Yard And Garden: Removing Mulch For Spring Flower Preparation

Feb 25, 2016

By Richard Jauron

Extension Horticulturist

It might not quite feel like it yet, but spring is just around the corner in Iowa. With it comes preparation for spring planting and flowers. When is the right time to remove mulch and soil put in place to protect flowers during harsh winter conditions?

The timing can be tricky but Iowa State University Extension and Outreach horticulturists can help navigate challenges. To have additional questions answered, contact the ISU Hortline at 515-294-3108 or hortline@iastate.edu.

When should I remove the mulch on my strawberry bed?

To reduce the chances of crop damage from a late frost or freeze, leave the mulch on as long as possible. Removing the mulch in March may encourage the plants to bloom before the danger of frost is past. Temperatures of 32 degrees Fahrenheit or lower may severely damage or destroy open flowers. Since the first flowers produce the largest berries, a late spring frost or freeze can drastically reduce yields.

To determine when to remove the mulch, periodically examine the strawberry plants in spring. Remove the mulch from the strawberry planting when approximately 25 percent of the plants are producing new growth. New growth will be white or yellow in color. (If possible, the winter mulch on strawberries should remain until mid-April in central Iowa. The average date of the last 32 F temperature in spring normally occurs in late April in central Iowa.) When removing the mulch, rake the material to the aisles between rows. If there is a threat of a frost or freeze later in spring during bloom, lightly rake the mulch over the strawberry plants.

I covered the base of my hybrid tea roses with soil last fall. When should I remove the soil?

Remove the soil in late March or early April in southern Iowa, mid-April in northern portions of the state. A frost or freeze in early spring shouldn’t harm the roses.

After removing the soil, prune out any dead wood. Live wood is green and possesses plump, healthy buds. Dead wood is light to dark brown in color. When pruning, make the cuts about 1 inch below the dead, brown-colored sections. Remove the entire cane if there is no sign of life.

I covered a newly planted perennial bed with mulch in the fall. When should I remove the mulch?

Remove the mulch in late March/early April in southern Iowa, early to mid-April in northern portions of the state. Removing the mulch earlier in the year may encourage premature growth which could be damaged or destroyed by a late hard freeze.

Source: iastate.edu

Video: Spring 2026 weather outlook for Wisconsin; What an early-arriving El Niño could mean

Northeast Wisconsin is a small corner of the world, but our weather is still affected by what happens across the globe.

That includes in the equatorial Pacific, where changes between El Niño and La Niña play a role in the weather here -- and boy, have there been some abrupt changes as of late.

El Niño and La Niña are the two phases of what is collectively known as the El Niño Southern Oscillation, or ENSO for short. These are the swings back and forth from unusually warm to unusually cold sea surface temperatures in the Pacific Ocean along the equator.

Since this past September, we have been in a weak La Niña, which means water temperatures near the Eastern Pacific equator have been cooler than usual. That's where we're at right now.

Even last fall, the long-term outlook suggested a return to neutral conditions by spring and potentially El Niño conditions by summer.

But there are some signs this may be happening faster than usual, which could accelerate the onset of El Niño.

Over the last few weeks, unusually strong bursts of westerly winds farther west in the Pacific -- where sea surface temperatures are warmer than average -- have been observed. There is a chance that this could accelerate the warming of those eastern Pacific waters and potentially push us into El Niño sooner than usual.

If we do enter El Nino by spring -- which we'll define as the period of March, April and May -- there are some long-term correlations with our weather here in Northeast Wisconsin.

Looking at a map of anomalously warm weather, most of the upper Great Lakes doesn't show a strong correlation, but in general, the northern tiers of the United States do tend to lean to that direction.

The stronger correlation is with precipitation. El Niño conditions in spring have historically come with a higher risk of very dry weather over that time frame, so this will definitely be a transition we'll have to watch closely as we move out of winter.