There is a wonderfully strange experiment in consumer psychology involving jam.

Not plants. Not cars. Not mortgages.

Jam.

Researchers Sheena Iyengar and Mark Lepper set up a tasting display in an upscale grocery store. On some occasions, shoppers encountered 24 varieties of gourmet jam. On others, they encountered only six.

The big display did exactly what you might expect.

It attracted people.

More shoppers stopped when there were 24 jams to investigate. The abundance was interesting. It created spectacle. It suggested possibility.

But then something peculiar happened.

The smaller display sold more jam.

Quite a lot more.

That experiment became one of the most famous demonstrations of what came to be called choice overload, the idea that increasing the number of alternatives can sometimes make a decision harder rather than easier.

It is a seductive idea for anyone in retail.

Perhaps we simply carry too much stuff.

Except that is not quite what the research says.

And for horticultural retailers, the distinction matters enormously.

People Like Choice

There is a perfectly sensible economic argument for assortment.

More choice should be good.

If a garden centre carries three clematis varieties, there is some chance none of them will appeal to a particular shopper. If it carries twenty, the probability of finding exactly the right colour, height, flowering habit and garden use should increase.

Choice also communicates something.

A broad assortment can make a retailer appear authoritative. It creates possibilities. It encourages browsing and discovery. It gives experienced gardeners the freedom to look for something unusual.

This helps explain why the large jam display attracted more attention in the original experiment.

Abundance has appeal.

The trouble begins later.

At some point, the customer has to stop admiring the options and choose one.

Those are two very different psychological tasks.

Consider the Clematis Bench

Imagine a gardener standing in front of fifteen clematis varieties.

To someone in the horticultural industry, the differences may seem obvious.

Different cultivars.

Different colours.

Different flower sizes.

Different heights.

Different bloom periods.

Different pruning groups.

Different degrees of hardiness.

Different garden applications.

To the consumer, however, the decision can quickly become something else.

Which one is best?

Is the more expensive one better?

Will this one get too large?

Does that one flower longer?

Will either survive my winter?

Do I have to prune it?

What does pruning group two mean?

Would the purple one look better than the pink one?

And after several minutes of comparison, perhaps the most commercially dangerous thought arrives:

I’ll decide later.

This is where assortment becomes economically interesting.

The cost of a product is printed on the price tag.

The cost of choosing it is not.

But the consumer pays both.

Decisions Have a Cost

Every comparison requires mental effort.

That effort rises when products differ across several dimensions at once.

A shopper comparing two nearly identical boxes of tissues may need to consider price, quantity and perhaps softness.

A shopper comparing plants may be processing:

• mature size
• colour
• bloom period
• hardiness
• exposure
• moisture requirements
• maintenance
• growth habit
• disease susceptibility
• expected longevity
• price

Now multiply those attributes across fifteen or twenty varieties.

This is no longer simply a large assortment.

It is a large decision problem.

That distinction helps explain why the research on choice overload initially appeared contradictory.

The Jam Experiment Was Not the End of the Story

After Iyengar and Lepper published their famous work in 2000, researchers tried to reproduce choice overload in different settings.

Sometimes they found it.

Sometimes they didn’t.

In 2010, Benjamin Scheibehenne, Rainer Greifeneder and Peter Todd conducted a meta-analysis and concluded that the average effect across the research they examined was much weaker than the popular interpretation of the jam experiment suggested.

In other words:

More choice does not automatically paralyse consumers.

That could have been the end of the idea.

Instead, it produced a better question.

Not:

Does too much choice hurt sales?

But:

When does too much choice hurt sales?

Alexander Chernev, Ulf Böckenholt and Joseph Goodman later examined 99 observations involving more than 7,000 participants.

They identified four conditions that make choice overload more likely:

• the alternatives are difficult to compare
• the decision itself is complicated
• the consumer is uncertain about what they want
• the consumer is trying to minimize the effort involved in choosing

That list should sound rather familiar to anyone who has watched an inexperienced gardener shop.

Plants can be complicated.

Differences between varieties are not always obvious.

Many customers enter the category without a clearly defined preference.

And most did not arrive hoping to spend twenty minutes conducting a comparative cultivar analysis.

The issue is therefore not simply how many plants we put in front of people.

It is how much thinking we require before one of those plants can be chosen.

Fifteen Choices Are Not Always Fifteen Choices

Suppose a garden centre carries fifteen rose varieties.

If every rose is visibly different, the assortment may be relatively easy to navigate.

One is yellow.

One is deep red.

One is compact.

One is highly fragrant.

One is clearly suited to colder regions.

One is dramatically larger.

The assortment contains fifteen products, but the products provide the consumer with meaningful distinctions.

Now imagine fifteen roses that appear remarkably similar.

Ten are shades of pink.

Several have comparable flower forms.

Prices are close.

Differences in disease resistance, mature size or flowering performance exist, but they are difficult for the shopper to recognize.

Technically, the store still has fifteen choices.

Psychologically, it may have created fifteen questions.

This is an important distinction.

Choice overload is not merely a problem of quantity. It is a problem of comparison.

A large assortment of clearly differentiated products can be easier to shop than a smaller assortment of products whose differences are difficult to understand.

Similarity Can Be Expensive

Retailers understandably like assortment depth.

It signals expertise.

It provides options.

It allows enthusiasts to find precisely what they want.

But every additional SKU should earn its place not simply by being different botanically, but by being meaningfully different to the customer.

That creates an uncomfortable question:

If two varieties require an expert to explain why they are different, how different are they at retail?

That is not an argument against horticultural innovation.

Quite the opposite.

Our industry is extraordinarily good at creating improved genetics and increasingly specialized cultivars.

But genetic differentiation and consumer differentiation are not always the same thing.

A breeder may see a meaningful improvement.

A grower may see a meaningful improvement.

A nursery buyer may see a meaningful improvement.

The shopper may see another pink flower.

When that happens, adding an option can increase the analytical workload of the assortment faster than it increases its perceived value.

New Research Makes the Story More Interesting

A 2024 study published in Marketing Science provides a useful modern twist.

Olivia Natan examined consumer behaviour on a large online food-delivery platform and studied what happened as product assortments expanded.

Larger assortments helped attract new consumers.

That makes sense.

Variety is appealing from the outside.

But among consumers who remained on the platform, larger assortments reduced purchase frequency. The research points toward costly attention and the burden of choosing as part of the explanation.

That finding is particularly interesting for garden retail because it exposes the two faces of assortment.

Selection can attract.

Selection can also exhaust.

Those effects can exist at the same time.

A spectacular garden centre filled with hundreds of varieties may be enormously appealing as a destination.

But the very abundance that produces the initial impression can make individual category decisions harder once the shopper begins trying to buy.

The merchandising challenge is not choosing between abundance and simplicity.

It is achieving both.

The Real Metric May Be Decisions per Purchase

Garden retailers traditionally think in units such as:

SKUs.

Pot sizes.

Facings.

Linear feet.

Inventory turns.

Sell-through.

All of those matter.

But behavioural economics suggests another useful measurement:

How many meaningful comparisons must the customer make before purchasing one plant?

Consider two displays.

Display A contains twelve varieties, but choosing requires comparing hardiness, mature size, exposure, flower period and pruning requirements across nearly every option.

Display B contains eighteen varieties, but the distinctions between them are immediately understandable.

Display B is technically larger.

It may nevertheless be psychologically smaller.

That is a useful way to think about assortment productivity.

The objective is not necessarily fewer SKUs.

It is fewer unnecessary comparisons.

Assortment Should Earn Its Complexity

This suggests a harder standard for product selection.

Every additional variety creates potential value.

It also creates potential decision cost.

The commercial question is whether the first exceeds the second.

Before adding another variety to a retail assortment, ask:

• Does it satisfy a meaningfully different consumer need?
• Is its advantage understandable without extensive explanation?
• Can a shopper distinguish it from neighbouring alternatives?
• Does it expand the market, or merely divide an existing decision into smaller pieces?
• Does it create incremental demand, or incremental hesitation?
• If it disappeared, would the consumer genuinely lose something important?

That last question may be the most revealing.

Because horticultural businesses naturally evaluate assortment from the supply side.

Can we grow it?

Can we source it?

Can we list it?

Can we ship it?

Can we fit another variety on the rack?

The customer is answering a different question.

Does this extra option help me make a better decision?

Those are not always the same thing.

The Most Dangerous Sale Is the One That Never Happens

When retailers think about lost sales, they often imagine a customer choosing a competitor.

But consumer research on decision deferral points to another possibility.

The shopper simply chooses nothing.

Ravi Dhar’s work on the no-choice option showed that when preferences are uncertain and alternatives are difficult to distinguish, consumers can become more likely to postpone the decision rather than select an available option.

In a garden centre, that behaviour is almost invisible.

There is no abandoned shopping-cart report.

No notification.

No receipt marked:

Customer liked several plants but became uncertain and left.

The customer simply walks away from the bench.

Perhaps they tell themselves they will think about it.

Maybe they will.

But horticulture is seasonal.

The weather changes.

The weekend ends.

The garden project gets postponed.

Another expense appears.

The moment passes.

The lost sale leaves almost no evidence behind.

More Is Valuable Until More Becomes Work

The lesson from choice overload is not that garden centres should become smaller, duller or less interesting.

Choice is part of what makes horticulture extraordinary.

Gardeners love discovery.

Collectors love variety.

Experienced consumers often want depth.

And a great nursery should retain the ability to surprise people.

But assortment has a cognitive price.

The more similar the options become, the more attributes the shopper must compare, and the less certain they are about what they actually want, the higher that price becomes.

That is the real paradox.

A retailer can add inventory, add genetics, add colour and add choice while unintentionally subtracting something equally valuable:

the customer’s ability to decide.

Perhaps the better assortment question is therefore not:

How many varieties can we offer?

It is:

How many varieties can the customer meaningfully choose between?

Those numbers are not necessarily the same.

And somewhere between them may be a surprising amount of lost revenue.

Sources

When Choice Is Demotivating: Can One Desire Too Much of a Good Thing?
Sheena S. Iyengar and Mark R. Lepper, 2000.

Can There Ever Be Too Many Options? A Meta-Analytic Review of Choice Overload
Benjamin Scheibehenne, Rainer Greifeneder and Peter M. Todd, 2010.

Choice Overload: A Conceptual Review and Meta-Analysis
Alexander Chernev, Ulf Böckenholt and Joseph Goodman, 2015.

Consumer Preference for a No-Choice Option
Ravi Dhar, 1997.

Choice Frictions in Large Assortments
Olivia R. Natan, 2024.

The “Less Is Better” Paradox and Consumer Behaviour: A Systematic Review of Choice Overload and Its Marketing Implications
Sangeeta Sahney and colleagues, 2024.