That's a question that has been occupying the attention of the Horticultural Trades Association for some time. And it's important since this age group accounts for 29% of the population.
A workshop last October followed by research earlier this year provided some insights, and these were presented by David Arnold at a seminar I attended at the National Plant Show.
Different Reasons Why
Busy lifetstyles and other priorities are important factors - unsurprising since people at this age will probably have young families.
Money is another consideration, everyone has a budget and gardening can slip down that list of priorities.
Many will be living in rented accommodation, so why should they bother to beautify a garden if they are soon to move on?
Gardening is seen as a chore rather than a joy, leading to discomfort. After all, who wants to get their manicured nails dirty. Finally, previous bad experience may lead to a lack of confidence and interest.
A key aspect of the research indicated that although not embracing gardening, the target age group enjoy having a garden to relax and socialise - eating and entertaining rather than planting and pruning.
What Can Garden Centres Do?
Many of the target group don't visit garden centres as they find them confusing and intimidating, so how about organising 'outdoor living weekends', creating before and after cameo gardens, and becoming more inviting, approachable and helpful to reluctant gardeners.
The research also came up with the surprising quote that 'gardening was for old people', a sobering thought for those of us who thought it was back in fashion.
How To Get The Message Across
This is a subject that Gardensite has successfully addressed for some time. It might have a garden centre and be an online garden retailer, but it's of no use if you don't let everyone know you exist.
Gardensite realised that the most effective way to connect with the younger age group in question, who are likely to receive most of their information on mobiles and tablets, is through social media.
That's why The Gardener blog is being developed into a thriving online information resource.
You can also follow gardening activities on Google +, Facebook and Twitter, and get to know what is in stock in the garden centre and what online products look like on You Tube, Instagram, and Pinterest.
We all know that gardening is a rewarding and enjoyable activity, and Gardensite will continue to communicate that to all age groups in the most effective ways.
I would love to hear you thoughts on how Garden Centres and Gardensite can be more helpful and inspiring.