When To Plant Petunias In Michigan

Mother’s Day greetings! In southeast Michigan, it is best to hold off on planting warm-weather annuals like geraniums, impatiens, and petunias until the middle of May. Otherwise, these delicate plants can suffer severe damage from a sudden cold spell, especially when they are young. Every Mother’s Day, the family participates in a tradition by giving a few hours to planting annuals. It all started with young people scrawling coupons in different crayola colors. They were constantly saved. It’s a present that keeps on giving all through the growing season.

The frigid weather had no effect as I sat in “The Big House” in Ann Arbor with 11,000 of the best and brightest fragile seedlings and 40.000 other family members. The frigid wind was repelled by our community’s pride in our young upstarts and the warmth of our emotions. The young trees are prepared for relocation. It didn’t start to snow until we hurried back to the car lot. As in a garden, timing is crucial in life.

Depending on the conditions, cold-tolerant annuals like pansies and violas can be planted safely from early to mid-April. Many people have thrived and survived this warm winter.

When choosing a time, take into account the location of the planting on your land. Annuals can be planted earlier in sunnier places than in cooler, shady areas. Take a look at your garden’s perennials. Some hosta still have asparagus-like shoots sticking out of the ground, while in other places, they are fully in bloom in a ring shape. Plant earlier and in the latter.

Avoid falling for the early appearance of sunny impatiens flats at large box stores. Although it’s alluring, those adorable, colorful babies spent their first years in a heated greenhouse. Keep in mind that annuals are simply tropical plants planted in the wrong area. The jolt of putting them on the brisk ground can be substantial. More hazardous are the torrential downpours that frequently hit Zones 6a to b in April and May. Being submerged in a pool of accumulated rainwater isn’t ideal for those younglings because they can’t swim yet.

In addition, early flats are frequently expensive. The best prices start when Michigan-grown flats start to arrive in May at Eastern Market (visit around 2:00 pm for the best deals). Plants that are planted nearby have a better chance of prospering. Wait until mid-June before planting newer non-native favorites like Angelonia and Cleome.

My personal favorite is Block’s Marketstand and Greenhouse, but every gardener has their own. Block’s does not open a second before the plants are good and ready. A recording that answers the phone at the greenhouse in mid-April informs the caller that “We will open around the end of April.” The wait is worthwhile. The flowers are in good health, there is a huge variety, and they are inexpensive.

It’s still advisable to “harden” off the plants, even if they are local. This process only takes a few days and requires putting the animals out during the day and bringing them home at dusk. At night, they can relax in the garage.

In Michigan, when should you begin planting flowers?

You need to pay very close attention to your local weather in the spring, as you may have already suspected. You must keep an eye on the latest frost date in particular.

In general, you are SAFE to plant your spring flowers outside in Michigan once there hasn’t been a frost for two weeks!

I put together this table with the typical frost dates for the most of Michigan’s major cities for your reference. If your city’s last and first frost dates are not given below, you can find them HERE.

Michigan Last & First Frost Dates

The last frost occasionally occurs much later. In Michigan, you can grow your spring flowers outside considerably sooner if the final frost occurs earlier sometimes.

You must monitor your local weather frequently, as I’ve already stated.

Bring indoors any potted spring flowers if you have any.
Cover any spring flowers that are already in the ground with burlap and pray that they survive.
If spring flowers are planted too late, they won’t blossom at all or just bloom briefly.

In Michigan, when is it too early to plant?

The spring of 2021 is two weeks earlier than average temperatures, which has some ramifications for Michigan gardening.

The arrival of spring! On March 20, 2021, the day and night lengths were equal at the spring equinox. Spring, though, is more than just a day on the calendar when it comes to the landscape. The yellow witch hazels bloom, followed by the crocus and the peony leaf poking through the earth, much like every other season. Every gardener is pleased about these changes and wondering if they can start their gardens now.

Keep in mind that the weather does not always warm up in the same way, and there are years when the start of warm weather is earlier than usual. We are lucky to have many years’ worth of meteorological data gathered, which may be used to make decisions in the garden by estimating the approximate windows when certain events (such crabgrass germination, pest emergence, etc.) will happen.

How will the spring of 2021 differ from the historical average? Growing degree days (GDD) are ahead of plan as of April 1 in most of the state, particularly in southern Michigan (Figure 1). A figure known as GDD is determined by calculating the heat that has collected over time at a low temperature, such as 50 degrees Fahrenheit. These heat maps of Michigan show GDD values in the range of 0 and 115 GDD. The more heat that has accumulated in the area, the warmer the color.

With the exception of a few shoreline locations, the spring of 2021 is phenologically more than two weeks ahead of typical. How does this affect you? Could we plant now? Seasoned Michiganders are aware that spring weather frequently detours into snow and frost, despite the warmer than usual spring possibly inspiring spring fever to get outside in the garden. Gardeners in Michigan could start planting certain cool-season annuals now, such snapdragons and pansies, but they should be careful not to get too far ahead of themselves. Although the ideal window for crabgrass preemergent is earlier than usual due to the early spring, it is still too early to plant your tomato seedlings.

Oak pruning

Oaks should not be pruned between the middle of April and the middle of July, according to Michigan State University Extension, in order to stop the development of oak wilt, a disease that is well-established in Michigan and causes the quick loss of trees. Should the oak pruning window close sooner given that the landscape is developing around two weeks ahead of schedule? Deb Mccullough, an associate professor of forest entomology at MSU, claims that there is a two-week window around April 15 to account for early warm weather. However, she notes that “there are always microclimatic distinctions,” such as the fact that a south-facing face warms up more quickly than an east or north aspect or that the top of a tree warms up more quickly than the lower canopy.

If oak pruning is required, pick a certified arborist who is familiar with the disease and pruning guidelines. They are qualified to assess the circumstances in a specific location. The International Society of Arboriculture can help you locate a licensed arborist.

Crabgrass preemergent timing

A summer annual weed called crabgrass sprouts from seed every year. Applying preemergent herbicides that stop germination prevents crabgrass growth. The best time to use these is in the spring, when the soil temperature is between 50 and 55 °F. This window will change every year.

You can buy a soil thermometer to check the soil temperature on your lawn, or you can use the GDD Tracker instead. To find out when to apply effectively in your region, enter your zip code. Note that there is a lengthy application window. The ideal period to apply crabgrass preemergent is between 200 and 500 GDD base 32 F, as shown by the zip code for Grand Rapids, Michigan, which indicates that we are at 388 GDD base 32 F.

Frost-free dates

Phenology can provide information on how plants are growing and how the soil is warming, but it cannot provide future predictions. Plants that are susceptible to cold, such as tomatoes, peppers, and zinnias, can die in freezing or very freezing conditions. Frost-free dates inform us of the days of the year when we are, statistically, least likely to experience cold-sensitive clothing-killing temperatures. Don’t let the early spring weather trick you into planting frost-sensitive plants, such as flowers or vegetables, before the frost-free date in your region. Frost can be tolerated by cool-season flowers like pansies, snapdragons, ranunculus, and pericallis, but gardeners should be cautious of cold conditions.

Consider planting cool-season veggies in your garden whenever the soil reaches a temperature of 50 degrees Fahrenheit. Wait until the frost-free dates have passed and the soil temperature is above 70 F before planting warm-season veggies.

What can I currently plant in Michigan?

Cool season veggies, which demand cooler conditions for seed germination and plant growth, are a great way to kick off your gardening season sooner. Some plants can be sown in the same row.

Gardeners with a little common sense understand that they don’t need to wait for those sunny, 70 degree days to begin planting in the vegetable garden. Some “cool veggies” favor the cooler springtime temperatures for seed germination and plant development. In order to fully benefit and lengthen your gardening season, you should start growing what are known as “cool season veggies” as soon as the ground can be worked in late March to April, depending on where you are in Michigan. Use this clever technique to benefit from fresh greens, root crops, and cole crops sooner.

A variety of cool-season veggies can be sown as soon as the soil reaches 50 degrees. Cooler soil temperatures are preferred by and occasionally necessary for the germination of cool season plants. Onions, parsnips, mustard greens, beets, peas, carrots, turnips, cabbage, spinach, kohlrabi, cauliflower, radish, celery, Swiss chard, kale, and collards are a few of them. Using a soil probe or a kitchen thermometer that monitors both hot and cold temperatures, determine the soil’s temperature.

It’s crucial to get your soil ready for planting. Seeds will decay in soils that have been saturated with water before they are planted. Before planting, make sure the soil is not too wet. Additionally, cultivating or otherwise disturbing too-wet soil will ruin its structure and harm the microbial population that supports good soil. To deposit seeds that have not been regularly cultivated, soils should be lightly tilled or broken up.

Making plans for companion planting and different food garden strata at this time is also a terrific idea. Plant beets and radishes with your lettuce. While the radishes and beets will push down into the earth, the shallow-rooted lettuce will grow close to the soil’s surface. These root crops will naturally aerate and expand the water and air spaces in the soil. The essential soil bacteria will have a place to reside thanks to plant roots. For the same result, scatter onion sets throughout your greens. You can reseed another crop while allowing the root crop to finish maturing if your greens die back or bolt.

Plant peas among a ground cover of greens to take advantage of their vining nature. Use a trellis to support your peas vertically, and lettuce or spinach to protect weed seeds by shading and cooling the pea roots. Even pea seeds can be sown in a spring porch pot with pansies or snapdragons that tolerate chilly weather.

Think about adding some perennial vegetables like rhubarb and asparagus. Although they will require more space and a permanent site, these crops will continue to produce fresh asparagus spears and rhubarb stalks if they are established and well-managed. Select a spot with good drainage for each, then amend the soil with organic materials like compost. It will continue to be a wise practice to build healthy soils to add composted material annually around the base of the plants after they are established.

Season extenders, like low tunnels or cold frames, can also be incorporated by clever gardeners to help warm spring soils more quickly and aid in the germination of cool-season crops. As the sun rises higher in our spring sky, its inherent energy causes these covered beds to warm up. These season prolongers can significantly increase your productivity while also offering protection from late-season frosts.

Reseeding a mid- to late-summer “cool vegetable crop for fall harvest as well” is something that astute gardeners can do. Plant greens, for instance, even in late August for harvest in the fall.

Is it too soon to plant petunias in April?

Stunning petunias are among the most well-liked flowers due to their amazing blossoms and protracted blossoming time. By summertime, they become lanky like most annuals do, so you should cut the shoots back to about half their original length. See how to grow petunias and care for them to keep them in bloom.

About Petunias

In most regions, petunias are cultivated as annuals, however in zones 9 to 11, they can be grown as sensitive perennials. The blooms bloom from spring till frost and come in a variety of hues and patterns.

These vibrant annuals are frequently used in borders, pots, hanging baskets, and even as temporary groundcover because of how well they can brighten up a front yard. Some even have a faint scent. Their spread along the ground can be anywhere between 18 inches and 4 feet, and their height can range from 6 inches to 18 inches.

Types of Petunias

Petunias are categorized into several categories, primarily according to flower size:

The most resilient and productive petunias are multiflora varieties. They are perfect for summer bedding or in a mixed border because they have smaller but more numerous flowers (because they are more tolerant to wet weather).
Grandiflora petunias grow well in hanging baskets or pots since they have very enormous flowers (because they are more susceptible to rain damage). Due of their susceptibility to rot during humid, hot summers, these huge petunias frequently do not thrive as well in the south.
Between the grandiflora and the multiflora groupings, floribundas constitute a middle ground. Similar to multiflora types, they are free-flowering and have medium-sized blooms.
Compared to other petunias on the market, milliflora petunias are significantly smaller. Despite just being 1 to 1 1/2 inches across, the flowers are abundant and bloom the entire season.
Low-growing, spreading or trailing petunias can spread as much as three to four feet. The flowers develop throughout the whole length of each stem, forming a stunning, vibrant groundcover. They can be utilized in hanging baskets or window boxes.

Petunias require full sun to avoid becoming spindly. In the shadow, they don’t typically flower well.

Particularly in containers, the soil should be able to drain effectively and not become too damp. In order to encourage the best growth, it should also be relatively fertile. Before planting, amend poor soil with finished compost.