Even though Red maple is on the Fall Hazard list, the Freeman Maple hybrids (Acer x freemanii ) like Autumn Blaze® (‘Jeffersred’) are not considered a poor risk. Being a cross between silver and red maple, they are tough, fast growing, adaptable trees. They are drought tolerant when established and hardy to Zone 3, making them good candidates for fall digging. Norway (Acer platanoides) and Sugar (Acer saccharum) maple also tend to move well in the fall.

Some others to consider are Ginkgo and ‘Ivory Silk’ Tree Lilac (Syringa reticulata) - even though that last is not technically a shade tree we do see demand for them in landscapes where space is at a premium.

Any of our knowledgeable staff would be happy to help answer questions or give you the most suitable substitutions regarding fall hazard trees.

Visit these links for more information about Fall Hazard trees:

Fall Hazard tree lists explained (Sticks & Stones, Jeff Good)

Transplanting and a Deeper Look at “Fall Hazards” (NYC Parks Director of Street Tree Planting Matthew Stephens and Taking Root Editor Michelle Sutton)

You may have heard of a new fungus that has been damaging and killing boxwood in the US. It was first identified in Connecticut in 2011. Called Boxwood Blight, it has now been seen as near as Ohio. It has been predicted that it will continue to spread. Spores can be transferred by physical contact, splashing water, or wind.

Christensen’s Plant Center is taking the necessary steps to make sure that we have clean boxwood in stock for you at all times. This means following the best practices that have come from growers and distributors across the country.

Boxwood Blight is easily transferred by physical contact. Even brushing up against an infected plant means that you can transfer the fungus onto other plants later that day. To that end we must ask that you observe the following when visiting Christensen’s Plant Center.

• Please do not bring Boxwood plants or parts of a Boxwood into CPC. We will continue to do our best to identify any plant material via a photograph, but we can not have possibly infectious plants brought into our clean nursery.
• We will no longer accept any returns of Boxwood for any reason. Again, we cannot accept materials back once they have left our clean environment.

These practices are for your success as well as our own. Maintaining a clean facility ensures that we will be able to provide you with material that is free of Boxwood Blight for all of your projects now and in the future. Thank you for your help!

In the links below are PDFs with more information about this disease.

MSU Extension - Boxwood Blight Disease in North America (2.33 MB)

CAES - Boxwood Blight - A new disease for Connecticut and the U.S. (1.05 MB)

Guess what! We sell these! I don’t care how you say ‘em or spell ‘em as long as your check clears. I’m pretty sure my boss would agree with me. Hardly a day goes by that we don’t get contractor lists of hybridized and spell-’em-as-you-hear-’em names. I personally love the challenge! And yes, we do sell junipers - and yews.

In particular, Christensen’s sells a number of species of upright Junipers, the Eastern Redcedar. They are somewhat interchangeable with Arborvitae. Junipers require and tolerate hot, dry, sunny conditions but can have difficulties in poorly drained areas. They can be planted as backdrop accent evergreens or hedged into a living fence. A caveat is to avoid planting them too close to some members of the Rose family such as Crabs, Pears, Hawthorn, and Quince due to host/parasite rust occurrences.

The species of Juniperus that Christensen’s typically stocks are:

J. virginiana

• ‘Keteleer’ - a soft, green needle with loose habit; often used for native plantings
• ‘Taylor’ - a newer introduction with a bluish-green, tight habit; similar in form to Thuja occ. ‘Emerald Green’

J. chinensis

• ‘Blue Point’ - a bluish-green, full habit; often used for topiary
• ‘Hetz Columnaris’ - green needles with broad, architectual habit; best of the fruiting varieties we stock
• ‘Spartan’ - a green needled variey with a tight, upright habit

J. scopulorum (Rocky Mountain Junipers)

• ‘Blue Arrow’ - a soft, bluish upright with a very tight form
• ‘Skyrocket’ -a grayish, green variey similar in form to ‘Blue Arrow’
• ‘Wichita Blue’ - a broad, very blue form with very soft growth, but a rugged look

Availability for this genus is not quite as reliable as Arborvitae. We usually see periodic waves of uprights appear throughout the season. Junipers do, however, offer a greater range of color when compared to Arborvitae.

Next time you need an upright evergreen, ask to see some of the varieties just mentioned. Exact spelling not required!

Should I be fertilizing my trees and shrubs in August?

Ask five experts that question and be prepared for five different answers, at least that happened to me. Regardless of the type or size of your new landscape, maintenance will be required to ensure it stays healthy and looking the way it was designed to look. Although 95% of all problems with new plant material can be attributed to improper watering, fertilizers are going to play a big part in getting things established and staying healthy.

Early spring and late fall are obviously your major fertilizing moments, but let's look at right now. New plantings will be aided by the use of some starter fertilizer, especially at new housing and businesses where a lot of good soil has been stripped away. Some cities have poor soil to begin with, lacking nutrients to give plants a good start. We carry some great organic starter fertilizer containing bacteria and mycorrhizae to increase root mass and help avoid transplant loss due to difficult conditions. Light application of these starters and plenty of water will be key during this month.

Fertilizing established plants in August is a little tricky. To avoid stressing the plant, avoid fertilizing during drought or heatwave conditions. Know your soil and fertilize only when plants are truly nutrient deficient. Why? Because new growth forced by fertilizing during this period may not harden off before the onset of winter resulting in tip dieback that won't show until next spring sometime. That's a phone call you won't want to get!

Come by our store and we will help you choose the best product for your particular situation.

Colorado blue spruce is one of the most popular evergreens we sell. The straight species is usually green, but the cultivar 'Glauca' ranges from bluish-green to an eye-popping silvery blue. The color is genetically determined and before grafting ornamental trees became the norm, the brightest blue seedlings were known as "shiners" and were selected out and sold at a premium. Now we have numerous cultivars with consistent, bright blue color. 

So why might you get calls from customers complaining that their expensive blue tree is turning green? Firstly, the blue color is only present on the new growth, weathering off in time. Pesticides can strip off this waxy blue coating from the needles as well. Other culprits can be air pollution, or poor growing conditions that keep new foliage to a minimum.

Once the blue color has worn off the needle, nothing will bring it back and the tree is going to look green until that flush of new growth each spring. However, you can encourage the best possible color by providing ideal growing conditions and care. Spruce prefer moist, well-drained soil, and you may fertilize established trees in early fall or mid-spring.

Horticulturally speaking, the color blue is rare. So rare, that many of the flowers we call "blue" are in fact... purple. Blue iris? Purple. Blue roses? HA! Purple - and weak at that. Syringa, Campanula, Lobelia, Hyacinth, Baptisia... all have varieties CALLED blue, but they are... purple. I found this quite confusing when I started in the nursery business. Apparently we gardeners are DESPERATE for blue in the garden and we will call anything close "blue".

This tendency extends to foliage as well - blue spruce, blue juniper, and blue hosta, are all rather more silvery than blue, with the added insult of the color wearing off with weather and time! I still chuckle about the customer I had on the retail lot one day, who accused us of spray-painting the 'Moerheim' spruce because, "Look! It rubs off!" There wasn't much I could say because he was right, it did.

There ARE a few truly blue flowers we can grow in Michigan. Amsonia, Delphinium, Virginia Bluebells, the annual 'Black and Blue' Salvia, Forget-me-nots, Sisyrinchium, and Ceratostigma all have excellent blue flowers. Scilla siberica is a minor bulb that naturalizes and can give you an ocean of blue flowers every spring. Chionodoxa's pretty good, too.

In shrubs you can try Caryopteris - wait, that one's a bit on the purple side - heck, it's barely a shrub, more like a woody perennial. Hmmmm. Hibiscus 'Blue Chiffon' is pretty blue. Almost. OKAY, OKAY, FINE. You want blue? You'd best be planting Hydrangea. The old favorite, 'Nikko Blue' has been surpassed by newer cultivars like Nantucket Blue™ and The Endless Summer® line, with the original Endless Summer®, Twist-n-Shout®, and BloomStruck®  all of which bloom on both old and new wood. These plants can be coaxed into producing nice blue blooms with the proper soil pH.

So you do have some options. And take those photos of bright blue-flowering plants on Pinterest with a grain of salt. Most of them are Photoshop. Or perhaps dyed like those poor Phalenopsis orchids at the grocery store.