The squill have sprung forth, the crocus, daffodils and tulips are making their appearances too. Spring is here! Wahoo…
Squill
So when do we plant Summer flowering bulbs?
It can be confusing. We plant Spring flowering hardy bulbs like tulips, daffodils and allium in late Fall. In fact, we plant them until the ground freezes. Those hardy little things hang out in the soil until they’re ready to show themselves, which is now!
But what about those tender bulbs, the Summer flowering bulbs like dahlias, caladiums, elephant ears, tuberous begonias, gladiolus and cannas?
Gladiolus
Plan on planting them outdoors after the soil has warmed up to around 60 degrees. That’s roughly mid to late May. Our last “official” frost date for zone 4 is May 15th, however, with the Earth warming, this is changing. According to Dr. Mark Seeley, University of Minnesota professor emeritus and meteorologist, he says our last frost date is now in April! Read more here. (I would note that we had 8 inches of snow on April 12th, 2020). Just sayin’! The National Weather Service has a map of soil temperatures.
If you want a jump start, plant them indoors now:
- Choose clean containers with drainage holes. These could be those pots from the nursery where you bought last year’s plants from.
- Use a commercial potting soil mixed with a 50/50 split of peat moss and perlite. The goal is good drainage. Bulbs do not like to be wet.
- Place the bulbs in the soil mix based on the directions on the package. Various summer bulbs are planted at various depths.
- If you saved bulbs, plant them about two to three times as deep as their diameter. So, a one inch bulb would be planted two to three inches deep.
- Soak the soil, unless you wet it down before you planted. Information about whether to dampen the soil mix first will be on the package of soil.
- Make sure the water drains out and the bulbs never sit in water.
- Place in a warm, sunny window.
Note that our soil temperature is generally about 60 degrees when our nighttime air temperatures remain at or above 60 degrees for a couple of weeks. A soil thermometer is more precise! If you plant them when the soil is cooler, you won’t kill them but they won’t do much until their “feet” are warmed and the sun is shining. Suddenly The Garden Scoop is thinking of toes in warm fluffy dirt and full sun on the face! ????
In Fall, after those beautiful blooms have faded and the foliage is browned, you can dig those bulbs out of the ground. The Garden Scoop was a little late last year but these gladiolus bulbs are storing in the basement right now…
Gladiolus bulbs dug out in late October
Audra shares all the summer flowering bulbs and the edibles too on our YouTube channel. Click here.