DO I NEED A GARDEN DESIGNER, OR CAN I JUST BUY THE PLANTS MYSELF?
Sometimes, being honest, no. If you know your soil, you're willing to be patient, and you're happy to get some of it wrong (trial and error is 100% part of the process), you can absolutely do it yourself. Where a designer earns their fee is when the site's awkward, the budget's real money, or you want it right first time rather than after three seasons of not quite nailing it.
Gardening vs. garden design
Gardening and garden design aren't the same skill, even though people lump them together. Plenty of people are excellent gardeners. They know how to keep things alive, they've got a good eye, they enjoy pottering about, and they still end up with a border that doesn't quite hang together. That's because the bit that's missing isn't plant knowledge, it's composition: structure, repetition, working with the actual conditions of the site rather than what you fancy in the moment. That's a different skill, closer to spatial thinking than horticulture, and it's the one a designer's actually being paid for.
Which is usually where planting design earns its keep. Not choosing 'nicer' plants, but choosing ones that actually work together and survive where you've put them.
When DIY works well
If your garden's straightforward (decent light, reasonable soil, no major drainage issues) and you're not in a rush, buying plants yourself and learning as you go is a completely legitimate way to do this. You'll make some mistakes. Most of them are recoverable, a plant in the wrong spot can usually just be moved, and honestly, some of the best gardens are the ones someone's fiddled with and learned from over a decade rather than got perfect on day one.
When DIY gets expensive
Where it gets expensive to DIY is awkward sites: deep shade, waterlogged corners, steep slopes, exposed and windy plots. Or a garden that needs to work hard for the money already being spent on it, like a big landscaping project where planting gets treated as an afterthought and left with whatever's left in the budget. Or simply not having the time to spend three years finding out the hard way what doesn't work. If you're already paying a landscaper for a big build, getting the planting wrong on top of that is an expensive way to learn.
The middle ground: a planting plan alone
There's a middle ground too, worth knowing about. You don't have to choose between doing it all yourself and handing the whole thing over. A planting plan alone, without the full design and build, gives you a proper structure and plant list to follow. You do the buying and planting yourself, at your own pace, but you're not guessing which plants actually belong together or where.
Worth being honest with yourself about what you actually enjoy, too. Some people love the research, the trial and error, the slow build up of knowledge that comes from getting it wrong a few times. For them, doing it themselves is part of the appeal, not a cost to avoid. Others just want a garden that works, without the years of learning attached, and there's nothing wrong with paying to skip straight to that.
What you're really paying for
One more thing worth weighing up. A designer isn't just choosing plants, they're the person who's already made most of the mistakes you'd otherwise be making for the first time. That experience is really what you're paying for. Not access to plants you couldn't buy yourself, but a shortcut past the years it takes to learn which ones actually work together.
Honestly, there's no universal right choice here. It depends on the site, the budget, and how much you enjoy the process of getting it wrong along the way. Ask yourself which mistake you'd rather live with: a border that takes a few years to find its feet, or a budget spent twice because the first attempt didn't work. Either answer's a perfectly reasonable one to land on.
If you'd rather skip that part, that's exactly what paying a designer buys you. Not choosing 'nicer' plants, but choosing ones that actually work together and survive where you've put them.