This blog has moved

Please visit our new blog at http://www.almstead.com/blog/

Why Do We Prune?

Everyone knows that it’s past time to prune when a large branch drops onto their lawn or car. But many people wonder exactly when a tree first needs to be pruned. When it’s 50 years old? 20? 10?

Think younger.

Pruning serves many purposes – and eliminating dead branches is just one of them. For a young tree, pruning offers the opportunity to correct many of the issues that will cause problems later on – and even lead to an early demise.  One example: co-dominant stems. A co-dominant stem simply means the tree splits into 2 or more vertical stems (trunks). While for some trees, such as birch, multiple stems growing from the base are common and natural, for most trees this is undesirable.

When stems are competing in a tree, there is inherent weakness. In a mature tree, the double trunk may not be strong enough to support the heavy canopy. Tree failure is common in this situation. When we see this developing in a young tree, we have the opportunity to choose one trunk and prune away the other wood, leading to a safer, healthier tree. Even in a mature tree, when it’s too late to eliminate one of the stems, the crown can be reduced to lessen the weight load supported by the weaker stems.

When arborists look at a tree, we look at the “scaffold”: the arrangement of stem and branches. We want to see strong unions between each branch and the stem. Usually, each branch is joined to the trunk through a “branch collar” a ring of strong wood that supports the developing branch. The union between stem and branch should be smooth, like the letter “U.” If branches or stems are too close together, as in the case of a co-dominant stem, this smooth, strong union is unable to form correctly. Instead we see a “V” between the two rivals. This V zone between the stems or branches is vulnerable to splitting (see the picture). With periodic pruning throughout the life of a tree, we can create a strong, balanced scaffold as the tree develops, which leads to a healthier and safer tree.

As trees mature, we want them to grow with a certain symmetry. This isn’t just because it is pleasing to the eye: symmetry means the weight of branches and leaves will be balanced, making the tree more stable. An arborist will also remove branches that are crossing or competing for the same space. This eliminates damage from branches rubbing into each other, and also opens up more space among the branches. This space increases airflow beneath the canopy which creates a less hospitable climate for insects and disease to spread.

Pruning a tree regularly throughout its life will actually reduce problems later on. It’s similar to seeing a dentist: periodic checkups and minor dental work throughout your life are preferable to procrastinating until you need a root canal or lose a tooth.

There are, of course, many other reasons to prune: to keep a tree from impinging on a house or wires, or to open up a view, to name a couple. Although pruning can be done at any time of year, I feel winter is the best time. Winter creates a more sanitary environment (no bugs!), and of course, it’s easier to get a clear view of a tree without its leaves.

 

Here’s an example of a tree with co-dominant stems. The V-shaped attachment makes the tree vulnerable to splitting: the process has already begun, and this tree is at high risk of failure.

Why Are There So Many Grass Seeds?

What we call “lawn grass” covers a variety of plants from several genera. We typically divide lawn grasses into two broad categories: cool-season and warm-season. In our area, cool-season grasses are grown almost exclusively, since our winters are at the limit of tolerance for warm-season grasses. Four species account for almost all of the seed planted in our area: Kentucky bluegrass, perennial ryegrass, tall fescue and fine fescue. The roots of these grasses start growing when temperatures reach about 50 degrees; the shoots start growing quickly when the temperature is in the 60s. As the thermometer reaches 80 degrees, growth slows and the grass becomes dormant in high summer heat.

As you can see from the accompanying table, each variety of grass has different characteristics. The

Source: Cornell University Extension

first important distinction is between sun and shade. Unfortunately, there are few plants that will grow in both full sun and deep shade—including grasses. So if you have a typical lawn (a grassy patch surrounded by trees), you probably have full sun at the center and shade at the edges. This is why sun/shade mixes were developed.

Grass requires sun. When we refer to “shade,” we really mean at least four hours of dappled sun daily. If you get less sun than that, you can sometimes prune your trees to allow more light to reach the grass. If you have deep shade, a groundcover such as pachysandra or mulch is a better choice.

While a sun/shade mix is generally the best choice for the varied conditions of a lawn, you may want to choose a single grass to meet the conditions of a specific area. When you’re filling in patches in the shade, you could use fine fescue alone or a shade mix. Similarly, a sunny spot will do well with Kentucky bluegrass or almost any mix.

Sometimes sun vs. shade is not the only consideration. If you have kids frequently playing on the lawn, rugged quick-growing tall fescue may be a better choice. This is also a good choice for a slope, and has the benefit of better drought tolerance. However, because tall fescue is a coarser grass, it doesn’t have the silky appearance that a fine grass has. If you want a strong, low-maintenance lawn, a blend of 65 percent tall fescue (combined with 15 percent perennial ryegrass and 20 percent Kentucky bluegrasses or something similar) is a good choice.

The grass that we grow for our lawns was originally brought from Europe along with the animals that like to eat it; these grasses quickly replaced our native grasses. As many of us have become more interested in native plants, there has been renewed interest in buffalo grass, which originally covered the Great Plains. Buffalo grass is a warm-season grass, but can be grown in our area. Except for seedheads, it stops growing at 4 to 6 inches, so it requires little mowing. There are some problems in planting buffalo grass, however: it requires full sun. It is also killed by traditional lawn weed controls; hand weeding is usually necessary.

Planning for a Beautiful Lawn (Part 4)

Pest and disease control

Over the last few weeks, my blogs have covered several aspects of caring for your lawn. I’ve discussed the importance of core aeration, compost and mowing; fertilization and weed control.

The healthier your lawn is, the more likely it is to resist pests and diseases. Some pests, however, can be hard to avoid—particularly white grubs. Grubs are the larvae of beetles (primarily Japanese beetles and masked chafers) that develop in the ground. When the population of grubs is significant, you will start seeing brown patches in your lawn, particularly toward late summer. To make matters worse, grubs are a delicacy for some animals, such as skunks and raccoons. Sometimes the problem goes unnoticed until you see holes dug in your turf one morning. Grubs like sunny areas with moisture, and are not often found in shade or in dry lawns.

If you see brown patches in your turf, you can lift up a piece of turf where the brown patch meets green lawn and look at the roots to check. The grubs are white and C-shaped. It only takes about 10 grubs per square foot of lawn to cause visible damage.

If you catch the problem early, or if you see a large adult population of beetles,  Almstead lawn technicians usually perform a summer lawn treatment.  Although mid-summer and fall treatments are sometimes effective, June is the best time to prevent grubs from damaging your lawn.

There is also an effective organic treatment for grubs which we use, which utilizes milky spore, a grub-killing bacterial powder. However, this only works on Japanese Beetle grubs and must build up in your soil over time to work. We can test your lawn to identify what type of grub is living there.

Other insects, such as chinchbugs, can be damaging to lawns. When you see yellowing patches, or grass blades that have been notched and nibbled, we try to identify the insect responsible and narrowly target it with the appropriate control.

Lawn diseases are usually fungal. Fortunately, they are not common. Unfortunately, they can be difficult to diagnose and can spread quickly. If you suspect your lawn is suffering from disease rather than insect damage, it's wise to have a sample taken and analyzed in order to determine the right treatment.

The best prevention for lawn disease and pests is maintaining the health of the lawn. A well-nourished, watered, well-mown lawn becomes a self-sustaining system that is hostile to predators.

- Ken Almstead, arborist and CEO

Planning for a Beautiful Lawn (Part 3)

Weed control

Over the last two weeks, my blog has covered the basics of preparing your lawn in spring and how and when and how to fertilize it. This week, I’ll talk about weed control. The next blog will cover pest and disease control.

There is no universal definition of a weed. You may be content to see clover among the grass stalks in your lawn, while someone else reaches for the Roundup. Some people carefully scrutinize their lawns and remove any undesirables with tweezers while others are content as long as the weeds are green. Is it enough to eliminate the crabgrass and broadleaf weeds and leave some clover mixed in your lawn? Or do you want a lawn as luxuriant as a golf course green?

Frankly, having a completely weed-free lawn is setting the bar rather high, and will require frequent application of weed control products. Since most herbicides are synthetic, a totally weed-free lawn is not compatible with an organic-only care philosophy. 

There are two major categories of weed control: pre-emergent and post-emergent. The pre-emergent treatments prevent seeds from germinating. This helps control weeds like crabgrass, which begin from seed each year. There are several kinds of synthetic pre-emergent products available. Pre-emergent herbicides won’t do much to get rid of plants like dandelions that overwinter in your lawn and spread through roots.

Post-emergent herbicides target broadleaf weeds, such as dandelions, plantain and ground-ivy.  Some can be applied to the entire lawn; others are made to squirt directly onto the offending weed.  The herbicide will be absorbed into the weed and kill it off, roots and all. Be careful – it will kill anything it touches with leaves, including your annuals and perennials.  

There are no comparable herbicides in organic care. Ideally, as you create a healthier environment for grass, it will become harder for weeds to compete. Weeds tend to thrive and out-compete grass in compacted soil—which is why annual core aeration is a good technique. There are organic vinegar-based  spot-herbicides that can be sprayed on weeds—but they can kill grass as well, if you’re not careful. Perhaps the best organic practice is to pull weeds by hand. There are several hand tools designed to remove weeds; just make sure you extract the entire root or the weed will grow back.

How often you apply weed controls depends upon your philosophy and your budget. Although pre-emergent controls are usually applied in early spring, the post-emergent controls can be applied as you notice the weeds appearing. You can just use them in the areas where weeds are apparent. They are usually applied when the lawn is dry; they need a few hours free of rain or watering. When Almstead provides lawn care to our clients, we typically offer two applications of pre-emergent herbicide in spring, and then follow up with monthly inspections, applying post-emergent controls as necessary.

Hand-pulling weeds is usually easiest when the ground is moist. If you intend to compost the weeds, make sure you turn your compost pile often and that it gets warm enough to kill the seeds (over 131 degrees). Otherwise, you’ll wind up cultivating them rather than killing them.

Planning for a Beautiful Lawn (Part 2)

Last week, my blog covered the basics of preparing your lawn in spring and how to mow it. This week, I’ll discuss fertilization. The next blog will cover weed control, and finally pest and disease

control.

How you nourish your lawn depends a lot upon your “turf philosophy.” A wide range of choices is available, from totally organic to traditional synthetic products—and combinations in between.

Whatever your philosophy on type of care, it’s useful to begin by having your soil tested. The cost is nominal and it’s easy to do: There are both mail-in and drop-off labs you can use. Cornell University Extension in Valhalla will do pH testing, and they can also direct you to a source for more extensive testing (914-285-4620). Once you have a soil analysis, you can fertilize with the products that are right for your property.

In fertilizing lawns, less is often more. I see too many people (sometimes including landscapers, unfortunately) dumping large amounts of products on lawns, without understanding what the turf actually needs and can absorb. The goal is to create a healthy lawn ecosystem, which will ultimately lead to less use of soil amendments. (See my last blog about the value of core aeration and composting.) When you add too much of some synthetic fertilizers, it will either wash through the soil unused or actually damage the turf by “burning” the grass.

One of the advantages of organic products is that they are far less likely to damage turf. Organic fertilizers break down slowly and gradually release their nutrients to improve the structure of the soil. This means that it will take longer to see results from organic products; the soil improvements from organic fertilizers will ultimately lead to improved turf, but it could take a couple of seasons. In order to expedite this process, some organic lawn care specialists (including my company, Almstead), “brew” Compost Teas that contains live beneficial microorganisms. This liquid compost can be used to add these organisms directly to the soil, offering a boost to the organic soil improvement process.

One of the questions I’m often asked is, “How much and how often should I fertilize?” This depends on your lawn goals, available time (assuming you’re doing it yourself) and budget. In general, 2 pounds of nitrogen is the right amount for per 1,000 square feet of lawn in our area, but soil testing may modify that proportion for your property. The rule of thumb for timing is to fertilize around Memorial Day and Labor Day—and that’s not a bad plan. We have many clients who are happy with the results of a twice-per-year fertilization program. On the other hand, more frequent fertilization visits allow us to narrowly target the growing cycle of the lawn and tailor nutrition to weather and conditions. So we also offer a six times/year schedule (organic, traditional or mixed). That level of attention usually leads to a lawn that looks lush, plush and close to perfect.

Patience and consistency are important in developing beautiful turf: your lawn won’t go from scrub to velvet in a single season. Consistent care, including proper mowing and watering, will help your lawn look great. Next week, I’ll discuss another important issue: controlling weeds.

Planning for a Beautiful Lawn: Prepping and Mowing

Having a beautiful lawn requires attention. Over the next few weeks, our blog will cover a few of the most important dynamics of creating lush, green turf.  I’ll begin with lawn prepping and mowing.  In the next few weeks, I’ll cover fertilization, weed control and pest/disease control.

Creating a healthy lawn is a process that starts with choosing the right grass seed for your location. The first thing to understand is: grass doesn’t grow in the shade. While some grass is more tolerant of shade than others, it will still need several hours of dappled sunlight in order to look good.  Often it’s possible to thin out trees to permit enough light to reach the lawn. If the area is permanently in shade, you might want to forget about planting grass there, in favor of ground cover, hardscape or mulch.

Several varieties of grass are commonly planted in our area; each has its own strengths and drawbacks. There is no “right” grass for all lawns. The right grass for you depends on your soil, sunlight and priorities: do you want a lawn that stays green into fall? Or grass that can take a beating from active play? Or a lawn that can survive with less water?

Kentucky Bluegrass is popular and durable but doesn't like shade. Fescue and perennial ryegrass are also common in our area, and are more shade tolerant. Most lawns are planted with a mix of these grasses, and different grasses will dominate different areas of your lawn. Follow this link to Cornell Cooperative Extension for more information on grass types.  

It’s often useful to begin your lawn program by checking for soil compaction. Try inserting a long screwdriver into the turf. If it doesn’t easily go in 6” deep, the soil is too compacted to encourage your grass to grow. You’ll want to use a core aerator to pull plugs from the soil and stimulate the roots to grow. This will also help to avoid thatch buildup. If you don’t use a professional for this task, rent or borrow an aerator: the spike shoes and hand tools you see advertised really don’t do the job.This is typically a fall activity, because the plugs may contain weed seed that you don't want to encourage to grow. 

Top dressing with a thin layer of compost in the spring will also get your lawn off to a good start. (This can also be done in fall.) Overseeding can help fill in bare patches. 

One of the most important parts of lawn care is mowing. Proper mowing actually encourages your lawn to grow thicker and stronger, by channeling the growth energy into the roots. We recommend setting your lawnmower at 3” – 4”. Maintaining a lawn at less than that makes the lawn very vulnerable to drying out and scorching.

Many people are using mulching mowers now, too, which distribute the grass cuttings back into the lawn, where they decompose, releasing their nutrients back to the soil. Most experts recommend mowing about 1/3 of the length of the blade every time you mow. For mulching mowers, this will keep the cuttings short enough to sink back into the lawn.