We are entering into the summer months and spring blooming landscape plants are finishing up their floral displays for the season and you may be wondering what to do. Here are a few tips to keep spring bloomers healthy and coming back brillant every spring.
Spring bloomers like tulips, daffodils, hyacinth and iris grace us with bright and happy blooms for the early spring and summer months, but when they are done blooming what do we do? When the flowers are done we are left with the leaves and stalks. The remaining parts of the plant keep photosynthesizing, creating food and energy for the bulb, corm or rhizomes below. It is best to leave the leaves and other green parts standing until mid summer when they will turn brown and dieback on their own. To prevent energy going to seed production, cut off spent blooms once they are finished.
Spring shrubs come with their own set of maintenance routines and pruning at the wrong time can affect blooming next year. Forsythia are the first shrubs to send out their bright yellow flowers even before the leaves some years. Prune after it is done blooming to maintain its shape. Mockorange sends out its beautiful white flowers, that smell like orange blossoms, in late May, and pruning should be done immediately after blooming ends. Lilacs should also be deadheaded (only removing the spent flowers) after blooming has finished. New flower buds for next season start forming shortly after the current year's blooming has finished. Newly planted lilacs can take 1-2 years to bloom and do not require pruning for 2-3 years. There are many types of lilac shrubs, some of which will bloom multiple times a season and they come in a variety of colors.
Hydrangea though a summer-fall bloomer, does require thought when it comes to timing pruning. Hydrangea with a cone shaped flower, provide great winter interest and can be pruned in late winter or spring. Big leaf hydrangea (macrophylla), produce flower buds for the next season in late summer to early fall, and should be pruned after they finish blooming. Smooth hydrangeas, like Incrediball and Annabelle form flower buds on new growth and can be pruned to the ground in the spring after being established for a couple years.
If you didn’t time your pruning right your shrub may have less or no blooms the following year, but this will depend on the level of pruning that was done and what type of shrub you have. Plants are forgiving, and should be back to normal blooming the following year!
*When renewal pruning older established shrubs, remove up to ⅓ of the oldest, thickest stems or trunks down to the ground.
For more information visit https://extension.umn.edu/how/planting-and-growing-guides and for questions about this article or local assistance, please contact Clay County Extension Educator Jill Patrie at 218-299-7388 or by email at patri350@umn.edu.