I hated it when Grandma would pinch my cheeks as a kid. But that was her way of showing affection. Well, you can show the same affection to your plants this time of year. 

All too often we buy beautiful flats of annuals and each plant has a solitary bloom. Don’t be afraid to pinch it off. Plants have a natural defense mechanism to redirect hormonal growth to the side shoots if the tips are broken off. This leaves you with bushier plants that can then be spaced farther apart. So hey, pinching plants lets you pinch your pennies as well!

Gardeners have been pinching their mums for years. But look around your garden for any plants that have a tendency to be leggy. Pinching can delay bloom times depending on how far along the buds have developed. Some gardeners use pinching as a strategy for rescheduling bloom times in their gardens.

Some folks just can’t bring themselves to pinch off all their beautiful annual blooms. After all, we waited all winter to get some color into our garden beds. Maybe you are afraid of damaging a favorite perennial by pinching it back. Then try experimenting with pinching half of the stems. This will allow the remaining blooms to follow their normal course and create a second wave of blooms from the pinched-back stems.

Gardening is all about trial and error. So, try pinching back your tomato plants when they get to the desired height. And if your favorite recipe calls for a pinch of basil or a pinch of parsley, don’t just arbitrarily remove an outer leaf. Rather, pinch back a center stem to force lateral, bushy growth. Before you know it, pinching will become second nature…like it was with Grandma.

Posted by Bob Rensel

When selecting plants for a garden site, quite a bit of emphasis is placed on flower color and plant size. Sometimes gardeners will be looking for certain fragrances or foliage textures. It is also good to step back and consider the overall form of the plant. Will the plant swell up like Star Wars’ Jabba the Hut as is the case with this blue spruce? When planting a young specimen, don’t put any other permanent plantings right next to it so that it has the room to develop those rolls of fat.

There is something mysterious about the Nootka false cypress form. I envision an old man in a cloak.  Or perhaps the creatures from The Village that the elders were so worried about.  Either way, I personally like seeing this specimen partially obstructed in a garden bed instead of standing out on its own. I guess that add to its mystery if it can be seen emerging from grouping of plants.

How about that giant octopus that grabbed the sub in Voyage to the Bottom of the Sea? There are plants with similar tentacle-like forms that can twist their way through your garden. Just don’t accidentally get in their way while gardening. I have a giant limbed-up yew that is obviously going to grab whatever it can reach.

A weeping katsura can be a dead ringer for the Creature from the Black Lagoon. Can’t you just imagine the algae dripping off of him?

Okay, so it takes a little imagination to see these creatures in plants. But when abiding by “the right plant for the right site” rule, it is very helpful to step back and consider the ultimate form of your new selection.

These and many more sci-fi plant forms are on display out in front of the Cleveland Botanical Garden in the Campsey-Stauffer Gateway Garden.

Posted by Bob Rensel

Slugs are an insect that I’d rather not see in the garden. I think they are destructive, slimy and disgusting. As a matter of fact, I can’t even look at my wife’s escargot in a restaurant, because it reminds me of garden slugs.

So, this is the time of year, I try to protect my susceptible plants from slugs. I would rather not deal with toxic chemicals and baits in my garden. And I have tried the beer-in-a-dish tactic. I found more slugs on the underside of the dish than were actually in the beer. So, I only caught a handful compared to the thousands that I know are out there in my clay soil. 

One control method that I see recommended a lot is hand picking slugs off of plants at night. I wonder if the people that write this actually go out at night and do this. 

The Ohio Extension Service has a nice fact sheet on slugs. But an easy control method not mentioned is sand. You can buy products like diatomaceous earth and sprinkle it around your hostas. But sand is cheaper and lasts longer. It has the same effect of creating a course or gritty surface that the slugs won’t crawl over to get to the plant. If I start to see slug damage on plants, I pull out the sand and sprinkle it around the base. If I do this early in the season, the plants then fill out and hide the sand from view.  It works for me.

Posted by Bob Rensel

 Some of my favorite plants will reseed each year if the conditions are right. Sweet Alyssum comes back each year in my garden thicker than the last.  I am careful in early spring not to till or disturb the soil so the seeds can germinate. Then, by mid-May, I can dig up large clumps of the new seedlings and use them in other beds or in containers. It comes back so thick that it is an effective weed barrier. But I noticed that the purple-colored variety does not reseed as vigorously as the white. 

I use pre-emergent herbicides in some of my beds to cut down on the amount of weeding. But I skip the beds that have the plants I want to reseed. The lenten rose reseeds quite nicely in some of my beds. Even though it takes a few years for these seedlings to mature into flowering plants, it is worth the wait. These are expensive plants, so I welcome the additions. I skip the pre-emergent application in the coneflower beds as well. If an area has potential to fill in from reseeding, I tolerate all the weeding until it thickens up with the desired plant. 

Foxgloves, columbines, lavender and cleomes are all welcome reseeders in my garden. Others, like switch grass and sweet autumn clematis are too aggressive for me. Unlike alyssum, which reseeds just in the area of the parent plant, the sweet autumn clematis seems to have a wide range for reseeding. Being a climber, it must have a better opportunity to get caught up in the wind. New plants show up 30, 40 and 50 feet away from the original location.  It never ceases to amaze me how it can take hold under a large shrub and hide from me for a couple years.  You have to admire its persistence, even if it is not a welcome reseeder.

Posted by Bob Rensel

Removing Some of the Guesswork in Gardening

I recently joined a Dahlia society, because I like the plant so much. My success with Dahlias was part luck since I didn’t always follow the recommended growing requirements. Since then, I’ve come to learn that a wealth of information about Dahlias is available online. Instead of settling for what the local garden center has in stock, online resources can help you find the right colors, sizes and varieties of plants needed in your garden. And, of course, they can also link you up with a supplier.

For instance, I needed some bold reds and yellows for a tropical display this summer. I visited the American Dahlia Society website and used the search engine. I was able to select plants by flower color, size and shape. I was also able to narrow my search to proven winners that have won a minimum number of awards.  Martinique, for instance, has 4 to 6" dark red blooms in the semi-cactus flower form.  Now that’s a red! 

The Perennial Plant Association lists all of its “Plants of the Year” on its website. These are also no-brainer plants that have won accolades because they are tough performers year after year.

The online resources are endless. When I re-seeded my front lawn last fall, I was able to search online for the blend of grass seed that best fit my need for wear tolerance and drought resistance.

But don’t bypass your local garden center altogether. Tell them about the award-winning and proven varieties that you are finding online and encourage them to stock them. It is in their best interest to keep customers satisfied by selling reliable plants.

Posted by Bob Rensel

I’ve learned from experience that some plants will flop on me if not supported. It is disheartening to wake up in the morning after a stormy night to find the dahlias beaten down and broken. One year, my peonies came into bloom just before a rainstorm hit. At least I got to enjoy the blooms for a couple hours.

While we are glad to see growers develop plants with bigger and more prolific blooms, we also have to be prepared to support the added weight that the stems might not be able to bear in rain and windstorms.

Instead of using commercial stakes that might stand out in a landscape, let me suggest a natural look when staking. My favorite stake source is from the arrow wood Viburnum stems. I thin and cut these back every year. And as the common name indicates, these branches are long and straight.  Because of the opposite branching structure, they also provide a nice Y-support for caging in a plant that might want to flop. I circle my peonies with them, and they virtually disappear as the peonies grow into and through them. But they do the job.

As an added benefit, sometimes the stakes that I use from tree and shrub cuttings will leaf out themselves and might even flower. So, consider recycling the branches you prune in the spring and put them to work in your yard throughout the summer.

Posted by Bob Rensel 

I like to play a little game in one of my gardens called “Hide the Concrete.” You see, it is a rooftop garden over the 200-car garage here at the Garden.  This garden can really heat up on a sunny day. My job is to cool the space as much as possible with greenery.

The walls are the easiest to hide. Weeping cherries and a Lavender Twist redbud cascade down from above and New Dawn climbing roses, Sweet Autumn clematis and Japanese Climbing hydrangeas work their way up to blanket the concrete.

Walkways are a bit more difficult to hide being that they still have to be passable, but the extra-wide walks are invaded by junipers and cotoneaster. This softens the hard lines formed by the edge of the concrete.

Concrete drives are the most difficult. Any plant spilling into the drives will certainly be run over. I learned this last year, because every time my sweet potato vine crept over the curb, it would meet up with a car tire. And the tire always got the better of the encounter.  So, I am working overhead to shade the concrete drives. I planted some new oaks along the drive last year. I selected a Chinquapin Oak because of its breadth.  It gets wider than it is tall.  Although I will be long gone before it reaches maturity, I have satisfaction in knowing that the "Hide the Concrete" game will continue!

Posted by Bob Rensel

Growing roses has been called a labor of love. For centuries, poets have written about suffering the thorns in order to enjoy the beauty and fragrance of the rose. Athletes have a more simple saying: “no pain, no gain.”

Let’s face it, roses are far from low maintenance plants. They are susceptible to a variety of insect and fungal problems. An especially cold winter can cause a lot of die-back, and humid or rainy summers bring on the inevitable black spot fungus. Yet, so many gardeners still find a place for this plant somewhere in their yard. Perhaps it is for sentimental reasons. Or maybe it is because the rose has such a long tradition in literature.   For whatever reason, start your roses off this time of year on the right foot with good structural pruning.

Now is the time to prune shrub roses into a nice v-shape. Follow the rules of pruning and first remove any dead, diseased or crossing canes. Then, select the outwardly branching canes that will form the v-shape and remove the other canes. Limb up the canes that remain so there is not a lot of growth low to the ground where fungal diseases can frequently take hold. Make your pruning cuts just above the buds on the cane in order to direct the new growth outward.  A lot of inward or congested branching leads to poor air circulation and potential fungal problems.

Don’t forget to sterilize those pruners as you move from shrub to shrub to prevent the spread of any diseases. I use rubbing alcohol. It also comes in handy when one of the thorns inevitable finds its way into my hand or arm. But, “no pain, no gain.” The reward will be there sometime around the end of May.

Posted by Bob Rensel

My Lenten Rose (Hellebores x hybridus) is finally blooming. Last year, they started blooming the first week of March and kept blooming for a couple months. They even survived the early-April deep freeze that killed the buds on so many other plants. What a tough plant!  But this year they had to sit tight under several inches of snow for much of March. Now that the new growth is shooting up with its pale, spotted flowers, the old growth needs to be removed. 

Hellebores are promoted as being a nice evergreen ground cover. They do provide nice green foliage throughout the winter, but by now, last year’s leaves are looking pretty ratty and need to be removed to make way for the fresh new growth. 

Last year, I learned not to plant my tulip display in front of the Hellebores. They were so show-stopping in March and April that people passing by would walk over the emerging tulips to get a closer look. But unless you clean up the old growth, the dramatic effect of this plant can be lost.

Note, too, that Hellebores are a bit pricy and take a couple years to fill out. But believe me when I say they are well worth the cost and the wait for those of you that crave blooms in March and April. 

Posted by Bob Rensel

My winter planter arrangements looked great in December and January, but by March they are looking a little sad. The broad leaf evergreens such as American holly branches and trailing English ivy are pretty browned out from the winter winds. The red twig dogwood branches held up nicely as have the curly willows. But the cut conifer branches make the container look too much like a December holiday display.  While pansies, violas, snapdragons and stocks are considered cold-hardy annuals, they are not going to perform well in a planter while temperatures are still consistently below freezing. So, what can you do to spice up those winter displays in March and April?

One option would be to fill containers with an early blooming perennial such as Hellebores. These plants tend to be expensive, so I would only consider this if I needed this plant elsewhere. I would pull it from the container in May and plant it in my garden. But last year, my Hellebores bloomed throughout March and April. And since these blossoms tend to droop downward, having them up in a container makes them easier to appreciate.

Another option is to use what is still working (such as the red twig dogwood branches) and replace the parts of the arrangements that are getting old. Since I am cutting back the ornamental grasses right now, some of these stalks can be bundled up and used in a container. For that matter, any interesting or gnarly shaped branches that are pruned away in the spring have potential in a container arrangement.

Lastly, bulbs can add a lot to containers in March and April.  This takes some advance planning. In the fall, when I am planting tulips and daffodils, I make sure there are extras that I pot up and hide away somewhere in the back of the garden. Then in the spring, when the bulbs in the beds start to show, the ones in the pots can be swapped in and out of the containers for matching displays.

If you have any ideas or photos of effective cool-weather container arrangements for March and April, please send them to me so I can try them out.

Posted by Bob Rensel