Shadow Analysis in SketchUp

Performing a Sun/Shadow Analysis can be incredibly helpful during the design process. It's helpful to architects who want to assess solar input to a building for passive or active solar collection. For landscape architects, it has always been ingrained in the materials of our field.

The sun gives life to our plants, the building blocks of our trade, along with the soil and water they bed in. The sun-shadow cycle is to plants as the blankets-on/blankets-off cycle is to people, it determines their waking hours and resting hours.

Sunlight has other effects on plants as well; it's what dries the morning dew. By removing moisture, the sunlight can prevent certain plant diseases, while an increase in shade or quantity of water will make plants more susceptible to plants diseases and fungal infections that thrive in moist environments.

My sun-shadow study had surprising results for me. I learned that the White Pine on the south-west corner of our lot casts more shade than I suspected on our largest garden bed. By using the date and time functions in SketchUp, I was able to see at what time of day our garden bed is in the shadow of the White Pine. This set of images shows the shadows in our yard from the very beginning of our growing season to the end.

If the sunniest hours of the day are from 12-noon to 4pm, this garden bed is progressively covered by the White Pine during these hours. Removing it could increase access to sunlight by several hours each day. I have been hesitant to remove the White Pine for reasons of cost and privacy however, this analysis has proved to be a strong argument for 'repurposing' our pine wood!

The Undead of Winter: Tree Pruning

Chicago Winters are the time of dormancy for plants. For gardeners and landscapers, it is a time to rest and plan. But if you have fruit trees, the dead of Winter is the ideal time to prune.

You will want to wait to prune until after the trees are fully dormant, which can be as early as late January or as late as March. Definitely, prune before the buds begin to swell in the Spring.

Winter pruning is ideal because it reduces the risk of infection. Come Spring, when plant pests and diseases are active, your Winter cuts will be sufficiently healed.

Water Sprouts:
Our trees don't have a problem with Suckers or Whorls, but they make up for it with Water Sprouts. All three of these are undesirable types of growth that will not improve fruit production. Why have fruit trees if you don't intend to harvest some nice fruit, eh? In the above image, I am removing one of many of these thin upright branches growing near the central trunk of the tree.

Air Circulation:
This image sequence shows you Before, During, and After shots when pruning the Water Sprouts from our Apple Tree. Compare them to see how much we were able to open up the core area of the tree. For trees to be able to produce healthy fruit, they need good air circulation.

I was told by a friend to approach tree pruning with the goal to allow birds to fly through the core and canopy. With that, it's important when pruning in the Winter to keep in mind how the tree will look in Spring after the leaves emerge and take up more space.

Harvest, and Safety:
We learned last Summer that, if we were going to make it easier on ourselves to care for fruit trees, it was time to take a No-Holds-Barred approach to pruning. As I said before, since we're growing these trees for their fruit, then I intend to harvest the entire tree (with a small donation to the wildlife in my yard). As you can see in the above sequence, we sawed off a large branch that was (1.) completely out of reach for harvesting and (2). careening rather dangerously over the public alley.

Fruit Tree Pests:
Another major change to our fruit tree care this year will be education and action against the pests that make our harvest and fruit consumption cumbersome. In the past, I've done my best to keep even one day ahead of the insects that have such an amorous affection for our trees. Here's what I learned so far:

I suspect we have one or both of two common larvae tunneling through our fruit. 

Apple Maggots:
What you see: worms
Tree: Apples and Cherries
What to do: hang a Sticky Trap (a red ball or yellow triangle) in Late June through harvest. 2 traps per tree. Remove any fallen fruit immediately.

Codling Moth:
What you see: tunnels
Tree: Apples
What to do: spray Dormant Oil on leaves prior to leaf budding in late Winter or early Spring.

I'm also learning how to use Horticulture Oil, and nylon footies (yes, the kind you use at the shoe store) to protect fruit.

Good Sources for More Information:
Chicago Botanic Garden: monthly gardening checklist
North Carolina Cooperative Extension Service: not our climate but they have Excellent illustrations of fruit tree training and pruning techniques.