Garden Guy: When you begin, think of the end


Driving around town, I often see newly planted yards. Even though certain trees such as podocarpus, can grow more than 40 feet tall with a spread of 30-40 feet or more, yet sometimes they are planted 3 or 4 feet apart. Knowing the ultimate height and spread of the tree will help to determine how close to plant the young trees. This is also true for other ornamental plantings and even vegetables.

Podocarpus trees are often planted for a hedge row. The advantage to planting them close together is that they will create the hedge quickly. Planting trees so close together, however, presents some disadvantages.

If 100 feet of hedge is desired, 20 trees are required at a 5-foot planting, whereas 33 trees are needed if planted 3 feet apart. That’s about 60 percent more trees to buy, holes to dig, soil to amend, stakes to buy, etc. Years later when the trees are pruned and topped, the cost may be higher with a denser planting.

The same is true for planting other ornamentals such as hibiscus. There are numerous varieties of this shrub. Many will have a spread of 8-14 feet. Having knowledge of their eventual spread will help in determining how far apart to plant them.

Sometimes two species of trees or shrubs are intermingled. Know the eventual size of each plant and their vigor. Again, planting close together will quickly produce a nice row or hedge, but the more vigorous species will dominate and completely over grow the other.

This principle is also true for vegetables. Some grow quite large and spreading, such as kabocha squash, tomatoes, corn and Portuguese kale. Others remain rather small like lettuce, carrots, beets and radish. When planting, visualize what the mature plant will look like.

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I have a 2-year-old Kadota fig tree that has been producing small inedible figs. I have been told to be patient and that the tree is still immature. But as the tree “matures,” it is getting taller with spindlier branches that have fewer and smaller leaves. Is there some sort of pruning regimen for these to maybe increase the girth of the main trunk and branches? Right now the tree looks like a gangly, thin giraffe. The tree gets fertilizer every two to three months and compost occasionally. Thanks for any suggestions. — Dean

One symptom of spindly growth in plants is sunlight deficiency. Figs need at least eight hours of sun per day. A lack of sufficient sunlight could also explain small non maturing figs. On the other hand, small fruit and leaves, along with poor growth, l leaves could also be a symptom of nematodes or root rotting fungi.

If sun is the problem, move the tree now, it’s not going to get any better. The root rot condition will generally get worse under conditions of high rainfall and poor drainage. Nematodes are difficult to control. Suppression can occur with heavy mulching over the years.

If any or all of the situations above are eliminated or taken care of, you can now worry about pruning. In general, pruning tall, lanky growth should stimulate side buds and thus create more bushy growth.

Figs trees, however, require little pruning, just enough to keep their growth within bounds and to keep the crown open to sunlight and air. Pruning should be done annually during the first few growing seasons in order to establish desired shape. In subsequent years prune only to stimulate new growth or to control size.

Heavy pruning will result in lighter crops the following season. It is best to prune immediately after the main crop is harvested.

Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years. Email your questions to Sakovich at askthegardenguy@earthlink.net. Also, visit his website at www.gardenguyhawaii.com.

 

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