A Blast From The Past

Anyone familiar with my garden knows I am a fan of evergreen plants. That makes sense. I live in a gardening zone notorious for its lengthy off season. Not only are our winters long, but our early spring and late fall can also be cold and anything but green. So I grow yews, and arborvitae, and of course, boxwood. A landscape that has something to say all year round is a good landscape. I would say the signs of spring probably presented themselves seriously a week ago or so.  The maples in the tree lawn are dusted with their chartreuse blooms. The grass began greening up. The hydrangeas in the foreground of the picture about are just beginning to leaf out. My large concrete pots are more visually important now than they will be at any other time during the season. They are beautiful, just so. unplanted. But the front yard landscape at this moment is really all about the boxwood. It is green and robust in much the same way it has been all winter.

The boxwood is quick to shed its winter coloration, as are the arborvitae, yews, and the old spruce in the background of the above picture.  I never tire of any of the evergreens, as the weather from one event to the next changes their appearance. The surfaces of the evergreens shimmering with rain drops in the spring is as beautiful as those same surfaces hatted by leaves in the fall, and snow in the winter. They are a crucial part of my landscape.

The role they play is never easier to see than it is now.  I can walk between the pruned and leafless hydrangeas, and see what a prominent role they play in the landscape. And I can even more appreciate the longevity of that service. Most of my boxwood at least 15 years old.

But cultivating evergreens in very cold climates comes with a price. The street side of my boxwood paints a different picture.  Extremely cold and windy winters can damage them. It is important to water evergreens well before winter. Once the ground freezes, the roots will have no opportunity to absorb water again until spring. Needled evergreens present very little surface area to the elements. That structure helps them to naturally conserve moisture over the winter. Though boxwood leaves are small, they are much more broad and thin compared to evergreen needles.  Extremely cold and windy weather can can quickly desiccate the leaves. If you have ever had a cut boxwood wreath on your front door for the holidays, you are aware of how incredibly long cut boxwood branches stay green. The same is true for cut evergreen boughs, or Christmas trees. This damage I am seeing now occurred months ago. The return of the warmer weather is revealing the result of terribly cold weather we had the end of January.

The polar vortex which occurred in January of 2019 is again part of the conversation. The intense cold that gripped a significant portion of the northern midsection of the US set records for cold and wind chills in a number places. I do know what I was doing then. I stayed at home, and only let the dogs out for a few minutes at a time. It was the coldest recorded winter temperature event for Chicago in 25 years.

From Wikipedia   “In late January 2019, a severe caused by a weakened around the Arctic hit the and , killing at least 22 people. It came after a brought up to 13 inches (33 cm) of snow in some regions from January 27–29, and brought the coldest temperatures in over 20 years to most locations in the affected region, including some all-time record lows. In early February, the polar vortex moved west, and became locked over Western Canada and the Western United States. As a result, February 2019 was among the coldest and snowiest on record in these regions. In early March, the cold once again shifted east, breaking records in many areas. In mid-March, the cold wave finally retreated, but combined with above-average temperatures, precipitation, and a deep snowpack, ensued in the Central US.” Yes, it was a vicious weather event.

The impact of that extremely cold weather is beginning to be seen. I was faint with surprise when I saw the entire top of this picea mucrunata was dead. If you look up the phrase  “top of my spruce is dead”, most articles cite winter winds and extreme cold first. I see no eveidence of disease or insect damage. Could the polar vortex be to blame?

Of course the time to think about safeguarding evergreens from winter damage is in the fall. I have never seen damage on the boxwood cultivar “Winter Gem”. I plant it extensively now. I rarely plant “Green Velvet” anymore, which is the cultivar I have at home. Thankfully it rarely gets any damage, as I live in a neighborhood where the wind is broken by multiple buildings that surround my landscape, and the sun is tempered by large trees. I have never seen winter damage on boxwood that has been sprayed to the dripping point with VaporGard in the fall. A dry day when the daytime temperature is above 50 produces optimum coverage. Later in the fall, a windbreak of burlap can help. I would have never thought to protect my spruce, but maybe I should. A last bit about the boxwood.  Given the extreme cold we have had in the past years, the price of boxwood has skyrocketed. Replacing my damaged boxwood will be very expensive. Hopefully I will remember this day come the fall.

On a positive note, the below freezing temperatures and snow forecast for this past weekend never materialized. I am pleased to report my magnolia stellata is still in full bloom.

Winter Protection For Boxwood

Detroit-Garden-Works.jpgBoxwood is one of the most versatile and robust growing evergreens available for planting in my zone. There are a number of great cultivars.  Green Velvet matures at 3′ by 3′, and keeps its great color all winter. Green Mountain is virtually identical to Green Velvet, but grows to 4′ tall by 3′ wide. Buxus microphylla koreana, pictured above, is hardy in this full south sun location, and can grow to 5′ by 5′.  The winter color is a dull orangy bronze. Winter Gem boxwood is incredibly hardy, and grows slowly to about 4′ by 4′. The leaves are smaller, and narrower than Green Velvet.

DSC_4001There are lots of other hybrids available.  Vardar Valley is an outstanding hardy cultivar of buxus sempervirens. It matures at 1′ to 2′.  The leaves have a distinctive blue green color.  As it is a slow growing variety, it is not routinely offered for sale at local nurseries.  Most of the boxwood sold in my area is grown in regions where the season is long enough to permit 2 flushes of growth per season.  This means nursery can get a salable product faster.  Boxwood is graded by width-not by height.  A boxwood takes about 7 years to grow to an 18″-24″ size.  This makes them relatively expensive to buy, compared to other ornamental shrubs that grow quickly.

MG 2013 (29)Boxwood is indeed a versatile shrub. They make great hedges, as their growth is uniform, and they are very tolerant of pruning.  That tolerance makes them an ideal subject for living sculpture. Boxwood pruned into spheres, squares, cones and cylinders are striking and delightful.  The large boxwood in this landscape will be kept pruned in spheres.  The small boxwood will be allowed to grow together, and will be pruned flat. This garden will have a much different look in a few years. All of these boxwood are Winter Gem.  The fine textured foliage makes them ideal for pruning into a formal, strictly geometric shape.   DSC_1801Boxwood are quite friendly to other plants.  Provided care is taken in the selection of a cultivar for a specific site, they will stay in bounds. These boxwood rectangles are a beautiful foil for the clipped espaliered crab apples. If the face is pruned on a very slight angle out from top to the bottom, they will stay green all the way to the ground. A boxwood which is hard pruned into a specific shape will stay green on the interior.

boxwood-green-velvet.jpgBoxwood makes a fine tall ground cover under a tree.  They are quite shade tolerant. A small landscape such as this is all the more interesting for a change of level.  These boxwood are a welcome visual intermediary between the ground plane, and a linden which has grown to substantial size. That they are shade tolerant means they can be sited in lots of places.  Naturally grown boxwood make a lovely backdrop for ferns, hostas and shade tolerant perennials.  A boxwood provides a green backdrop for the earliest of perennials to appear in the spring.  The small textured foliage makes them a great companion for the bigger textured hellebores, and European ginger.

Aug 31 2013 (20)A boxwood would go so far to oblige a gardener who wishes to grow them in containers.  They do need large enough containers so there is room to grow.  The root ball of a decent sized and well grown boxwood might be larger in diameter that its leafy component.  Boxwood in containers need special attention to proper watering. They need to be well watered prior to freezing weather.  They will rely on water stored in the stems and leaves to survive they winter, as the water in the container cannot be absorbed when it is frozen.  Boxwood in ground has much more widespread moisture available to its roots, especially given how long it takes for the ground to freeze to any significant depth.  A boxwood confined to a pot needs regular water.

boxwood-hedge.jpgPruning boxwood takes more than a good eye.  A great job invariably involved the setting of level lines.  Relatively level boxwood has a forlorn and unfinished look.  This boxwood has been pruned level with the horizon, even though the driveway drops down to the street.  The boxwood at the bottom of this drive is quite a bit taller than those plants at the top.  Level boxwood has a serene and solid look to it.

August 12 2013 (11)Boxwood can help provide structure to a garden.  This densely growing shrub provides a simple and strong contrast to the garden elements.  This pruning is loosely formal, and softens the stone wall behind them.

Aug 31 2013 (18)I have written about boxwood plenty of times before – I do like them.  It was painful to see how many boxwood in my area were severely damaged or killed outright by our last winter.  Some were crushed by the huge snow loads.  Others in more exposed locations were damaged by the extreme cold.  That cold, in conjunction with sun and wind burned the leaves. Leaves that were completely desiccated, died. It took the coming of the spring weather to see how terrible the damage truly was.  Some of the boxwood at the shop died outright.  The damaged portions will take years to recover.

July 5, 2012 035If you have ever hung a boxwood wreath on a shaded door for the winter, or used cut boxwood in winter pots, you know those stems will dry out, but stay green until the temperatures moderate.  Like many evergreens, by the time a boxwood shows signs of stress, it is too late to remedy the problem.  Now that fall is approaching, I would urge anyone with boxwood in my zone to spray them with an antidessicant.  An antidessicant is a waxy coating with will slow the evaporation of water from the leaves in the winter.

boxwood-spheres.jpgI have heard talk that this winter looks like it may be a very cold winter.  Something like last winter.  Though boxwood is hardy in this zone, extreme cold, sun, and drying winds can damage them.  Though a boxwood may grow out of winter burn, that look is unsightly come spring.  If your boxwood are 15 years old, it will be very expensive to replace dead plants with new plants of the size you already own.  Last winter was dramatic evidence that winter protection for boxwood is a good idea.  photo (43)I recommend Vapor Gard.  It is widely used as an agricultural antidessicant. The main ingredient is pinolene, a natural polymer made from pine pitch.  It can significantly reduce winter burn.  You can buy it, dilute it 1 part to 20 parts of water, and spray it on your boxwood. If you have lots of boxwood, your tree care company can spray this for you.  It is best done on a dry day, before the weather drops regularly into the low forties.  The polymer coating will protect those leaves over the winter, and help them retain moisture.  Vapor Gard is a natural and non toxic spray widely used on crops, including cherries.  It is an easy way to protect your investment. Do read the label-it is not appropriate for every and any plant. I plan to spray all of my boxwood with it soon; one application will protect them the entire winter. The boxwood pictured above from this past spring-heartbreaking.   Interested further?  

Был найден мной интересный web-сайт со статьями про полив газона.
youtube.com/watch?v=un5wf0Wl8M4