eGarden © 2004 Ed Mues

From The Garden of Ed. Submitted for publication in The Towne Crier on March 24, 2004

Where Have All the Flowers Gone? AWOL?

Purchasing a plant, tree or shrub for the express purpose of seeing it in bloom is usually accompanied by a certain degree of excitement. It has already involved some decision making, including parting with some money. The reasons vary from property adornment, landscape improvement, finally settling on a focal point, or satisfying the "collector's syndrome" ... you know, if it's rare, the newest and latest, or extremely unusual ...you just have to have at least one so you can say, "Hey, everybody, look what I have!".

There are many additions to the world of ornamental horticulture arriving each year. If you're a plant person, it's easy to be enticed. The attraction is most often by way of flower and occasionally fruit, size, color, fragrance, shape, edibility etc.. I'm reminded of the story of the gardener who is so proud of his fern collection that he invites friends from his garden club with whom he wishes to share his ferns. After the visit draws to a close after many "oohs" and " aahs", he announces with pride that he plans to intersperse the ferns with anenomes the following year. A fellow gardener immediately comments, "With fronds like these, who needs anenomes?". (Forgive me. I can't help repeating this every so often.)

Every gardener loves flowers, and when they are absent without leave, especially after parting with money you thought would guarantee their presence, disappointment is certain. Whether it's a new ornamental crabapple, hydrangea, wisteria or exotic azalea, you long to get to the bottom of that sinking feeling that leaves you unfulfilled. You have a right to know what's going on... to peace of mind, or at least, peace with the plant world. It's time to take a step back.

A step back helps you gain perspective. First, recollect all of the reasons for making the plant choice that you did. There had to be many variables to consider. Did you do your best? It's your money, remember. Do you have as much knowledge about the plant in question as is available? Plants have preferences just as other living things. If you woke up in Chicago tomorrow morning, you just might not be a happy camper. A plant that awakens in your back yard this coming spring, just might not recognize the new surroundings as familiar or preferred.

Let's go on a little exploratory trip to examine the plant characteristics and preferred growing conditions that might to influence our plant choices.

Temperature:

The first qualifier we need to consider is hardiness. Hardiness according to the USDA has to do with the average annual minimum temperature (a.a.m.t.) in an area or region in which a plant will succeed. Succeed means survive rather than flourish. We live in USDA zone 5, with an a.a.m.t. of -20 degrees F. USDA zone 4 has an a.a.m.t. of -30 degrees F. A Zone 5 rated plant should survive our tougher winters, but that does not mean the flower buds will. Sometimes spring flowering plants only have flowers near the lower portions closer to the ground. What this suggests is that the flower buds beneath the protection of the insulating snow survived fine, but those above were damaged or killed by the severe cold. If you planted a Zone 6 plant, all you can do is hope.

Last year, my neighbors Bill and Ellen and I made a gamble. We planted a blue passion flower vine (Zone 6) right here in Sundown at the base of one of their stone houses with a south-eastern exposure. The reasoning was that the wall might hold and store sufficient heat to carry the plants roots through the winter. We don't care if the top dies to the ground as long as the roots survive. It is a very vigorous grower. But, I cautioned them that all they can do is hope. You, on the other hand, must weigh your investment and balance it against the risk of winter injury.

Still exploring temperature as a factor, I'm sure you recall seeing many beautiful flowering trees and shrubs come through the winter just fine with swollen, ripening flower buds. Suddenly, overnight, they are subjected to an unusual cold snap or unseasonable late frost or freeze that damages or kills many of the flowers.

Not an uncommon scenario when it comes to magnolias. This supersedes your careful choice. And, of course, other blooms are vulnerable, as well.

Light:

The vast majority of flowering trees and shrubs prefer a minimum of half a days direct sunlight or more. With a few under-story plant exceptions, inadequate sunlight is a major contributing factor for a plants failure to flower.

Soil:

I've mentioned in a previous column how important it is for a plant to have either preferred or acceptable soil structure, texture, drainage and pH, if the plant is to perform as expected. Planting over a shallow or poorly drained shale ledge will not be preferred by too many plants. Same, also, for planting on top of underground structures, pipes or other obstructions. On the other hand, if you've planted and examined the site carefully, and your plants seem to grow strong and healthy, but just don't set buds for flowers, it's time to examine what might have been overlooked. Correct pH is essential, even in the best situation, if a plant is to absorb the vital nutrients it requires to bud and bloom. It is well worth a new pH test and checking against what the plant prefers. If this checks out, we will move on to what else might have been overlooked. Stay with me, please. We'll get to the bottom of this problem, if we haven't touched on it yet.

Pruning:

One of the two most common causes of AWOL flowers is wrong time pruning. Careful observation or referencing your knowledge of when your chosen favorite sets its flower buds for bloom will inform you of when they are present and waiting for the right conditions. I'll use forsythia as a simple example: they bloom in early spring. If the plants are a little out of bounds as far as desired shape or expanse, prune them right after flowering. They will then reset vegetative growth and begin to manufacture food so the plant can begin to create next springs reproductive (flower) sequence of events. If you prune these plants in late summer, early or late fall, or very early spring, you are removing their spring flowering cycle.

Pruning seems complex as a care process, but it really isn't. Prune after flowering no matter what the time of year. Prune to correct problems, improve structure and overall shape. What comes to mind, immediately, is excessive pruning, sometimes justified as renovation of an old and tired plant you desire to bring back to renewed vigor. This is certainly the case for some rhododendrons, lilacs, azaleas, taxus, etc.. The consequences of such an activity are often forgotten.

The plant's response is lots of vegetative growth for quite some time, at the expense of reproductive (flower) growth. It will eventually return to balance.

Wisterias flower on the previous year's growth, so careful annual pruning is necessary to promote flowering.

Plant habit or characteristics:

Some perennial plants do not flower annually. Many are alternate bloomers, that is, they bloom every other year or, in some cases, every third year.

Back to the selection process, for a moment. When making a plant choice, examine and know the plant's blooming habits and characteristics. This can save you future anxiety.

Nutrition:

This is another area that can be particularly confusing. The notions of fertilizers, and the accompanying questions of ... yes?, no?, when?, how much?, what kind? ... can leave one's head spinning. And, often, if the issue is to solve a problem of AWOL flowers, it can seem to be complicated. It's not! A few ground rules might straighten it all out.

If you have full knowledge of your plants, the choices you made, and all the other variables, if they were planted correctly in an appropriate site with sufficient needs met, listen up. All plants, once well established, are autotrophic. This simply means they have the capacity to, and will in the best of circumstances, manufacture all the food they need through photosynthesis. Next item to note: Excess nitrogen results in excess vegetative growth, and, consequently, reduced or diminished reproductive growth. If your chosen favorite was planted in a lawn area, and the lawn is fertilized regularly, the high nitrogen that lawns require may well be keeping you flowering specimen in beautiful leaf (sans fleurs) mode. We are seeking the reproductive mode, not the vegetative mode. A healthy application of super phosphate (0-20-0) in late fall or early spring might perform a minor miracle.

Maturity:

You might not have thought about this, but whether your plant is an older or newer cultivar makes a big difference. Take the example of wisteria. If you have a wisteria that just refuses to bloom, it just might be an old cultivated variety that has a very long juvenile period that delays blooming until it is at least seven to ten years old. If it's a plant grown from seed, you ought to know it is not to be relied on for flower production. You might get lucky, in which case, if you have high flower production that you like, take cuttings and reproduce this one vegetatively. It might be a winner. Grafted plants are usually very reliable bloomers because the science had been done for you, and the price frequently reflects this.

I hope this has been helpful and has shed some light on where your flower production cycle might be amiss. Perhaps only a few steps will return your plants to provide the delights that you have been missing. Good luck.

From The Garden of Ed. Submitted for publication in The Towne Crier on March 24, 2004

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