Clematis ‘Barbara Harrington’

Over the years of dealing with the gardening public, I realized that we often throw around terms and names that could be a bit misleading. Eventually, I jotted some of these tricky terms down and came up with the following:

The mountain ash tree (Sorbus) may come from the mountains but it is not really an ash tree (Fraxinus). It is actually a member of the Rose Family and is a close relative to apples, pears and roses. Mountain ash trees are not bothered by the Emerald ash borer either although, since mountain ash have their own serious disease and insect problems, that might not be a bad thing.

Boxelder tree seedlings are often mistaken for poison ivy when they first emerge from the seeds. They have the same three leaf structure but they soon form a tree-like stem and not a vine like poison ivy.

Douglas fir is not a true fir tree. Kirk Douglas was the star of Sparticus.

Blackberry plants are less winter hardy than raspberries. When you pick a blackberry, the little white pit comes along with it while the pit stays on the plant when you pick a raspberry.

Dutch elm disease killed primarily American elms (Ulmus americana). It might have come to the U.S. from Holland, thus the name.

Oregon grape holly (Mahonia) is not a holly (Ilex). It may be from Oregon but it does not produce grapes either.

The roots of black walnut trees (Juglans nigra) produce a substance called juglone that is poisonous to many other plants. Tomato plants growing near walnut trees will often wilt and die in late July.

Hostas used to be called Funkia. There was a rock group called the Funkadelics back in the 1960s but I don’t think they had anything to do with hostas but might have been familiar with grass

All azaleas are actually rhododendrons. Only a small number of rhododendrons are azaleas.

Spider mites are not insects. Insects have six legs. Spiders and their relatives have eight. Eight is Enough was a television program back in the 70’s.

Staghorn sumac has red berries borne at the tips of the branch. Poison sumac has white berries borne along the stem. Chuck Berry is one of my favorite singers.

Grape hyacinth are not hyacinths. They are in the genus Muscari. Their fruit makes lousy wine.

Onions form bulbs in response to day length. Some that will grow in the North will not form bulbs in the South where day length in the summer is shorter.

Bats have their young during the first two weeks of June. The runt of the litter is always named Robin.

Yellowjackets, wasps and hornets live and use their nest just one year. A few queens survive the winter and re-establish completely new nests the following spring. The rock band, “Queen” maintains a nest in England.

As always, if you have landscape gardening questions or have a topic you would like to see covered, please let me know.

Also, I have recently published a couple of eBooks that you might want to check out. The titles are, “A Rookie’s Guide to Designing Beds and Borders” and “A Rookie’s Guide to Implementing Beds and Borders“.

I am currently working on the next eBook, “A Rookie’s Guide to Hostas, Hostas, Hostas” which should be ready by the end of November, 2012.

When a tree is under stress, most people notice the above the ground symptoms first and blame them on insects or diseases. It is easy to see wilting leaves, dying branches and loss of vigor. However when a large, established tree begins to slowly die over several years, the cause may lie hidden in the ground. The symptoms may arise from a much misunderstood area called the root zone.

Roots serve several purposes in the life of a plant. They help to anchor the plant in the soil so it does not fall over. Roots also act as a storage locker for sugars and carbohydrates to help trees survive the winter. Their most important role is in the absorption of water and the nutrients dissolved in that water.

Some people believe that the root zone of a tree is a mirror image of its canopy. If the tree is 40 feet tall and 30 feet wide, then the root system must have the same dimensions. In reality, the vast majority of tree roots are located in the top 18 to 24 inches of soil. This is only logical since that is where the water and nutrients are located.

Sassafras, walnut, some oaks  and a few other species form a true taproot which makes them difficult to transplant. They send thick anchoring roots deep into the ground but these constitute only a minor percentage of the total root system. Most trees do not form a true taproot.

Another commonly held myth is that the roots of a tree spread outward only to edge of the drip line. This is the outer edge of the canopy where water drips off the leaves. Although it varies by species, most trees have roots that grow way past the drip line. A few species actually send roots hundreds of feet away from the main trunk in all directions.

Understanding the extent and shape of a tree’s root system can be helpful in maintaining its health. The root system must be in “balance” with the canopy so that enough water and nutrients are delivered to support the leaves and stems. Damage to the root system will result in a loss of leaves, branches or, in severe cases, the entire tree. Conversely, loss of branches will result in a corresponding loss of roots.

Roots may be damaged in many ways. Soil excavation or rolling heavy equipment over the root zone is an obvious problem. Covering the roots with cement or piling a thick layer of additional soil over them is harmful too. Discharging water softener backwash, swimming pool chlorine or other chemicals on the soil over the roots may prove fatal. Excessive application or spillage of herbicides and fertilizers will also wreak havoc on roots below.

Damage may also occur in less dramatic ways. Thirty years of foot traffic and rain pounding on the soil may cause soil compaction. Compaction is perhaps the key nemesis of old landscape trees. When the soil becomes compacted, there is no room for oxygen. Roots must have oxygen in order to grow and do their jobs properly.

Planting a tree too close to houses, sidewalks, driveways or other obstructions will also limit the expansion of the root zone. As the tree grows, it needs more roots and such restrictions can cause serious problems in later years.

The key is to be aware of the potential damage that any activity may have on the root zone of a tree. Tiny root hairs are most responsible for water and nutrient absorption. They are also the first to be destroyed when the root zone is bothered.

Identification

The best way to identify poison ivy (Toxicodendron radicans) is by its characteristic compound leaf consisting of three leaflets. There is a lot of truth to the old saying, “Leaves of three, let it be.” The leaflets are each two to four inches long, dull or glossy green with pointed tips. The middle leaflet is generally larger than the two laterals. The margins of the leaflets are variable, appearing irregularly toothed, lobed, or smooth. The leaves are positioned alternately on the stems.

In contrast, Virginia Creeper (Parthenocissus quinquefolia), a non-poisonous vine often mistaken for poison ivy, has five leaflets radiating from one point of attachment. I use a slight variation on the poison ivy saying, “Leaves of five, let it thrive.”

Poison ivy can be found in one of three forms; as an erect woody shrub, a trailing shrub running along the ground, or a woody vine. The vine is usually seen growing on trees or other objects for support. It has aerial roots along the stem that give it the appearance of a “fuzzy rope.”

Yellowish-green flowers occur in compact clusters in leaf axil, and are produced in June or July. These are followed by a waxy, berry-like fruit which is grayish-white and have distinctive lines marking the outer surface. They are about three-sixteenths of an inch in diameter.

Poison ivy is “poisonous” all year around. The oil in the leaves, stems, roots and fruit are what cause the skin irritation. Actually, the rash is an allergic reaction. As I understand it, the allergy may be developed at any point in your life. For instance, you might get by handling poison ivy for decades and the, all of a sudden, develop the allergy and become infected. Therefore, regardless of your history, care should always be taken when working in or near poison ivy.

Although direct contact with the plant is the common method of transfer, handling clothing, tools, objects or animals that have become contaminated with the oil may also result in spreading the problem to people. I once had a lady tell me that her husband had shot a rabbit and it had come to rest in a patch of poison ivy. She wondered if she was safe in touching the rabbit since she was very susceptible. Sounded as if she would be taking a big risk in preparing the rabbit for the dinner table.

Control

There are at least three approaches that can be effective in eradicating poison ivy in ornamental beds. They include hand pulling or grubbing out; severing the vine near ground level and then treating the cut stem and regrowth with an herbicide; or applying an appropriate herbicide to the leaves of individual poison ivy plants.

Hand pulling should not be done by people who are sensitive to poison ivy, of course. Even if you seem to immune, always use heavy rubber gloves. This method is most successful when the soil is moist. The roots can be dug and pulled out in long pieces. Care should be taken to remove the entire root because the plant can re-sprout from sections of root left in the ground. One method of disposing of the plant material that has been dug out is to bury it in a hole several feet beneath the surface of the soil. Do not just put it into a plastic bag for the garbage man who might not like being exposed to poison ivy any more than you.

Avoid skin contact by wearing gloves while you work and washing clothing and gloves immediately after. The washing machine should be rinsed thoroughly afterward to eliminate the possibility of contaminating other clothing. Also remember that oil may be on the glove so care must be taken in disposing of them too. All in all, this is a difficult option for removal of poison ivy.

Vines growing on trees can be difficult to pull out of the ground because their roots may be entangled with the tree’s roots. Again, wearing rubber gloves, cut the vine at the base and carefully pull it out of the tree. An herbicide specifically labeled for poison ivy control can be applied to the new shoots that will soon emerge from the base of the old plant. Herbicides are most effective if applied to actively growing foliage of young vines two weeks on either side of full bloom, in early summer.

Even herbicides labeled for poison ivy will rarely provide complete control from a single application. Poison ivy is a vigorous plant so repeat applications over an entire season may be needed as new growth appears. Be sure to read the label to ensure that poison ivy is listed on the label, then follow the manufacturer’s directions.

Fortunately, poison ivy is not a big fan of cultivation. It is generally found in areas where the soil has not been disturbed recently. Often if it is found in a flower bed or border, it is creeping in from surrounding areas.

When flowers begin to drop their petals, it is a signal that the plant is ready to set seed and, generally, to stop producing blooms. In nature, that is just fine since the primary goal of the plant is to produce seed to guarantee another generation and continuation of the species. However, in our gardens, we just want the plants to persist in producing flowers for as long as possible.

To keep the plants going, we gardeners have developed a technique called deadheading which will help us achieve our goal. It is not a very complicated procedure,  just keep an eye on your plants and, when the blossoms begin to fade, gently snip them off. This will accomplish several things. First, it will trick the plant into “thinking” that it has not achieved its goal of seed production. Therefore, with stubborn persistence, it will usually develop more flowers for us to enjoy.

The other thing that deadheading accomplishes is that it prevents seed production. Many of the plants we grow in our gardens are hybrids. They are the result of cross-pollination which combines the genetic material from two different plants. When this is done under the trained eye of the plant hybridizer, the results are predictable for the plants or seeds we buy from the nursery. The next generation exhibits hybrid vigor and produces an outstanding set of flowers.

Unfortunately, if you save the seed from these plants or if they just fall to the ground in your garden, the results are not predicable. Some of the seeds from hybrids will “revert” to the parental types and produce plants that you may not recognize. This can be fun if you are experimenting and trying to find new varieties. But, if you want a homogeneous group of white flowered garden phlox from their seed, you will probably be disappointed.  For example, named cultivars of garden phlox, Phlox paniculata, will often revert to common pinkish flowered wild types when seed is collected from a hybrid.

Deadheading your annuals i.e. bedding plants, is pretty straightforward. It will help to keep producing flowers into the cold of autumn. The goal with annuals is to keep them blooming and blooming from the time you put them in the ground in the spring until they are killed by the frost in the fall. Some of the new cultivar on the market have been chosen to keep flowering even without deadheading. The “Wave” petunias are an example of this advance. Unfortunately, many, many other annuals are not to this stage of development and still benefit from deadheading.

With perennials, it can be a little more complicated. Perennials are plants that live more than two years. Some of them like peonies, daylilies and hostas live for decades and decades. Deadheading these plants is meant to “clean them up” and to avoid letting them go to seed. In some cases, it will encourage some additional bloom but most perennials will limit themselves to their normal blooming season length even if you dead head them. A few will put out some additional blooms but they will not react like annuals.

A small group of perennials are called “short-lived” since individual plants may only live 4 or 5 years. Coreopsis, gaillardia, delphinium, primulas and similar plants do not have nearly the longevity of hostas or daylilies. In these cases, you may not want to deadhead them and allow them to self-seed.

By knowing your plants and understanding which ones come true from the seed, you can save yourself some money. Primroses are an example of a species that seems to reproduce pretty well from seed. Let them spawn seedlings and you won’t have to go to the store and buy more every few years.

Finally, we come to the case of deadheading roses. There are many different types of roses that are currently grown in the home garden. The vast majority of people only think of hybrid tea roses which are the ones you buy at the florist.

It is important to periodically deadhead hybrid tea roses (an some of the other types too) throughout the season. If they are allowed to form seed heads i.e. rose hips, they will stop flowering. So, once the flower begins to “shatter” which means that the petals begin to fall, it is time to deadhead that cane. Cut the cane down to the next 5 leaflet leaf. Snip the cane just a little above that leaf and a bud will form where the leaf stem enters the cane. From this a new little stem will form with a flower bud on the top.

Keep up this process throughout the summer to keep the hybrid tea in continuous bloom. Generally, in northern climates, it is good to stop deadheading roses around the first of August. Encouraging tender, new growth into the fall will not be beneficial to the plant since it will be zapped by frost.  Of course, this rule does not apply to annuals which will be dead with the first heavy frost anyway.

Fertilizing a plant is not the same as feeding a pig or a cat or ourselves. Animals take in carbohydrates, proteins and sugars and during digestion, break them back down into their component parts. The body then uses these elements to build muscle, organs and other tissues. The energy that is released in this process came originally from the sun…through plants. Remember that the steak you are eating came from a cow that ate plants. That fish may have been a predator that ate other fish but somewhere down the food chain, it began with something that was a vegetarian.

On the other hand, plants take the basic elements such as carbon, hydrogen, oxygen, nitrogen, potassium, phosphorus and others directly into their systems. Most of the elements come in through the roots while others enter in gaseous form through the stomata. These nutrients are combined with water, carbon dioxide and the energy from light in the presence of the green pigment, chlorophyll to produce complex compounds such as sugars and carbohydrates. This is the process called photosynthesis that we all learned about in science class.

In the darkness of night, most plants take the carbohydrates and sugars and break them down again. This process is called respiration. The plant uses the end products plus some oxygen to build complex tissues such as roots, stems, leaves, flowers, bark, seeds and other plant parts.

The practical implication of all this bears on how and why we apply fertilizers. The key is to remember that an application of nitrogen will do absolutely no good unless the plant has the proper mix of nutrients, water, light, temperature and chlorophyll necessary to complete photosynthesis.

If I eat a bunch of donuts, cokes and potato chips all the time, I will gain weight no matter how much time I spend in the sun. A plant will not grow unless it has the proper balance of all of those factors needed for photosynthesis. The minimum levels of each input required, however, will vary from genus to genus of plant. That is why some plants can grow in the shade while others require full sun all day long.

Sometimes people think that poor growth in plants can be overcome simply by giving them a shot of fertilizer. They want to fertilize full-sun turfgrass situated in the deep shade to make it grow better. Without adequate light, the plant will not be able to use the nitrogen no matter how much is applied. That is why it is often recommended to fertilize grass in the shade only during the spring or the fall before or after the leaves have dropped from the tree and the grass can receive full sun. Even then, this is a case of trying to make the most of a bad situation.