RIP cordylines

Last spring I planted two small cordylines in two homemade planters. They put some fantastic growth on and heading into winter they looked great.

Fast forward to now, after loads and loads of wet weather, and both cordylines are looking really really bad.

I have a couple of theories as to what's gone wrong, and both, I suspect, would have led to their demise.

1. Although I drilled a lot of holes in the bottom of the planters i believe that a lot of them could have become blocked over time. And with all the wet weather recently, I believe that root rot has well and truly set in because the drainage has been compromised.

2. In my naivety, when planting my cordylines last spring I simply backfilled the planters with plain garden soil. I've since found out this is a cardinal sin when gardening as plain garden soil, when settled, over time, compacts and offers little in the way of adequate drainage.

My plan is to wait until spring now and buy two more. But what is the best way forward regarding improving my planters and what type of soil mix should I be using. Drainage, I believe, is absolutely key to prevent this happening again.

 

Are you sure its a drainage/ rain problem, and not frost damage?
Have a look here, Cordyline Calamity

Often just raising the pots off the ground can improve drainage.

I agree, best to not use garden soil in pots.

 

Primarily, due to my own stupidity, I believe excess moisture due to poor drainage is the main culprit, but of course frost would compound the problem further too.

Either way they're beyond salvaging now, I need to learn from this.

Is it also essential to put broken croc at the base of the planters to aid drainage? I didn't!

 

I've never used crocks in the bottom of pots, it just takes up useful compost space.
I'd tend to use a JI compost with about 25% extra sharp sand added, you could use grit.

Dont over pot, move the plant up into bigger pots slowly, ie, if it only a small plant when you buy it make sure you dont put it into a pot that it cannot fill with roots by the end of the growing season.

Frost has been the biggest problem this year, do you have any pics.

 

It's night time now, I'll take a pic tomorrow.

The planters I made are relatively large, and the cordys were only small when I planted them. I thought the small cordys would enjoy the large root space that the planters give them and that they'd fill the planters out more over the years, no need to keep repotting/upgrading that way.

Is this the wrong way to do it then?

 

Yes, not good putting a small plant in a very big pot, you need to up the pot size as the plant grows until you reach the required finished pot size.

So maybe 4ins in diameter bigger, when young, for something like a cordyline and only repot in spring.
That way it doesn't get waterlogged and the roots get to use all the available compost.

Growing in containers is not the same as growing in open ground.

 

It's not recommended to put small (especially tender) plants into big containers. There's too much unoccupied compost (or soil) for too long and it goes stale and waterlogged, causing root rot. I do put crocks over largish drainage holes simply to stop the compost oozing out, but not a thick layer over the bottom of the pot. As pete says, it takes up valuable space and if you've got the soil/compost/grit mix right, there's no need for it.

 

Well, you live and learn, everyday's a school day for me when it comes to gardening. That's why I joined the forum, so more knowledgeable people could help me.

 

Rather than using crocks, I use prunings and twiggy stuff to go in the bottom of larger pots. It'll break down eventually, but it provides a much better drainage...plus it saves on compost.
I've heard the argument about putting brown twiggy stuff in pots and as it decays it takes all the nitrogen away from the plant roots/puts too much nitrogen near the plant roots
I've never had problems so I'm calling that BS

 

This is a pic of my suffering cordy. The drooping outer leaves are to be expected I suppose, what with the snow. But if you zoom into the centre crown all the leaves are yellow, this is my concern.

Is this too much moisture related/poor drainage, or frost, or something else? It may very well recover but I'm not too confident.

 

I'd say probably frost combined with soggy conditions.
The weight of the snow probably didn't help either.

 

Cordylines prefer an alkaline environment, ph6-8. Therefore composts need addition of lime, dolomite chips or calcified seaweed. A free draining container and protection from wind stress and foul weather.
Some more information here:
How to grow cordyline / RHS Gardening