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Saturday, May 25, 2013

Did you see the results of our latest superflight?

A “superflight” occurs late in some winters. The most recent superflight just finished – the end of winter brought an unusual number of Red-breasted Nuthatches and Pine Siskins into this area. If memory serves me, the superflight prior to that (in north Texas) was 2007, when Red-
Red-breasted Nuthatch
breasted Nuthatches were all over the place.

In the short term, it has to do with the natural food (not from feeders).  If it’s particularly plentiful one year, a superflight could happen. Of course, it affects summer birds too, what with all the leftover natural seed and the resultant abundance of vegetation.

In the long term, this is one way birds expand their natural territory. That is, if birds see that the environment (weather, vegetation, natural food etc.) is good, they might stick around, or visit regularly.


Dining on eggshells       As nesting season kicks into gear, we save eggshells (from breakfast or whatever) for the birds. Birds know that creating an egg (or several) inside a 2-ounce bird-body really saps the calcium from the female bird. Somehow, birds know they need to replace this calcium. So they eat eggshells enthusiastically! We break the shells into pieces no bigger than a fingernail; then heat them to kill any bacteria – 10 minutes at 350 should do it. Then we just set them outside on an old plate.


Wednesday, May 22, 2013

Sensible alternative to trying to grow grass under trees

 As a Landscape Architect, one of the most common concerns I encounter is that lawns do not grow well under trees.  So I’m often asked how to make lawns grow there. 
Invariably, my response is “don’t even try!” Making north Texas lawns grow well within the root zones of trees usually means putting a whole lot of stress on trees, which often results in the tree's premature death (a tree under stress attracts more bugs, too, which can affect other plants as well). Lawns and trees are simply not compatible.

A tree’s roots are spread throughout the soil directly underneath its canopy. Contrary to what we all learned in school, most of these roots are in the top 6-inches of the soil, where the most nutrients are found. So, if a lawn is encouraged to grow in the same area where a tree’s roots are, there’ll be constant struggle between lawn and tree. This may make lawn care people happy (and wealthy) but avoid getting caught in the struggle. There are several reasons why trees and lawns don’t coexist.  


A typical lawn requires a lot of water. A typical tree doesn’t. So if you water the lawn whenever it needs it, the tree’s roots will suffer – and may rot. Also, since it’s shady under a tree, the water will stay there too long - it won’t evaporate as quickly as it does in the sun.

Typical lawns require a lot of fertilizer. Since a high level of fertilization isn’t needed by most trees, they could “overdose” on chemical fertilizer.  Some kinds will even kill them over the years. Even more damaging is the use of “weed and feed” fertilizer, or other chemical fertilizers with a high salt content, which can easily weaken or kill a tree.


Since almost all lawns require sun, and a tree creates shade, a homeowner’s impulse is to remove some of the tree’s leafy branches. But a tree needs every leaf it creates, to grow. If too many branches are removed, the tree’s ability to photosynthesize is lessened, and it suffers.


Disturbing a tree’s roots (even slightly) by tilling, adding soil or adding sod stresses the tree by interfering with its ability to obtain nutrients from the soil through its roots. This is why planting lots of cute little flowers beneath trees is a terrible idea.
Over the years, I’ve found that by far the most successful solution is to plant a ground cover under the drip zone of the tree. Forget about a lawn right there!  The goal is to grow a ground cover in as much of the tree's root zone as possible. Of course, if the tree is a newly-planted “stick”, plan the ground cover bed for the tree’s size in about 10 years.  

 Adding a layer of soil on top of the tree’s roots (putting very heavy stress on the tree), will very likely kill the tree over a period of several years. Instead, carefully plant the ground cover under trees - it's lawn. It's far better for the trees' health.

Some of the most reliable “under-tree” ground covers for north Texas are pigeonberry, vinca major, Virginia creeper, cedar sedge, inland sea oats, liriope, wood fern and horseherb. Among these I often randomly plant some shade-loving flowers (Turk’s cap, columbine, spiderwort etc.) for some seasonal color. Several do a wonderful job of attracting birds and butterflies too.
Match the tree’s preferences for water, fertilizer etc. to whatever you plant beneath it, and you’ll have a healthy, extremely low-maintenance area that’ll be a lot more attractive than half-dead grass, exposed tree roots or bare dirt.


Sunday, May 19, 2013

Why red food coloring is bad for Hummingbirds


Black-chinned Hummingbird
According to Wildbird magazine, if nectar is dyed red, a typical Hummingbird (weighing just a few grams) takes in 10 times the amount of dye necessary to cause DNA damage.

High doses of Red #40 (the most popular coloring agent) will also result in “significantly reduced reproductive success, parental and offspring weight” according to researchers. Plain nectar is what they need.  Nothing more.  Another research study proved that red food coloring is, more often than not, harmful to Hummingbirds - damaging the birds' DNA.


     No study has ever shown that red coloring in nectar attracts them. Adding color to nectar is just an “urban legend”; it’s never been proven to be necessary or helpful.  Nowadays, almost all feeders are colorful enough all by themselves.  In truth, it’s not just red that attracts them.  It’s any bright color except green; (an adaptation that lets them spot nectar-producing flowers in a leafy jungle).


Here in north Texas, microscopic bits of mold (found in most food coloring) can multiply rapidly in heat, ruining an entire batch of nectar and making the birds go elsewhere.





          So please keep the nectar fresh and clear, and the Hummingbirds healthy!


We're fortunate, in north Texas. The Central Flyway passes overhead. This 

Black-headed Grosbeak &
Lazuli Bunting

migration route briefly brings us all sorts of birds that are bound for Canada, upper Midwest, Mississippi valley and so on. In the fall, it brings us birds from those regions, bound for Central and South America.

Each spring and fall we have a good opportunity to see birds native to somewhere else, like these two in the photo. They stop in mid-flight to rest and "gas up" for the next leg of migration. That's IF they spot a safe, vegetated place, and it has the food (seed and insects) they eat, and water to drink and freshen up.

It doesn't matter much how large or small the habitat is - some of the most popular and "bird-friendly" spaces are on lots an eighth of an acre or less.  After all, birds have the entire sky to cavort in, in addition to the ground-level habitat.