Photo Credit: Mike White

Bulbs and Corms and Tubers – Oh My!

Bulbs, corms, tubers, and rhizomes are buried treasures that burst open in the Spring displaying floriferous bouquets of colour to welcome the season. Crocuses celebrate the melting snow, trumpeting daffodils hail the sunshine, and tulips cheerfully rejoice the arrival of warmer days. No doubt you’ve received your favourite bulb catalogue in the mail by now and are gleefully perusing through the pages, checking off your favourites. Let us help you with your choices!


Tulips, Daffodils and Lilies are a rounded modified stem with fleshy layers storing nutrients for the impending growth season. The bulb is shaped to a point similar to a tear drop and wrapped in a papery tunic (except for Lilies) with a basal root plate that anchors the plant snugly in their home.

Pollinator magnets:

  • Snowdrops (Galanthus sp.) are one of the earliest blooming bulbs known to flower before the vernal equinox, poking their little heads up above the melting snow; they are a honeybee favourite!
  • Striking vivid blue Iris reticulata heads follow close behind; another honeybee favourite!
  • Gigantic Allium balls serve as nectar lollipops; a favourite of most pollinators.


Gladioli and Crocuses have a round modified stem that usually looks like a little mini-pumpkin which stores food; corms do not develop layers of growth rings like bulbs do. The towering spires of Gladioli are available in a myriad of colours but are not hardy – they can be lifted and stored indoors for the winter. Hummingbirds are attracted to the vertical buffet of flowers. Colourful heads of Crocuses will burst through the soil in late March to early April and provide many pollinators, especially honeybees and bumble bees, with an ample load of life-sustaining pollen and nectar.


Tubers like Begonia, Cyclamen, and Potato, have a modified stem with several growth points called “eyes” without a tunic or basal plate. The nodes do not bear roots like rhizomes do. Tip: planting them on their side takes away the guess-work as to which is the top of the tuber!


Canna, Lily of the Valley, and Bearded Iris are horizontal stems of modified storage organs from which vertical above-ground growth takes place similar to ginger root. Nodes do bear adventitious roots. Perennial bouquets of Iris blooms are capable of producing a kaleidoscope of colour in early summer; they require lots of garden real estate as they multiply by producing more rhizomes so be sure to divide them every few years.


Check off your favourites in the bulb catalogue today and plant your little gifts before the ground freezes. The delicate treasures that cannot survive the toils of winter such as Cannas, Dahlias and Gladioli can be stored indoors until the ground is warm enough for planting. Alternatively, in early Spring you can get a head start by planting them indoors in pots and placing them in a sunny window allowing them time to establish a root system and peak their heads up through the soil in their search for Spring! Happy shopping!


Have questions about planning your spring garden? Email us at horticulture@cambridgebutterfly.com. Enjoy!