Some scientists predict an increase in natural disasters as a result of global warming. But somehow I think something else is responsible for all the volcanoes I see erupting in my neighborhood.

‘Volcano’ is the term coined for that mound of mulch that folks pile around a tree this time of year. Even though all the credible references advise against this, it somehow seems to be very popular. I drive through developments in which landscapers have generously heaped the mulch into a nice pyramid around every tree.

After spending a fair amount of money on new trees, you would think a homeowner would want to protect that investment. One of my neighbors recently built a series of volcanoes around the trees throughout his yard. It looks kind of cool, but just like Mount Vesuvius, these volcanoes can be deadly. That pile of mulch heats the base of the tree and holds moisture up against the bark. Not only does this encourage pests and diseases, but the tree responds by sending out new roots into that pile of mulch. Instead of spreading outward, these new roots grow inside the pile and over time can girdle the tree as they expand.

The International Society of Arboriculture recommends mulching tree root zones to help retain moisture in the ground and act as a weed barrier. But to avoid decay, disease and pests, ISA calls for mulch to be kept one to two inches away from the base of the tree. So a good gardening practice after mulching is to go back and sweep away any that might have piled up on the tree flare.

The trees will thank you.

Do you happen to know anyone who is “thin-skinned?” One icy stare and they split? That is apparently what happened to one of my cherry trees this winter.

Trees with thin bark are susceptible to splitting on days with large temperature fluctuations. It is not uncommon in late winter or early spring for temperatures to go from sunny and 50 to 20 degrees in a matter of hours. The bark expands and contracts accordingly and sometimes the thin skin of a cherry or a maple tries to contract too fast and ends up splitting. Sometimes the winter sun can heat up one side of the tree trunk while the other side remains below freezing. And this temperature differential can also cause splitting.

As with any bark damage, simply trim off the loose pieces and the tree will eventually form a callus over the wound.

Despite the large split, this snow fountain cherry still performed extremely well this spring. These white flowers cascade all the way down to the ground the first week of April each year.  And when the petals drop, this is the only kind of snow I don’t mind clearing off the walk! 

 This world can sometimes be a little chaotic. But there is no reason that needs to spread to your garden. Harmony is the design concept that ties things together. It may be the repetition of colors, shapes or textures or a unifying theme employed throughout the garden. It is an important principle that tells the visitor that the space makes sense and is pleasing to view.

Containers give the gardener a lot of creative options to achieve harmony. They are portable and easily changed out to complement whatever is going on in the beds. Here is an example of tulips in containers that match the display in the bed. This of course was conceived in the fall when bulbs were planted in the bed. The same tulips were also planted in nursery pots and sunk in the ground. This works better than planting them directly into above-ground containers that experience frequent freeze/thaws throughout the winter. The ground insulates them from wide temperature fluctuations and helps them develop in sync with the bulbs in the bed.  In the spring the nursery pots are simply lifted and placed in the containers to provide an arrangement that harmonizes with the display in the bed.

Posted by Bob Rensel

 Why do we look so favorably upon the color green? And why do we place such a high priority on developing and protecting green spaces?

There is something cool and soothing about green. If you want to lower your blood pressure, immerse yourself in a lush garden. While red and orange are exciting, green is calming. We must be hardwired to respond as such. That is why traffic barriers and caution tape aren’t green. Hot colors grab our attention while green lulls us into relaxation. And when we relax, we breathe deeper and shed the stress and tension that can take its toll on our bodies.

It’s the beginning of spring and it’s normal to look forward to the flowers and fruits planned for the summer. But let’s give credit to the foliage plants that are going to immerse our patios in green this season. Plan for the cannas, chard and elephant ears that will put the “lush” into our luscious gardens. Anticipate the ivies and creepers that will cover the barren winter landscape with a fresh green carpet. And appreciate the woodies that form the green structural elements in these spaces. We all need a little green area to which we can escape. Green is therapeutic.

Maybe that’s why the Irish consider it so lucky. 

Posted by Bob Rensel

 …for plants.  It is time for the multitudes of gardeners to take the necessary steps to stop the spread of diseases.  It is time to start sterilizing the gardening tools.

 It is really a very simple step.  Just keep a 10% bleach solution or some isopropyl alcohol in a handy jar or spray bottle wherever the tools are stored.  Spray, dip or wipe the cutting surfaces to avoid contaminating a healthy plant with pruners that were used on an infected plant.

 How often should cutting tools be sterilized?  Ideally, after pruning every plant and before moving on to the next one.  Remember that sometimes a plant can be infected before showing any symptoms.  Even if you think it is healthy, it may be harboring bacteria or viruses that your pruners can pick up and spread.

 Really?  After every plant?  If that sounds like too much sterilizing, try adopting the following sanitation schedule.

• Sterilize the cutting tools that were used at the end of the day.
• Sterilize any cutting tool right after it is used on any plant you think might be infected
• Sterilize cutting tools between plants such as roses that are highly susceptible to various contagious diseases.
• Sterilize cutting tools before pruning any valuable plant in your landscape. 

We only have two hands and I know that carrying around a bottle of diluted bleach is a pain when you are out in the garden.  But consider the potential damage of transmitting a mosaic virus from one of your dahlias to all of your prized dahlias.  Or the ramifications of spreading a rose fungus from one shrub to the entire rose garden.  Here is a picture of wisteria infected with bacterial crown gall.  It likely had this disease long before showing any symptoms.  All of our wisteria vines are pruned in the late winter each year.  And you guessed it, they all now have crown gall and need to be removed along with their infected soils. 

 There are plenty of ways our plants can catch diseases.  Let’s do our best to make sure we’re not one of them.

There is a struggle going on in my garden right now. It is the first week of March and there is still a foot of snow on the ground. But that hasn’t stopped the witch hazel from rolling out its yellow ribbons to introduce the season’s first blooms. It’s kind of a competition between the witch hazel and the lenten rose every year. This year the lenten rose is crying foul since it has been disadvantaged by snow cover since December.

I listen to all the gripes and assure my plants that no slight was intended. I couldn’t have survived the winter without the maiden grass seed heads waving at me each morning. Since November the redbud seedpods have been whispering words of encouragement to me when there is a breeze. I promise them all that I won’t get too excited over the witch hazel blooms and assure them that their persistence has helped me endure the winter months.

The truth is, I need each and every one of them. I take for granted that plants oxygenate, humidify and purify my air. But I’ll never underestimate their ability to inspire and engage me. Especially those that are so persistent in the winter. 

 …when we neglect to prune our trees.

Some trees need very little help to grow tall, straight and well-balanced. Others benefit from a little shaping. This weeping redbud needs a lot of “untangling” each winter with the help of my recently sharpened pruners.

I enjoy a good gnarly tree. Especially this time of year when the naked branching structure is fully exposed. The sculpted twists and turns don’t necessarily happen by accident. Pruning trees is an art, especially when dealing with the gnarly, twisting and weeping tree varieties.

Late winter is a great time to prune trees. By removing the end growth of a branch, you are forcing the side buds to take over. Redirecting growth is that simple.

It certainly helps to start with a young tree. There is usually enough growth from the previous season that there is no need to bend, wire or force branches to grow in a certain direction. Instead, simply encourage the new growth that you like and remove the rest. With a little vision, you can determine which branches will grow to become the beefy arms of the sculpture. Selectively thin out competing branches and make cuts each year to flex those arms in a manner that you find appealing.

When dealing with a tree that just wants to weep, consider allowing a few new shoots to grow upwards so that you can fold these twigs back over the tree to create a layering effect to the branching. Art is subjective. But the nice thing about this art form is that it is also alive. You can revisit your artwork every winter and change or improve upon it as you see fit.

Posted by Bob Rensel

When I started working as a professional gardener, people would ask me to identify trees in their yard. Needless to say, I shrugged my shoulders a lot, especially in the winter. Since then, I have learned a bit from my gardening colleagues, from books and from on-line resources. I’ve found that if you know what to look for, you can usually figure it out.

Buds, for instance, have a lot of varying characteristics that will help ID a tree. For starters, how are they arranged on the branch?  If they are opposite each other, that helps narrow it down to a handful of likely candidates here in northern Ohio. Maple, ash, buckeye, dogwood and lilac have opposite bud arrangements on their branches.

Posted by Bob Rensel

Is a garden better than any other designed space? Horticulture therapists can explain the healing powers of plants and landscape architects can describe the therapeutic attributes of a well-designed green space.

But wait a minute. Won’t a feng shui designer help you achieve that same tranquility and balance in your living room? And a home organizing consultant can relieve the agitation of a cluttered basement or the chaos of a hopeless closet in disarray. Why should a garden space be considered more beneficial than any other well-designed space? After all, there have been many snowy nights lately during which I find peace in my favorite stuffed chair in front of the fireplace. Add a good book and a glass of wine to that scenario and one might think it’s the perfect stress-free environment in which to recuperate from a hectic day. How could this setting be any more calming and therapeutic?

Well, let’s see. It would be nicer if there were fragrant lemon tree blossoms next to my chair and a hedge of lavender and rosemary for me to brush up against when I moved around. The calm generated from these aromas could be enhanced with a beautiful sunset or interesting cloud formations moving across the sky. But I can’t see those from my living room. And while it is peaceful in front of my crackling fireplace, I kind of like the sounds and sights of wildlife. Bird song can be very tranquil and the simplicity of hummingbirds, blue jays and squirrels are entertaining distractions in our complicated lives. While I like the colors in my living room, they aren’t as dynamic as those that unfold in the garden. Chocolate heucheras, stained glass coleus and bold sunflowers just begin to describe the changing palette manifested in the garden. The ceiling fan can move some air, but it’s just not quite the same as a gentle garden breeze rustling the ornamental grasses. Just thinking about fresh air makes me want to breathe deeper.

Everybody’s different and one person’s paradise might not be as ideal for someone else.  But research shows that gardens generally lower stress levels, improve memory and alertness and promote healing and self esteem.  That’s why I prefer the back yard patio chair when the weather is more accommodating.  Until then, the stuffed chair in the living room will have to do.  Where’s that latest seed catalog?