Kansas City gardeners can breathe a sigh of relief that we did not reach the forecasted lows last of week of -20. For many years, we have been lulled into thinking that we may have shifted into zone 6. However, it only takes one very cold night to ensure that we are truly a zone 5 area. The plant hardiness zones are based on the average lowest temperatures for a 10 year period. We are about to reset those zone maps if we approach -20 degrees. Plants are rated to their zones based on laboratory tests as well as the experiences of growers in the fields. Plants rated as hardy to Zone 5 generally survive low temperatures of -10 to -20 degrees. Zone 6 plants are only expected to survive to -10 degrees.

Of course, zones are only part of the answer to how your plants will during this cold snap. Zones define large areas, but not small microclimates that exist around your home. If your plants lie in a low lying area or out on a windswept plain, they are going to have considerably more exposure to cold temperatures than if they are nestled in a protected courtyard, along a south facing wall or on the wayward side of a hill.

That being said, many plants in Kansas City are going to suffer from this cold. Dan Simmons of Show-Me Horticulture and I were talking about what effect this could have on plants. We both agreed that a few of the standouts are plants that have started being popular at retail nurseries lately despite being unproven (or proven poorly) to thrive with very cold winters such as this years. A few plants that are going to be strongly affected are southern Magnolias such as Bracken Brown Beautys, crape myrtles, azaleas, rhododendrons and other broadleaf evergreens. These are all plants better suited to Zone 6. They may have done quite well in Kansas City the last several years, but will be well-tested this winter to see if they have enough protection to survive the extremes.

Even a few proven plants will still be stressed. Boxwoods, yews, and many broadleaf evergreens will likely show some damage come next spring from the prolonged cold weather combined with dry winds that we have experienced over the last several weeks. Another group of plants that will very likely show some signs of stress will be some of the ornamental grasses such as the ornamental fescues, the Japanese Silver grasses and the fountain grasses. Some of the larger trees such as Zelkova, Golden Rain Tree, dogwoods and redbuds could suffer some superficial damage to outermost branches as well.

Unfortunately, there is not much you can do to protect your plants now. If your plants went into the winter relatively healthy and unstressed they will have a much better chance of survival than if they were stressed already. Newly planted plants will have a harder time than older, more established plants. The snow that is insulating the ground is the biggest protection we have right now and this can be bolstered if you are inclined to pile snow around the crowns of your most valuable plants. Another option that can be helpful is to build a windscreen around broadleaf evergreens to help protect them. Lastly, to help plants bounce back as much as possible, give them a good slow soaking of water as soon as the ground thaws and repeat at least monthly throughout the winter. This will help immensely as your plants begin to heal their wounds.

This spring will be quite revealing as we learn a lesson of what plants truly are able to survive Kansas City’s coldest temperatures. We will be better gardeners if we observe and learn from what nature teaches this week and choose plants that will thrive in Kansas City even during when it is at its coldest.

If you have any questions, please feel free to visit me at www.HamonsLandscaping.com or posting questions as a comment to this blog post. I enjoy talking to other plant lovers and answering any questions you might have.

Kansas City has had a record snow storm this week. Gary Lezak reports that most areas received between 10 and 14 inches in Kansas City. Although snow can be a hassle for traveling and moving around in, it is GREAT for plants.

Not only does the snow insulate the plants crowns from widely swinging temperature extremes, it also will add important winter moisture applied slowly and evenly.

You can even help your plants out with extra moisture by choosing where you toss the snow when shoveling your walks and driveways. By piling it on flower gardens and around trees you will be giving them extra moisture. However, if you used any kind of deicer or snow melting product, be very careful as concentrating these in one area could be harmful. Here is a great article on using deicers around your plants.

About the only time snow can be damaging is if it stays around for weeks and weeks without melting it can cause some disease issues. However, in Kansas City we rarely see snow stick around for longer than a week before it melts away.

So enjoy the snow and rest well knowing that your plants are well taken care of while you enjoy them from the outside.

Frost coming to Kansas City Landscaping

Many of the plants we love to plant in the fall are chosen especially because they are fairly frost tolerant. Flowers such as pansy, kale, ornamental cabbage, Hardy Mums are all frost tolerant and can extend the beauty of your garden by several weeks. A complete list of frost tolerant plants

Your lawn will not be so strongly affected by the frost. Its correlation with lowering soil temperatures will have an effect but the actual grass tissue will likely not be harmed by the frost in any way. The only caveat to this is that if you walk on frosted turf you can damage the grass blades and they will turn brown if conditions are just right. This is because when you step on the turf while frost is on the grass, you can explode the frozen tissue causing it to die away. This is just cosmetic damage but can stay visible for a long time until next Spring when new growth replaces the killed tissues.

My primary suggestion when dealing with fall frost is to allow nature to decide when its time for this years growing season will end — knowing some seasons will be longer and other will be shorter.

There has been a near media blitz this year informing Kansas City Gardeners.  However while looking at an Overland park landscape last week I saw more mulch volcanoes. 

I can fin no excuse that there are professional landscaping companies out there who still continue to pile mulch around trees.  It make me very sad to know that there continues to be companies and residents who are having there landscaping ruined by either ignorant or careless landscapers.

Here you can see the results

Notice how the bark has already started to rot away.  The darker color indicated the bark that was dying and ready to peel off.  Additionally, the picture doesn’t show it well.  However there were also multiple insect holes in the bark under the mulch.

The old adage – Plant a $5 plant in a $25 hole holds true in Kansas City’s Landscaping.

On a  recent project I planted over 70 Hostas, Coral Bells and Astible in an existing garden.  This garden had gravel already put down and the soil underneath was not great.  Normally, when making a new bed it is best to amend the entire bed with high quality organic compost.  However, this is not possible in a bed that already is covered with several inches of gravel.  So you have to amend the planting hole.  You have to be careful when doing this though.  You have to make the hole quite large in comparison to the plant you are planting.

Start by removing the rocks from where you are going to dig the hole.    Notice that the hole is about 3x as big as the plant itself.

The laws of geometry then say that you are not just increasing the volume of the hole by 3 – but closer to 9x the original plant container size so you will need to add a considerable amount of extra compost.  I use a high quality compost made from landscaping debris.    It is tested regularly to ensure its purity of toxins. 

After mixing the compost with the native soils – carefully plant the plant.

With Coral bells specifically – Be careful of their crown and make sure that crown of the plant is carefully planted just below the surface.

Then slide the rocks back in place around the plant.

Each plant can take upwards of 10 minutes to plant carefully and correctly.  So it truly is a $25 hole for a $5 plant.  However, The long term growth and vigor of the plants will be worth it to the customer.  However, with 70+ plants to plant – it is not a quick job.

Here are some general guidelines for the frost hardiness of plants in Kansas City Gardens

Vegetables

Annuals

Hardy	Tolerant	Tender	Warm Loving
Corn Flower	Black Eyed Susan	Aster	Ageratum
Ornamental Cabbage	Calendula	Nicotiana	Balsam
Pansy	Coreopsis	Petunia	Begonia
Primrose	Dianthus	Scabiosa	Celosia
Violet	Snap Dragon	Statice	Cosmos
	Sweet Pea	Sweet Alyssum	Impatiens
	Torenia	Verbena	Lobelia
			Marigold
			Portulaca
			Phlox
			Salvia
			Vinca
			Zinnia

Thank you to the University of Purdue for supplying information needed to create this informative chart.

Rain Gardens can be a great way to solve landscaping problems in Kansas City.  landscapers can use them to effectively deal with drainage issues that have been plaguing homeowners for years and are often  better solution than simply sending the water further down the hill to the neighbors yard.

Here is a concept rendering for a rain garden I will be installing soon in a customer’s landscape.  I will chronicle this build and update the blog with its progress including before and after shots.

If you have any questions about rain gardens please be sure to leave a comment and I would be happy to share what I know,.

This is on of my favorite trees to plant in Kansas City.  ‘Emperor I’ is very similar to ‘Bloodgood’ in growth habit, although this tree has a lighter almost translucent quality to the leaves. It holds its red color well throughout the summer months, and has a brilliant crimson fall display. It grows to about a maximum of 15 feet tall and 7 feet wide.    This tree does very well in Kansas City landsapes.  it does best if protected from hot afternoon sun.