Spring in Michigan is always a temperamental time. One day it’s sunny and 70, and the next day it’s snowing. Drop the words “frost free date” anywhere in a Google search and you can get the average date predicting when it’s safe to plant.  The problem with averages is that they come from data on both sides of the average and using this date could leave you frost-burnt as frequently as half the years.

Here at Christensen’s, the full moon in May, or the ‘Flower Moon’ is something we always keep top of mind along with the average frost-free dates. Each spring, we take out our calendars, look for this ever-changing date, and wait patiently. The reason being is that many in our nursery believe that until we are past this milestone, we are still at risk of a frost. Sometimes we get lucky, and this turning point is early, and in other years- like this one, it is late.

The full moon in May was named, as other monthly moons were, by Native American tribes. In regions that were covered in carpets of flowers, the commonly used name of Flower Moon was coined. Other Native American cultures used different names based on what was occurring around them at that time such as Corn Planting moon or Blossom moon. This full moon paired with a clear night has long been believed to bring bitterly cold and unseasonable weather with the threat of hard frosts. The best example of this was the 2020 Flower Moon which brought a cold snap that extended for several days.

Depending on your source, some people believe the Flower Moon is a strong indicator, while others believe it is a long-held myth.  While researching we contacted our favorite local source for all things horticulture, Michigan State University, and asked if they knew of any scientific source that could prove or disprove the moon’s effect on frost. One response was that there isn’t much research on the connection.  Another thought is that it is likely a timing thing – which leads to conclusions that may or may not be able to be proven.

Whether you believe in the Flower Moon or not, we can all agree that, for us in the horticulture industry, a sudden burst of cold weather can be very bad news.  It is dangerous to fresh foliage, buds, and flowering trees.

As you probably know, plants spend the winter in a sleep called dormancy. This dormant period naturally hardens off your shrubs and perennials to withstand the harsh winter temperatures. However, once your plants start to emerge in the spring, we become concerned about colder temps. There are 3 types of freezes issued by the National Weather Service- Frost, freeze, and hard freeze. A frost- sometimes called ‘Killing Frost’ is just frozen dew. Water on the ground, and on the leaves of plants become frozen when temps fall into mid-30s, and winds are calm. A freeze is when temps are at 32 degrees and conditions such as wind prevent the formation of frost. Lastly, a hard freeze is the most serious and occurs when temps drop below 28 degrees for an extended period. It is worth noting that the length of freeze overnight matters. A 1-hour freeze before sunrise is not as worrying as an hours long freeze in the middle of the night. All types of freeze warnings must be recognized, and a plan of action set in place.

The Flower Moon this year is late and will not occur until May 23^rd. If you pair the Flower Moon with the averages that range from May 23^rd to May 27^th, depending on where you are, you will want to watch low temperatures and come up with a plan to combat the frost. Houseplants or potted material can easily be moved inside and out of the cold. In a nursery setting, or in your customers’ yards, here are some tips to mitigate some potential frost damage. At the nursery, we do two main things to battle against frost. Our first method is the continuous running of our irrigation. This frost protection program starts in the wee hours of the morning and runs every 45 minutes for 5-minute spurts throughout the entire nursery. This protects plants by using the heat of the water to continuously warm the plants. Our second mode of action is to use frost protection blankets. These blankets are typically lightweight but effective and do a nice job of keeping the frost from hitting the newly flushed leaves and buds. This method is less practical when talking about protecting an entire nursery, but a very effective plan for flower beds, or to cover smaller groups of our flushed perennials, and Roses. Tucking our plants in before a cold night gives us the peace of mind that they are safe and sound. Some other methods used across the industry are frost fans, under tree sprinklers, keeping grass short to absorb heat, frost protection sprays, and even the use of helicopters to increase air movement.

No matter how you slice it, frost is the arch nemesis of the nursery and homeowners alike. During early spring, it is imperative that we be on watch for cold temps and potential freezes. Whether you can run continuous irrigation, or just plan on using a frost blanket, having a game plan to protect your plants is imperative. Until Memorial Day, we will be keeping our eye on the sky to ensure the best plant material possible!

A special thank you to Michigan State University’s Rebecca Finneran and Keith Mason for help with frost-free dates. MSU is an excellent source for questions on lawns, landscape, gardening and horticulture in general.  You can contact them 24/7 by clicking here. Also, check out MSU’s Enviroweather Tool by clicking here. 

/ˌrōdəˈdendrən/
     noun

First of all, “Rhodys”, Azaleas, and ‘PJMs’ are all the same!!! They are all officially part of the rhododendron genus. They are one of our most popular stars of spring. All of those stocked at Christensen’s are Broadleaf Evergreens, flower in the spring, stay leafed out all year, and start the process over again. (We do not stock deciduous Azaleas anymore but if you need them, we will get you some.)

I also like ‘Boursault’, again another purple flower (heading towards pink). ‘Boursault’ is a Rhododendron catawbiense hybrid and is short. It will reach 5-6’ max. Both are those hardier H1 hybrids.

Last on my list of Rhododendrons is the small-leafed “PJM”. ( FYI: PJM is a series developed by Peter J. Mezitt and his son in the 1930s to be exceptionally winter hardy.) They are getting very hard to find. Sometimes we get ‘PJM’, ‘PJM Elite’, or ‘PJM Regal’. They are all very similar and can work interchangeably. All have the same ‘PJM’ flowers and will reach 3-5’.

Just in case you haven’t heard about it, today is the day of the 2024 Total Solar Eclipse. We would like to think that our newsletter is so good that you feel it’s the only source of information you need, but that would mean you are just now finding out it is going to get dark this afternoon! Our main customer base is not in the arc of totality. I believe we are only going to hit 97%. So, for us, it’s mostly been business as usual. A couple of weeks ago, I heard that some of our customers are expecting an influx of people into their area of up to 2 million! There have been a lot of recommendations in the news on how to best enjoy this rare event in our area. I hope that you make the best of it. 

But since we’re in the business of plants, I’d like to ask you…
What would you consider a “Total Eclipse of a Plant?”

In the ever-changing annual market, they have bred for sun tolerance in Begonias. In recent years, Proven Winners has brought on the Double Delight and the Solenia Begonias. Both series are recommended for sun to part sun. They aren’t recommended for shade at all!

But my question is, “Why?”  So many plants are sun tolerant already.  Shade varieties are the minority and need to be sought out for troublesome spots in the landscaping.  Where are the shade-tolerant Coneflowers? How about a good tall shade-loving Ornamental Grass? Why are we breeding (in my opinion) in the wrong direction?

On the other side of the moon, are there sunny plants eclipsing themselves by taking some shade? Who is trying to bring the bright colors of roses into the dark corners of the garden? David Austin, that's who. His English rose collections have some full sun roses that will take shadier locations. Some of Dave’s roses only need 4-5 hours of sun. Ironically, one of them is called “Bring Me Sunshine”.  They are a step in the right direction of bringing more plants over to the shady side. 

Now, that’s what I call a total eclipse of a plant!

Looking for more options to keep continuity between sun and shade? Check out our resources on the website or give us a call. We are happy to help!

For, lo, the winter is past,
The rain is over and gone;
The flowers appear on the earth;
The time of the singing of birds is come,
And the voice of the turtle is heard in our land.

           ~ Song of Solomon as quoted by Ernie Harwell

My wife will tell you that one of my faults is I love every season that Michigan has to offer.  Even winter, much to my wife’s displeasure.  I do really enjoy what every season has to offer.  They all bring new opportunities, adventures, and pleasurable pursuits.

Spring offers a time for starting fresh.  Everyone is in the mood for new starts.  Windows on houses are open for fresh air to come in.  Dads are out in the garage getting them ready for summer toys to be used.  And landscaping crews are out cleaning up landscapes.  Getting ready to start installing fresh material.  Spring cleaning and spring training.

Christensen’s Plant and Hardscape Centers are no different.  Equipment has had all of its needed maintenance.  All of our winter polyhouses are open with the hoops removed.  And load after load of fresh shade and ornamental trees have started arriving every day from all over the Midwest.

Spring marks the time in the landscape industry when all of the last season is gone.  Even the memories are fading.  Allowing all of us to start the year with fresh minds full of new ideas for the coming year.  I would urge all of you to go into this year with fresh eyes full of hope, looking for those fresh ideas.  You never know who those ideas are going to come from.  Most often the best ideas come from the least likely of sources.  You need only be ready to realize it.

May your year be full of prosperity.  We are here to help all of you.

If you follow our Sticks & Stones articles, you know that as a buyer, my job is to find beautiful plants for you at a reasonable price. I think I do a respectable job at it. Lately, I have had some physical issues that have kept me from walking around as much but the salespeople at the nursery aren’t yelling about anything, so I think I am doing a good job. When I do head out to look at what just came off a truck, some things I do not look at. I just know they are fab. MAGIC!! Just kidding! No not really. Some nurseries do grow certain products that are always to die for, some other items may not be their specialty, so they need to be looked at. It doesn’t matter what nursery they come from, if it is a “Oakleaf” Hydrangea I am all over it!

I have decided this is going to be Hydrangea year again. (A year where I focus on improving my selection in a certain plant) My goal is to find a nice potted Oakleaf! You are going to see some new flavors this coming year! My best hope is with a new cultivar named ‘Jetstream’. Coming in at 5-6’ tall, it’s claim to fame is sturdy stems. I have seen these in a “can” and they look good, the kind of good that makes you look twice and go ‘dang.’ I have seen them at different locations, and they all look good. I have high hopes for these. I have not heard of them being disease resistant, but I have not seen disease issues like ‘Alice’. To counter the trouble ‘Alice’ can cause, a couple of years ago I brought in some ‘Alice in Wonderland’, a 5x5’ Michael Dirr introduction. I have seen some large potted plants, and they are beautiful. I think what I like about these the most is the flowers (on very strong stems) stick out from top to bottom looking kind of like rockets. (Truthfully it reminds me of those centerpieces you get for the 4^th of July – not at all in a bad way!).

I have small handfuls of a couple of other cultivars incoming next year.

‘Toy Soldier’ Bet you thought it was a dwarf!?!? It’s not. It will only do 4-5 x 4-5’, but it is supposed to stand up like a “Toy Soldier” on very strong stems. I also have some ‘Snowcicle’ coming in next year. It has 12-15” long panicles of DOUBLE flowers on a plant that will do 5-6 x 5-6. It is also known for its strong stems.

You will still see ‘Pee Wee’ (4’), ‘Munchkin’ (3-4’) and ‘Sikes’ (2-3’) for dwarfs. The closest thing to a “dwarf” I have found so far is the “Toy Soldier’. I have not seen anything else in a new cultivar and truly dwarf. I do, however, plan on something new in the dwarfs soon!

This year, we had a special order for some Proven Winner ‘Gatsby Gal.’ It is a brand-new cultivar and maybe a fabulous landscape plant. However, I have yet to do a double-take when I see them in a pot. ‘Gatsby Gal’ is considered a dwarf at 4x4’. It has large white flowers on very sturdy stems. ‘Gatsby Pink’ (6’) opens white and quickly changes to pink. “Gatsby Moon’ is a large “Oakleaf” coming in at 8x8 with big white mophead flowers I am going to watch these; Maybe give them one more chance. Maybe!

P.S. To those who pay attention to such crap. This is 30 years and 2 full boxes of staples for me!