Tag: Perennials

A Pruning Guide for the Squeamish

 

Pruning trees and shrubs correctly is not as difficult as some careful people may think, though pruning incorrectly is as easy as some careless people make it look. First, leave those shears in the shed. Shears are effective at cutting back herbaceous perennials and ornamental grasses, but are otherwise detrimental to the health of woody plants because they leave behind stubs. Don’t leave stubs!

Stubs are what is left of a woody twig or branch after the person pruning it has failed to cut it off at the proper place, which is close to a node where it joins the main plant, and instead has cut it haphazardly somewhere along its length. Shears by definition make cuts haphazardly on woody plants, even if at a distance the poor shrub looks neatly trimmed in shapes that some people find pleasing. Who hasn’t looked at a shrub minding its own business and thought, “That bush would be much more attractive shaped like a cube”? After several swipes of the shears, the bush appears neatly cubed from a distance, but upon closer inspection it will be evident it has suffered numerous wounds it will have trouble healing, if it can do so at all. Don’t leave stubs!


Treelion M45
Hand pruners – or secateurs – in use. Photo by Pellencgroup. The cut being made in the photo is too far out along the branch to be a proper pruning cut. It could be a preliminary cut intended to take away most of the weight of the branch to reduce the possibility of bark tearing away from the trunk when the branch falls loose. In that case, the final pruning cut should be close to – but not flush with – the trunk, as shown with the cut a bit higher on the trunk.

There are three principle reasons for pruning trees and shrubs, in descending order of importance.

  1. To preserve the safety and well-being of people, other animals, and property. Obviously, this applies primarily to trees, since shrubs are typically less capable of menace.
  2. To preserve or improve the health of the plant being pruned, such as by removing dead wood and crossing branches.
  3. Aesthetics, which of course is in the eye of the beholder, though the beholder should remain mindful of the precedence of reasons one and two, and of the vital importance of not leaving stubs.

Timing can be another critical aspect of pruning, and it can be confusing in light of differing requirements from plant to plant, with some requirements relevant to plant health and others to aesthetics, as in promoting or preserving flowering. In areas of the country with winter freezes, however, there is one general rule applicable to avoiding injury or weakening of a woody plant, and that is to refrain from any major pruning in the weeks leading up to the first frost in late summer and early autumn. The reason is that pruning encourages new growth, and tender new growth is susceptible to cold injury. The results are not apt to be catastrophic for the plant, but it will have wasted valuable energy on damaged top growth at a time of year when it would be healthier for it to be storing energy in its roots. It’s like shaking a person who wants to go to sleep.

Later in the year, in winter and especially in late winter, it is alright to perform major pruning on many woody plants because they are dormant. The plant’s hormones will not awaken it to push out new growth at that inopportune time. The exception is a sappy plant such as a maple tree. As anyone knows who has ever tapped a sugar maple tree for maple syrup, a maple produces sap copiously in late winter and early spring, and drawing too much of it at one time, as occurs in cutting off a major limb, will weaken the tree. It’s better to leave pruning of sappy plants until summer, when they will only dribble, and not gush, from wounds.



These are all great bits from a first series episode of Monty Python’s Flying Circus, but the portion relevant to this post begins at the 9:46 mark of the video.

 

If it seems this language of pruning is evocative of surgery on humans and other animals, the good reason for it is that the two procedures are more alike than different in their effects, and it is helpful to be aware when pruning that you are making cuts into a living organism. Too many people with shears, particularly the mechanical kind, appear to proceed blithely without any awareness that their hedges and foundation plantings are composed of living organisms that must expend energy recovering from an assault with carelessly wielded cutting implements.

As for appearance, while there are few people who can carry off the page boy haircut look successfully, there are for some bewildering reason an awful lot of people who think the plant equivalent of that haircut looks just dandy on their shrubs. If the shrubs themselves could speak, they might express a preference to be left alone to allow their natural beauty to shine through, with only an occasional light touch from a deft hand to help them look their best. Most of all, to keep trees and shrubs beauteous and robust, don’t leave stubs!
— Izzy

 

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A Confusion of Mums

 


How hardy are the chrysanthemums sold at nurseries, garden centers, and grocery stores in the fall? What is a Dendranthema mum? Are any of the mums used for a fall display going to survive if planted in the ground afterward? The answers are “somewhat”, “no one really knows”, and “maybe”. Welcome to the wonderful world of chrysanthemums, a flowering plant second in popularity only to the rose, and just as susceptible to hybridization and the fickleness that is often a byproduct of botanical experimentation.

 


If a gardener is concerned at all about procuring a truly hardy, perennial mum when out shopping, he or she might be better off disregarding most of the confusing nomenclature and instead following the rough rule of thumb that the more daisy-like the chrysanthemum flower, the hardier the plant. All those pom-pom and button flowered cultivars have been created by plant hybridizers who were motivated by producing what they presumed to be the showiest flowers, in profusion and in a wide range of colors. As in anything else in life, there are trade-offs, and in the case of hybridized chrysanthemums, generally known as florists’ mums, the trade-off for an abundance of puffed up flowers in nearly every color was a weakened plant that many buyers treat as a tender annual.


Reading in the garden, (15468717167)
A mass of Korean chrysanthemums in bloom in October 2014 at the Conservatory Garden of New York City’s Central Park. Photo by Flickr user David McSpadden.


Here is a plant that has a short season of bloom, typically lasting only a month, which is not bad for a perennial, but is terrible for an annual. What makes most annuals a good value for gardeners is their tendency to bloom continuously for three or more months. Plant them in a particular spot in the garden and they will fill it with color for a season. Some annuals reseed themselves, making them yet a better value. Perennials typically flower a month or two in the year, but since gardeners don’t have to buy new ones each year, they are a good long term value. Many perennials also increase themselves by various means, such as underground runners in the case of truly hardy chrysanthemums.

The florists’ mums that take over stores in the fall are a marketer’s dream plant. Firstly, they demonstrate very well the axiom that “the flower sells the plant” because they have flowers to spare when the plants are at their relatively brief peak period of bloom. Secondly, their fickle requirements for success when planted out among the other perennials in a garden ensures they are only nominally perennials and are in practice annuals, and that translates to turnover for sellers, a yearly marketing bonanza as buyers get new plants each year. Lastly, the genetic pliability of chrysanthemums rewards the efforts of plant hybridizers to produce new and unusual cultivars year after year, driving novelty in the market and the higher profits accruing to patented plants.
Chrysanthemum zawadskii1
Chrysanthemum zawadskii in Osaka, Japan. Photo by KENPEI. These are also known as Korean chrysanthemums. The confusion of names makes plant selection difficult for people, but honey bees have no difficulty choosing to visit the flat, open flowers of these truly perennial chrysanthemums, which they prefer over the often tight quarters of the flowers on florists’ mums.

For gardeners who can’t resist picking up a few florists’ mums in the fall, the good news is that they can plant them out and get more than one brief season of bloom from them if they educate themselves about the plant’s requirements and take great care with them the first winter at least. Many gardeners may decide coddling florists’ mums is not worth the trouble, and for them the most pleasing mum in their gardens will be the truly perennial chrysanthemum, and it goes by many names, most often Dendranthema. There is a confusing history to that genus name, a name which for much of the late twentieth century actually applied to all chrysanthemums. Or most of them. It’s hard to tell. Probably it’s best not to bother about it too much. The truly perennial mums can be hard to find in plant nurseries and shops, and much easier to find in old cottage gardens. They’re the waist high mounds of plants covered in masses of daisy-like flowers that honey bees love visiting.
— Izzy

 

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