10 Ways to Naturally Kill a Plant!

You may have noticed that last spring, articles on the blog became less frequent... To be honest, we experienced what we modestly call "a period of intense growth", which means it was hot, very hot indeed! To tell you the truth, it felt like all the gardeners in France and beyond had decided to frantically place orders. Let’s just say that everyone was on deck, and even the boss was preparing the parcels. As a domino effect, those of us, like me, who were a bit "hidden" behind our advice sheets found ourselves responding to emails from worried, even desperate gardeners facing their dying plants. This sometimes challenging experience was rich in lessons, as I can confidently say I now know how our clients manage to kill their plants in their gardens!

Here’s how they go about it!

1) They use heather soil, pure, preferably.

Using heather soil starts, we agree, from a good intention: to provide an appropriate substrate for acidophilous plants (like Japanese Maples, rhododendrons, hydrangeas...), which need a slightly acidic soil (pH between 4 and 6.5) to thrive. It’s also a logical approach because in the term "heather soil plants," there is "heather soil." Finally, if the local garden centre sells it, it must be good to use! Well, believe it or not, it’s not, because heather soil is a substrate that seems to have been invented to make plants die.

Indeed, heather soil, which contains a significant amount of blonde peat, is certainly acidic but it is also very low in nutrients. Furthermore, when it is soaked it often retains too much moisture, and when it is dry, it is nearly impossible to rehydrate; water just runs off it but does not penetrate the heart of the plant. As a result, it is impossible to properly water a plant in pure heather soil. And worst of all, the plant that manages to grow will just struggle and eventually die due to a lack of substantial nutrients!

To learn all about planting heather soil shrubs, check out Michael's article:

2) They water every day, a little... or every day, a lot... or never.

80% of replanting issues are due to overwatering or underwatering.

The problem is that an overwatered plant shows roughly the same signs as a plant that is not watered enough: wilting leaves that dry out and eventually fall off. Faced with these symptoms, the first reflex of inexperienced gardeners is to water again, more often and more abundantly... until death ensues, or nearly. Those who do not water generally do not speak up: they often realise their neglect when it is really too late and no rescue measures are possible. In truth, I think they feel a bit ashamed.

Our advice for proper watering is simple: to know if your plant needs watering, touch the soil! If the soil is damp and your finger comes out muddy, it has too much water, so stop watering. If, on the contrary, your finger comes out dry and without soil, water it; it is too dry! The ideal is to keep the soil always fresh and loose, where your finger comes out slightly damp with a bit of soil stuck to it. And the hotter and drier it is, the more you should not water, but check the moisture at the base of the plant. Also, consider your plants' needs: a lavender plant does not need constantly moist soil, while butterbur, planted in regular soil, does.

3) They install frost-sensitive plants... where it freezes, hard and often.

The notion of hardiness sometimes leads to very personal interpretations, bordering on the fanciful. For many gardeners, a hardy plant is a robust plant (a bit like our grandparents' furniture... so far, so good) capable of withstanding Siberian cold, everywhere in France (that’s where things go awry). Indeed, there are several degrees of hardiness, and a plant will not react the same way in all gardens... because its age, exposure, soil type, and drainage also matter.

It frequently happens that optimistic gardeners living in harsh climates like Alsace, the Vosges, or Aveyron realise their exotic garden dreams with a lot of callistemons, Musa basjoo, or Gunnera... Generally, they call us in spring to report that their plant has not taken. And, of course, we can do nothing!

To avoid this type of inconvenience, take the time to read the information contained in the plant sheets: hardiness is clearly indicated! And to learn all about hardy plants and the concept of hardiness, feel free to consult our complete dossier:

4) In pots and containers, they use garden soil and rely on the sky for watering.

Sometimes it works. Often, it does not.

Growing plants in pots may seem simpler. In reality, it is not that easy. Not only do you need suitable containers, but you also need, above all, a quality substrate.

What could be better than garden soil? Indeed, when it is rich and light, it works. When it is heavy, a bit suffocating, or stony and very draining, it’s a whole different story. In pots, plants must make do with little: a reduced volume of soil and the water that we are willing to give them through watering. Moreover, their root system is necessarily a bit constrained. These plants are therefore more sensitive to potential nutrient and water shortages. To have beautiful potted plants, the quality of the substrate is therefore crucial! Instead of digging who knows where to beautify your balcony or terrace, invest in quality, nutritious potting soil that retains water well. If possible, choose from professional quality ranges (like Klasmann), and use it pure, without trying to make improbable mixtures like: Aunt Brigitte's garden soil + sand from the nearby construction site + the old geranium compost from the neighbour below.

To learn all about the different types of potting soil and their use, check out our advice sheet:

Regarding watering, do not rely on rainwater. Even if it floods your garden, it is unlikely to be enough to meet the essential needs of your potted plants. Why? Because, often, the leaves form a barrier that prevents rainwater from penetrating the soil, and then, because pots, unlike garden soil, do not retain moisture for long. Potted plants must therefore be watered, without excess, but as soon as they need it (see above) and especially, all year round, even in winter, after a severe frost or if the weather is dry.

5) They plant quickly (and poorly), in concrete-like soil or, conversely, too worked and fertilised soil.

We trust our clients, but, as we know our plants well, some failures leave us puzzled. To be sure, we ask for a photo of the dying plant, in situ. Let’s just say that we have a collection of images that could open a real little museum of gardening horrors: perennials planted in compact soil, visibly as hard as concrete, understorey plants in stony soil, shrubs planted in the lawn for which only a hole the size of the pot was dug...

On the contrary, some go to great lengths and fertilise with wheelbarrows of manure, sometimes fresh. The road to hell is paved with good intentions.

Let’s remind ourselves once and for all: apart from a few very greedy vegetables like squashes, plants do not need such inputs. And when a plant likes rich soils, we are talking about humus-rich soil... rich in humus that will be the result of the slow decomposition of balanced compost, good leaf mulch, or green waste... but, under no circumstances, brutal fertilisations or those too rich in nitrogen that, on the contrary, weaken them by making them grow too quickly or, at worst, burn their roots.

For plants to thrive, they need a welcoming environment: soil, more or less rich (but never too much) at least well loosened. You need to dig a comfortable hole, wide enough for it to spread its roots. Remember, in this regard, to gently untangle the root hairs before planting. This simple gesture will allow the rootlets to make contact with their new soil. Also, be mindful of competition: if we advise planting in weeded soil, it’s not just to make you sweat; it’s to allow your little newcomers to gather strength before having to make their place in the sometimes hostile environment of the garden!

And if you think it’s really difficult to mess up planting perennials, feel free to take a few lessons!

6) They plant rhododendrons in calcareous soil, agaves in wet soil...

Who knows why, but multi-recidivist plant killers all have one thing in common: they dream of what they cannot grow at home, like hydrangeas in calcareous soil, Gunneras, or a shrimp willow in dry soil, agaves in wet soil. The problem is that they take action and plant anyway (sometimes adding heather soil, see point 1...). Inevitably, at best, the plant struggles fighting against chlorosis or root rot, at worst, it dies. It’s usually at this point that they call customer service for a replacement (yes, I assure you!).

To err is human, to persist is diabolical.

If a type of plant does not suit your soil, your climate, stop insisting and adopt "The right plant in the right place" as your mantra!

As with hardiness, the information regarding the type of soil required to grow plants is included in the descriptions of our plants. Read them, take them into account, or take some time to consult a reference book like "All the plants, for all desires and all situations" by Didier Willery.

7) They fall for a perennial or a shrub without knowing exactly where to place it.

A slight variation on the previous point, this mistake is often made by experienced gardeners whose garden is already bursting at the seams... because they too often fall for... a new charming variety, a rare species, or a crush during a plant fair. Three clicks and 48 hours later, these same gardeners are wandering the garden, the new addition in hand, looking for a little spot. It’s usually after 20 minutes of wandering that they find a few square centimetres to squeeze it in. Along the way, they will have forgotten its requirements and, despite their experience, they will have planted a shade plant in full sun (or vice versa). The plant may not necessarily die, but its foliage may look sad or it may not flower... which will undoubtedly earn us a little remark!

Moral: not planting a plant in the right place is not just the domain of beginners. Experienced gardeners can do it just as well...

8) They plant on the day of delivery, even in heatwaves or severe cold... or they wait, a long time.

Our plants are delivered all year round, in pots or containers. Weather conditions mean they sometimes arrive at an inopportune time: severe cold, intense heat, or waterlogged soil... Some even plant anyway, armed with an ice pick and a headlamp (it gets dark early in winter). Let’s just say that this compromises their establishment.

We also sell plants in vegetative rest (we explain why in this article), with no visible signs of life or just a few small leaves. I won’t dwell on those who angrily throw them in the compost (they are rare... and I consider they are cases we can do nothing about) but rather on anxious gardeners, who, even when conditions are ideal, are afraid to plant such small "things" in the garden and decide to let them "harden off." Once again, letting plants grow comes from a good intention. The problem is twofold: the pots in which the plants are sold quickly become too small, nutrients deplete quickly, and, above all, potted plants need almost daily watering! Result: the plants die. My advice: do not necessarily plant as soon as you receive them, but plant as soon as possible!

Please, we no longer want to hear "I know it’s hardy, but I’m going to wait until after the Ice Saints to put it in the garden" or "I’m ordering now, I know it’s not the right time, so I’ll keep it in a pot and plant in October"... or else, promise us to: 1) repot the plant in a much larger pot, 2) use good potting soil, 3) ensure regular watering whenever necessary until planting in the ground.

Finally, as a side note, know that no, keeping plants in a garage during your holidays, even with the light on, is not possible!

9) They prune, without knowing why or how, but they prune!

For some, it’s an obsession: they must prune. It doesn’t matter when, why, or how, nothing must stick out, so they chop away. If the shrub is of the friendly type (hornbeam, boxwood, Lonicera nitida...), things generally go well. Where pruning becomes problematic is:

• when they prune down to the ground shrubs that cannot tolerate it (like Japanese maples, daphnes, forsythias...),
• when they prune at the wrong time: at the end of winter for spring-flowering shrubs or at the end of spring for summer or autumn-flowering shrubs.

To be completely honest, a bad or excessive pruning rarely kills a plant, but this massacre with shears will deprive you of blooms and will cause the shrub to lose the harmony of its natural shape, which is somewhat similar!

Remember: pruning a shrub is not always necessary. If you don’t know how to prune, do nothing without informing yourself!

10) They worry.

"Don’t worry, it just got a bit hot, give it some water" "Yes, it will grow, I assure you" "No, white spots are not a serious disease", "It’s just a pest, there are many this year".