the Christopher Lloyd book for its plants-only Latin name index which allowed me to quickly check my spelling of "tommasinianus."
Ellis, Barbara W. Taylor's Guide to Bulbs. Houghten Mifflin Co., New York, 2001.
Lloyd, Christopher. Christopher Lloyd's Garden Flowers. Tmber Press, Portland, 2000.