Those of us who live in the temperate zones i.e. those that routinely get at least one killing frost, often have to deal with injury to our landscape plants from cold temperatures. When we venture out into the garden in the early spring, we begin to see dead or damaged plants that seemed to be in good shape the previous fall. What happened?
Of course, the first thing and for some people, the only factor we think about is cold temperatures. However, there are several other weather related impacts that need to be considered.
1. Low Temperature Injury – Most gardeners are familiar with the USDA Hardiness Zone map. This divides each area of the country into units based on the typical lowest temperatures expected. For instance, if you are in USDA Zone 5, you can expect to experience winter low temperatures between -10 and -20 degrees Fahrenheit. Continue reading →
Last week, we talked about the types of injuries and damage sustained by landscape plants in the temperate zones. We looked at the effects of temperatures, drying winds, de-icing salt, rodents, clay soils, etc. Now here are a few methods for avoiding this type of damage in your landscape.
1. Low Temperature Injury – The key to avoiding this problem is to not “stretch the zone” with your plants. This means that, for instance, if you are in USDA Hardiness Zone 6, avoid using plants that are only hardy to Zone 7 or 8. You may get away with this for several years if the winters are warmer than average. However, all that it takes is one night below the “typical” low temperature for your zone and the plant may die. That is a fallacy of people when they think that global warming automatically changes their climate zone. You may, in fact, experience above average temperatures for 364 nights but, if that one night in the dead of winter drops below the hardiness level of the plant…it will still be dead.
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.
The mountain ash (Sorbus species) may come from the mountain but it is not really an ash tree (Fraxinus species). It is actually a close relative the apples (Malus), pears (Pyrus) and roses (Rosa) since it is a member of the Rose Family (Rosaceae). Therefore, it is susceptible to many of the same diseases of its relatives including the fungal leaf disease, apple scab and the more serious bacterial disease, fireblight. The better news is, that since it is not a true ash, it does not get attacked by the Emerald ash borer which is in the process of killing millions and millions of ash trees throughout the Midwest.
Crabapple trees (Malus species) can add beauty and interest to the landscape. They can also be messy, sickly and bothersome if care is not taken to select proper cultivars i.e. named varieties, to plant.
There are literally hundreds, perhaps thousands, of cultivars of crabapples currently available. Every nursery or plant store will offer many from which to choose. So, how do you make the right choice for your landscape? The following traits should be considered when purchasing one for your yard: Continue reading →
Many pine (Pinus species) trees in the landscape and along the road may be looking pretty sick this time of year. Their needles are turning brown and, at times, some larger branches are dieing. In a few cases, an entire tree may suddenly turn brown and die in less than a month. What is going on?
Much of the damage is a result of winter weather. Cold, dry winter winds in combination with dry soil will cause pine and other evergreen needles to lose water but they were unable to replenish the moisture from the frozen soil. This will cause needles to turn uniformly brown from top to bottom. Severely affected needles will drop off and some twigs or branches may also die. For the most part, however, trees should survive and will green up again over the coming year or so.
If a plant dies within the first year or two after being transplanted, the cause is almost always “transplant shock.” It would be extremely unusual for an insect or disease to cause an otherwise healthy transplant to die that quickly. So, the question becomes, “What is transplant shock and how do I prevent it from killing my plants?”
Roots, of course, are the lifeline of the plant. They transport water and nutrients up to the leaves as part of the photosynthesis process. Without these inputs, the plant cannot produce its own food and energy supply. Plants establish a natural balance between the size of the root system and the size of the above ground part of the plant. This assures the proper flow of water and nutrients up to the leaves. If stems are cut off, part of the root system dies back. If some of the root system is removed, parts stems and leaves will suffer damage or death.
Hydrangeas are beautiful plants for the home landscape. They come in a wide range of types from flowering shrubs to tree types to large sized vines. Although they are perfectly hardy to many northern climate zones, there are times when they do not bloom. New plants often come from the nursery crammed full of blooms. Then, the following spring or summer…nothing. What is the problem?
Well, the first thing to determine is the type of hydrangea being considered. Different hydrangeas have different flowering cycles and requirements. So, you need to know your plant.
When trees grow tall and begin to tower over houses, garages and driveways, people often become concerned about whether they are a potential danger. Actually, there are a lot of situations when they should be concerned but are unaware of the possibilities. We have all seen the damage that a huge tree limb can cause when it comes down in a storm. Occasionally, people are injured or killed in such situations. How can we tell when a tree is going to come down?
Wow! Another year has spun by and we are heading into 2013. The older I get, the faster the planet seems to spin. Anyone else feel that way? It is always important to take a look into the future this time of year and make some more resolutions (which we can look back on next year and wonder why we did not do any them).
In 2013, I (or we) resolve:
- To always remember that gardening is supposed to be fun. When it becomes a chore, I will figure out why and make a change in the way I do things. I will slow down this year and take it easy in my garden for once. I spend too much time working in it and not enough time just enjoying it. Continue reading →