Miscalculating


One of the most common gardening mistakes is miscalculating size and then mislocating based on this miscalculation. It seems almost no one knows or want to learn that all woody plants (shrubs, trees and ligneous vines) have indeterminate growth; i.e., they do not stop growing unless dormant or until they are dead. When I advise people about this during a garden assessment or a group talk many of them seem to simply tune out since it is NOT what they want to hear--an inconvenient truth. They have it in their heads that trees and shrubs get to a certain size and simply stop since "mature" (i.e., determinate) is clearly implied. What they want is certainty, predictability, Disneyland. (I also make frequent reference to indeterminate growth and the fallacy of mature size in my Rantings book) Moreover, people think of size as height (a linear measure) or width (also a linear measure), or height and width--thus a 2-dimensional measure--when in fact plant size is usually a 3-D or volumetric consideration. A shrub 6 feet tall and wide is twice as tall (often referred to as twice as BIG) as a 12' (high) x 12' (wide and deep) shrub, but the 12' x 12' shrub is actually about 3.5x bigger. An 8' x 8' shrub is only 1/3 taller than a 6' x 6' specimen but really is slightly more than 2x as big. Most people are not accustomed to thinking or visualizing that way, never mind the fact the plant "is still growing."

Additionally, plant labels info is often misleading. There are many woody plants on my property larger (both in linear and volumetric measure) than advertised and being woody they continue to get bigger. Know that how large a species or cultivar can get depends on a number of factors; e.g., how planted, where planted, atmospheric conditions, health of the specimen. While some species have it within their genetic constitution to potentially be bigger than others, they do not always. A deciduous azalea, one of my favorite shrubs, is going to be smaller than a comparably aged sweetshrub (Calycanthus) which is also a super shrub. Furthermore, the latter, sometimes also called Carolina allspice, has great size variation within the two species (C. chinensis and C. floridus) and their several hybrid cultivars. 'Athens' is the smallest of the lot at 5-6 feet whereas I have seen 'Aphrodite' specimens in excess of 12' x 12'. Both 'Athens' and 'Aphrodite' (shown above) are great shrubs but they vary in overall size as well as flower color (yellow-green vs. maroon), flower size (smaller {about 1-inch across with narrow tepals} and wonderfully fragrant vs. rose sized and only slightly fragrant, if at all) and leaf size (average vs. much larger, often almost pawpaw sized). Much of the published info on the overall size of 'Aphrodite' for example has the plant much smaller and without mention of indeterminate growth. The authors either do not know, presume you already know (NOT), or do not want to tell you since it might result in a lost sale. 'Micheal Lindsey' -- like 'Venus' hard to find -- is smaller with very fragrant dark burgundy flowers which are similar in size to 'Athens'. Note that older specimens of some shrubs, like Calycanthus, are often capable of getting even wider and deeper due to suckering but this can be controlled by timely pruning.

Because of this miscalculation and lack of understanding, many plants are misplaced--located (eventually) too close to other plants or structures. We have all seen it. Pruning, no matter how expertly done, cannot correct for poor choice of species/cultivar or improper placement.

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