10 gardening myths de-bunked

So much about horticulture is handed down the generations, but did the gardeners of yesteryear have it all correct?

We’re going to have a look at some of the old chestnuts this week with a view to rebutting a few……..

1. Compost in the planting hole.You know the old routine – you buy a plant, dig a big hole in the garden border, line it with plenty of compost, put in the plant, tuck more compost around it, water it, and there we are – job done.

But what you are creating effectively is a small ‘pot’ to contain the plant.  The roots are likely to go round and round the composted area and never start exploring the conditions of your garden soil. Result – stunted slow growth, poor anchorage and general disappointment. It’s like keeping a toddler confined to the nursery and not letting them explore the big outside world.

The answer is to mix the compost WITH the garden soil at the bottom of the hole and use 1 part compost to 2-3 parts soil for the backfilling.   Best of both worlds.  The texture and nutrition of the compost and a hefty taster of the conditions beyond.  

2. Have you heard the one about how you must never move peonies? It’s true that they will keep flowering for 50 years in the same spot, but you definitely CAN move or divide them.  It’s just a little tricksier than with most other perennials:

Choose early autumn, carefully dig up as much of the rootball as you can and critically, don’t plant the top of the rootball deeper than a couple of cms from the surface.  Ignore this rule, and you’ll get loads of lush leafage and no flowers – in other words, as useless as a knitted condom.

3. Companion planting, much-beloved by ye olden gardeners, is a more reliable nugget of wisdom. There are some fancy examples of this, for instance where you grow a combo of sweetcorn (as a climbing structure), beans (to fix nitrogen in the soil) and squash (to provide a living shady mulch).  Rather excitingly, that’s known as ‘The Three Sisters’ method!  

All I know is that growing marigolds and pots of mint in the greenhouse keeps all the nasty bugs away so I shall keep doing it. Planting nasturtiums to lure blackfly away from the broad beans seems rather harsh on the nasturtiums (Caroline’s fave) to me…. Crucially, no sprays used 👍

4. Am I allowed one more: you can’t plant things near a walnut tree. Walnuts have the anti-social habit of releasing a growth-stunting hormone called Juglone to reduce or kill the competition. Actually, some plants CAN tolerate this rude behaviour – forsythia, hydrangeas, hostas…. But apples, tomatoes or spuds for instance, will respond by dying pretty pronto.

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5. Native plants are better for pollinators. Well yes, there is some truth in this, but it’s nuanced … a long-running RHS study (read the full report via the link at the end) found that a garden plot planted with ‘near natives’, ie those plants from the Northern Hemisphere such as Europe, North America or China, had only 10% less insect life than a plot planted purely with ‘natives’. So Elaine will be very smug with her cottagey collection of roses, honeysuckle and (moveable) peonies. Unfortunately for me, the so-called ‘exotic’ plants from Southern hemisphere countries like South America, South Africa and Australasia, that I love, support 20% less invertebrate life, so I can see my sisters shaming me into running the London Marathon next year and donating my Just Giving proceeds to Bug Life as mitigation.

6. Garden plants do better with regular feeding. Not all of them do – in fact some do much worse! If a plant’s natural habitat is barren and impoverished, then it will have adapted over millennia to perform and flower well under these conditions. Feeding these plants will at minimum result in excessive foliage growth over flower production, and at worst, as in the case of proteas, so overwhelm them with unaccustomed nitrates and phosphates that they may die. Thus given that we should research, study and regularly observe our garden plants I much prefer the old Chinese proverb “The best fertilizer is the gardener’s shadow”. 

7. Watering in bright sunlight can scorch leaves. This myth is rubbish on so many different levels!
Firstly, on a scientific footing no plant would ever evolve leaves that scorch after a fleeting summer thunderstorm deposits water droplets on it. Secondly, you shouldn’t be watering the leaves in the first place – plants absorb water through the tiny hairs covering their roots so water should be directed at soil level underneath any leaves. Thirdly the most efficient time for watering is in the early morning or evening when the potential loss of this precious commodity to evaporation is least, and when there is unlikely to be any strong sunshine 😡

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Firstly, Laura may be able to see herself running the London marathon – the rest of us really can’t!

8. I’m generally a sucker for a myth and although we rarely have magpies here in the Highlands, the sight of one on its own has me touching wood within minutes. I know, I know, but the science surrounding the need to plant potatoes on Good Friday is just as flimsy.

The advice just means – don’t plant them too early when they might get frosted. Here it snowed all Easter weekend and was minus 3.5 at night, so my seed tatties were still cosied up in my porch. Generally you just need to wait until the day temperatures are reaching 10 degrees or more on a regular basis (for those of us who have no idea what our soil temperature is!).

9. The next myth I’d like to bust is that there’s a silver bullet for your slug and snail problem. It’s reminiscent of trying to solve your baby’s colic – buying all the products simply gives you something to do until the problem in fact, resolves itself. So fiddling around with copper collars, eggshells, beer traps and wool mats keeps optimism levels high, and to some extent deters the little blighters. But really the best advice is, don’t plant out too early (keep your babies in the greenhouse until they’re past the colic stage!) and just try to remove the slimy foe in the evenings wearing a head torch.

10. Finally – do you really need to move house if you’ve got endemic ground elder? No. Please don’t let a few ground elder outbreaks keep you awake at night. You’re very unlikely to eradicate it for all time – ground elder doesn’t understand Title Deeds or boundaries, and you can be perfectly civil housemates as long as it understands that it sticks to its bedroom; any incursion on the goodies in your borders will see a note firmly stuck on the fridge, aka, a purge with a razor hoe.

What gardening wisdom have you found to be just a myth – we’d love to hear…….

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Read more about the RHS research on supporting insect life in their Plants for Bugs Project Report.

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Louise’s Great Plant this Month is a small tree that is having the first of its several seasonal highlights right now. Read about its other virtues by clicking on the image below.

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Growing your own salad is really easy, whether in a pot on your balcony or in a veg patch. And April is a great time to get going, so here’s how!

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Are you starting to think about when you can plant out your tender plants for the summer ahead? A digital max/min thermometer is an invaluable ally in assessing whether they will thrive in the big bad outside world. Check them out in our shop here

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