Why your new plants are dying — and the cheap fixes

You planted a row a few weeks back. Looked sharp going in — good colour, nice and bushy. Then one morning you walk past and one of them has gone off. Leaves curling, brown creeping in at the tips, the whole thing looking sorry for itself. And the worry sets in: what did I do wrong?

Before you yank it out, here’s the bit worth knowing. Most of the time it’s not bad luck, and it’s rarely dear to fix. New plants die for a short list of reasons, and nearly all of them come down to water, depth, or the spot they’re sitting in. Sort those three and you sort most of your losses.

And if you’ve been quietly telling yourself you’ve got a black thumb — pull the other one. Everyone in this trade has killed plants. Heaps of them.

Case in point – I planted a lovely border of Choisya ternata (which hate wet feet) around our new concrete patio area. Although the soil was clay, it appeared as though it was on a bit of a slope and should be fine. A year later, all of the plants on the long edge of the patio had died – the only ones that survived were those close to the start of the patio and, tellingly, a few that were sheltered by an outdoor fireplace. The reason? Every time it rained, the fall of the patio from the house out to the long edge collected all that water and absolutely soaked the plants. Where the fireplace was, the water couldn’t run under it and the plants behind it thrived. So much for me being a green thumb!

First question: is it actually dead, or just sulking?

A plant that’s just been shifted often looks worse before it looks better. That’s transplant shock — not death. The top sulks for a bit while the roots catch up underneath.

Before you give up on it, do the scratch test. Scrape a sliver of bark off a stem with your thumbnail. Green and a bit moist underneath, and it’s still alive and worth nursing. Brown and dry all the way down, and it’s gone. Plenty of plants that look half-cactus in their first month come right once the roots get a grip.

Are you drowning it, or letting it go thirsty?

Water’s the number one killer of new plants — and it gets them both ways. Too much and too little look almost the same from the outside: wilting, yellowing, dropping leaves. So it’s dead easy to read it backwards and water a plant that’s already drowning.

Which way it bites you often comes down to where you garden. On heavy, wet ground — a lot of Southland, the low-lying parts of Canterbury — the cold months leave the soil sodden, and roots sitting in airless mud rot just as surely as they’d fry in a drought. Up in Central Otago it’s the other way round: the summers bake, the wind and sun draw the moisture straight back out, and a young plant with little root goes thirsty before it’s had a chance to settle.

Either way the check is free, and it’s the same one. Push a finger in past the first knuckle. Damp — leave it. Dry — give it a proper soak rather than a daily splash that only ever wets the surface. Don’t water to a schedule; water on what the soil’s actually telling you.

Did you plant it too deep?

This one catches more people than you’d think, and it’s a slow killer — the plant lingers, never quite fires, then quietly packs it in months later.

The collar, where the stem meets the roots, wants to sit right at soil level. Bury it and the stem stays wet and starts to rot. Plant it too proud and the roots dry out. Aim for the top of the root ball flush with the ground, or a whisker above. If you can’t see where the trunk flares out into roots, you’ve gone too deep.

Has the frost killed it — or just burnt the tips?

Frost cops the blame for a lot of deaths it never caused. More often it browns off the soft new growth and makes a plant look dreadful without touching the part that matters. So before you write one off, give it till spring and see what shoots from lower down — a frost-browned plant is usually sulking, not gone.

Where frost does real damage is on two things: tender species that were never going to suit a cold inland site, and soft growth pushed too late in the season with no time to harden off. And it’s not all one climate — a hard Central Otago frost is a different animal to a coastal one, so the further inland and higher you are, the more your plant choice has to earn its keep.

Or is the plant just in the wrong place?

This is the big one, and the cheapest to get right, because it costs nothing but a bit of thought before the spade goes in. Right plant, right place beats everything else you can do — and “right place” means your place, not the one in the catalogue photo. What kills a plant in one region keeps it alive in the next:

•      Wet ground (much of Southland, the low spots in Canterbury): the enemy is drainage. Things that hate wet feet, like the Choisya mentioned above, or Portuguese laurel (Prunus lusitanica), want a bank or a bit of raised dirt — drop them in a boggy corner and they’ll sulk and rot. Save the low, damp spots for natives that don’t mind it.

•      Central Otago: the enemy is the dry and the cold together. A plant has to take a baking summer and a hard winter, so lean on hardy, drought-tolerant stock, mulch it well, and keep the water up through that first season while the roots head down.

•      Canterbury and Christchurch: the enemy is often the wind. The nor’wester is a dry, desiccating thing that pulls the moisture out of new growth faster than you’d think. Shelter matters as much as soil — an exposed new plant cops it from the wind and the sun at once.

Could the wind be rocking it loose?

Wind’s the quiet one we forget, and most places get plenty of it. A new shrub that rocks back and forth in a gale never gets to grip — the fine new roots tear every time it moves, and the plant just sits there going nowhere.

If your spot’s exposed, firm the plant in well and stake it if it’s tall enough to catch the wind. A short, sturdy stake low on the trunk does more good than a tall one that lets the head whip about. Then take the stake off once it’s gripped — a year, give or take — so it learns to stand on its own.

Notice how little of that costs money. A finger in the soil, a plant set at the right depth, the right spot picked for your patch before you dig — that’s most of your losses sorted, and not a dollar spent. The dear mistakes are nearly always made before the plant goes in: wrong plant, wrong place.

That’s the thinking behind “grow south, plant north” — stock raised in cold Southland ground turns up in Central Otago or Canterbury already hardened off and ready for what those places throw at it. Get the spot right, and a good hardy plant is a lot tougher than it gets credit for.

If you’re not sure what’ll handle a particular spot on your place, that’s exactly the thing worth asking before you plant — not after.

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