Our redbud is beginning to leaf out, but very few of the flower buds have opened

Asked May 18, 2019, 1:57 PM EDT

We planted this tree about three years ago. Purchased it via the Mpls lottery, Tree Trust collaboration. I'm a gardener, so have paid attention to watering and planted it according to U of M extension consultant recommendations. Do you have any ideas of a) what is causing this and b) if there are any remedies? Thank you, Donna McNamara

Hennepin County Minnesota

1 Response

Thank you for the question. Redbud, Cercis canadensis, isn't reliably hardy above zone 5, unless you purchased the Minnesota hardy strain of redbud developed by the Landscape Arboretum which is hardy to zone 4.

If you know you have the hardy strain, consider other factors for few blooms:
  1. Immaturity. It might take a few more years of growth before it puts on a full display.
  2. Lack of sunlight. Redbud are usually do best in full sun or at least only part shade.
  3. Too much fertilizer. Excess fertilizer can contribute to wonderful green growth at the expense of flowers.
  4. Blooms got pruned off. Redbud set blooms at the end of the summer for next year. Pruning is recommended right after the plant blooms.
  5. Cold weather. We had unusually cold weather last this spring and very cold winter. The majority of blooms may have frozen.

There is nothing to be done, assuming the tree is healthy, except take good care of it this season and hope for more blooms next year.

Thank you for contacting Extension.