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In My Garden Blog

May 8, 2008
Northern & Central Midwest
By Kate Jerome,
Pleasant Prairie, WI

Watch the volcano mulch, it's damaging to the tree.

Landscape Don'ts

At the risk of starting off on a negative note, I'd like to give some tips on things to avoid in the landscape. Sometimes we just don't realize what we might be doing wrong, and a better understanding of the situation can prevent costly mistakes.

Mulch Volcanoes
One landscape practice I see frequently is the mulch volcano. This is quite common in public areas that are managed by nonprofessionals, but I've seen a good bit of it in home landscapes as well. The intentions are as good as the mulch, but the method leaves a bit to be desired.

When mulch is applied in a circle around a tree trunk, it should be about 3 to 4 inches deep and should taper down toward the soil level as you move in toward the trunk. Mulch heaped against the trunk or stems holds moisture and can cause fungal problems.

Toping Trees
Tree topping is the practice of cutting back the main stems of a shade tree, effectively removing a good portion of the crown. Not only does it make the tree look completely unnatural, but the severe cutting causes the tree to put out a considerable number of succulent stems and foliage right at the cuts. This foliage is extremely susceptible to disease and physical problems. Most importantly, there is no reason to top a tree.

Prune to Natural Shapes
There are very few shrubs that are naturally round like a ball. Pruning is best done to follow the natural lines of a plant rather than trying to make it look like something it is not. Also, shearing the outer tips only creates a shell of foliage on the outside and leaves the inside without air or light, causing dieback.

Select Plants to Fit the Site
Planting a shrub that grows to 6 feet is not the right plant to put under a 3-foot-high window. And pruning will not keep it in top form. Trying to reduce the size of a plant drastically will only end up causing health issues with the plant, not to mention the fact that it will not even resemble what the plant should look like.

Watch Overplanting
How often have you noticed an overplanted landscape? We need to realize that open spaces are design elements, too. When choosing and installing any plants, find out how wide they will spread and then add 6 inches for the proper spacing. Crowded plants are disease prone and just plain don't look good. We choose plants because they are beautiful. Let's make every effort to keep them that way.

Thank you for pointing out all of my pet peeves of gardening,
pruning, landscaping, and planting! Your advice will help others to
preserve their plants, money and energy.

We're in a condo, but have our own flower garden. The association
has everything trimmed to a round shape, and it drives me crazy. I
appreciated the comment about over-planting because I tend to forget
that things grow.

We're in a condo, but have our own flower garden. The association
has everything trimmed to a round shape, and it drives me crazy. I
appreciated the comment about over-planting because I tend to forget
that things grow.

I prune my azaleas every year after they have finished blooming. 
And I admit that I have been shaping them like gumdrops.  What is
the natural shape for an azalea plant?  Or where can I find the best
method and shape for pruning them?

Sometimes it's hard not to get on my soapbox about landscape issues!
I appreciate hearing from someone who has the same pet peeves as
me.

Martha - azaleas have a naturally round shape, but if you prune the
branches at slightly different lengths, you will make the plant look
more feathery and natural. Be sure to use hand pruners and not hedge
shears. Good luck.

Thank you for your tips.  I have a neighbor who tops her trees and
she gets very indignant with me because I do not "top" mine.  So
thank you for reminding me that sometimes my thinking is Right On.

I appreciated your comments but what about hedge plantings?  I have
boxwood that has grown together by design and prune to keep low
under windows.  Am I creating later problems?

Can you advise on trimming the small Spirea bush? I don't know the
name of them...
These are about 2 feet tall in the fall and 4 feet circumference
after a years growth. I cut them all the way back to 6 inches above
ground.. should I not do this?

Bev - luckily boxwood is one of the best shrubs for pruning like you
are doing. They tolerate shade which means that shearing them
doesn't necessarily make the inner leaves die from being shaded out.
Every couple of years, you might take a few stems down a few inches
inside the outer "shell" to let a little more light in. Good luck!

Tom - the small spirea can be cut to the ground, but they actually
look a bit better if you take out about one-third of the largest
stems to the ground, and then gather up the rest of the stems and
cut them in half - give them a haircut, in other words. This will
make a nicely shaped shrub that doesn't look quite so formal. 

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