Erythrina crista-galli

This is a picture from the internet of Erythrina crista-galli, for those who don't know it - sadly not mine.

My question - is how do you overwinter it? I have three grown from seed that are still young and haven't flowered yet. One is inside my garden room and will be overwintered at 10C, and the other two are outside. They are all losing their leaves. I have seen talk in the past of cutting the stem back to the ground, rather than just leaving it as you would a deciduous tree. I would appreciate any information.

Also, is it easy to get to flower even inside a greenhouse? Chad on HTUK forum said

 

This is my photo but sadly not my plant....................


It was taken at OBG where it is planted in the shelter of a south facing wall. As far as overwintering goes mine was in a frost free garage until I planted it out.
I've allowed my seedlings to take an air frost to sort out the RSM - they are caviare to spider mite.

 

Must admit my two plants have not flowered this year.

But I tend to overwinter dry, in the unheated garage.
I nearly lost one plant the year before last as the stems kept dying back, and back, right back to the rootstock, it then took ages to reshoot from underground in the spring.

Since then I try to keep at least the bottoms of the stems alive, the trick being, (I think), it to make sure the wood ripens well in the autumn.
I do that by pushing the pots over in early September, letting them dry out in full sun and the leaves to drop.
Hopefully mimicking the dry season
I then cut back to solid wood about a month later.
Then no more water until March at the earliest.

I agree it is a plant that likes heat, in fact I've found that if flowers form after Aug, they rarely open properly.
But personally I'd not want it to get frosted whilst wet either.

 

Mine was dryish and it was just an air frost.

At OBG it also receives a thick leaf mulch. It flowers year in year out.

 

I saw one planted outside at Wisley a few years ago, not sure how well it flowered,it looked a bit weak when I saw it, it was planted close to one of the buildings wall.

I've thought of planting out.
I did plant one out some years ago.
It rotted first winter, so I'm a bit hesitant now.

 

"Just an air frost", you mean below zero?

 

The one at OBG is against the wall of one of the heated glasshouses, so maybe some residual heat in the brickwork. It is also in full sun (if it ever shines).

Boogered if I know - I was asleep! At 6am there was frosty leaves at about a metre above ground level upwards.
All the leaves on mine are blackened apart from the new green ones which continue to emerge from the growing point.

 

I know it sounds like the wrong way round but it was more likely to have been a ground frost, trendy name for it a "grass frost".
Temp above freezing, but frost forms on cars etc. and of course leaves, often more on horizontal ones rather than vertical ones
Lower leaves tend to get just that little bit of protection from the ones above.

 

Many thanks LongK and Pete for your very useful comments.

LongK - re-reading the original HTUK conversation I saw that you were a participant. By the way that OBG looks well worth a visit - you have shown lots of nice things there. Its a shame its such a long way from Harrogate.

Pete - if that picture is of yours - its superb. You have answered my main question by talking about cutting the stem down. My original thought was that it was a tree, and like a tree if you cut through the trunk you have a good chance of killing it. But reading a bit further it seems that it can also be a bush - ie springs relatively freely from lower down.

Looking today, curiously my one inside has now lost most of its leaves - perhaps I let it get very dry. But my ones outside haven't lost any leaves yet in spite of having one night of -0.5C a couple of weeks ago. Mind you its been very wet outside - so quite different from the inside one. So I think I must dig them up quickly whilst they still have leaves to dry them off.

 

I've had these flower within one or two years from seed in the past but my current plant hasn't flowered yet, its now 3 years old. Last year it reached 8ft tall and developed flower buds in September that didn't open in the end. This year the re-growth got to around 5ft but it was more bushy, no flowers again though.

I usually keep mine dry over winter, wrap the pot in bubble wrap and the lower 1ft of the stem which is now quite thick is wrapped in fleece with some straw around the base too. Its then kept in an unheated greenhouse, this has always worked for me and I've had no problems with them starting back into growth in the spring and then I cut back the stems to remove the die-back

 

Must admit I'm tending to think that mine are not flowering because they are pot bound.
I cant really go for bigger pots as moving them under cover would be a problem.

So, I think I may at least plant one outside, next spring, and give it a bit of protection the following winter.

Just need to find the right spot, and most of those are pretty much used up these days.

 

I will try to remember to take a photo of the Erythrina at OBG over the winter @pete . Mine had a three inch trunk (actually it was more like a caudex) when it was planted out.

My OBG set on Flickr. Not complete, but a fair representation.

 

Yes one of mine has more like a caudex, the other one came back from under the ground last year, so its a lot thinner.

 

Lovely photos LongK. I have had a good look. It raises the question of what is the best method of showing photos, outside of GC. The Flickr method is very impressive. Is it possible to do something like that and have a comment, such as a name, underneath

It you cut Erythrina back to the ground, does it come back as a single trunk. I was reading in my "Conservatory Gardener" (thanks for the introduction @Kristen - its a brilliant book) that in the cold it can be cut back and stems will regrow - ie like a bush. But in a warmer climate the entire trunk will survive and presumably act like a deciduous tree.

 

That is my understanding too. I know that some Erythrina will throw up suckers but I'm not sure if E.crista-galli is one of those.
In Brisbane Erythrina x sykesii is considered a weed..............

http://weeds.brisbane.qld.gov.au/weeds/common-coral-tree

Poor sods!!!