Sunburn

This cutting of Imperator was left open to the sun on one of our very hot days. Unfortunately this happens when you leave stems exposed to the hot sun.Although the top of the plant is still growing well eventually it will succumb to the sunburn.

Paul Hains in his book "Growing Roses in Subtropical Climates" has a section on sunburn and many other aspects of roses.

If you go to [You must be registered and logged in to see this link.] you can buy a signed copy of this book on line directly from the man himself. All money made from the sale of this book goes to the Queensland Rose Society.

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From where you live Doug, which direction was this rose facing ?

I think the v was facing NNE with the sun shining directly on it.

A few of mine have had this problem over the years. Especially when the rose weevils have worked hard at defoliation...

I pulled up and potted a newly planted bare rooted this year that was copping it. Was a whisker away from losing it but it has bounced back very well.

When I planted my roses this winter I buried the graft, hoping to avoid this (and any cold damage during winter). But the fruit trees I planted, I just planted them with the graft facing south.

Will that stop this problem? A lot of my new fruit trees are looking burnt, but the roses look great

Well, the leaves are looking burnt, so if we have any more hot weather the stems will probably burn too, now that there are so few leaves.

I'm getting tired of the flowers being burnt!

Hi Sue

With pots I have found the flowers rarely dry out if the water is kept up to them. On the hottest of days if I water the pots 3 during the day it generally keeps the burning of the blooms to a minimum.

SueH wrote:I'm getting tired of the flowers being burnt!  

welcome to my world....

Perhaps John, we should follow Doug's advice about watering 3 x a day. I am wondering if they would get water logged though. I suppose as long as I/we have used a good potting compost, they should be ok. My garden faces north, so I also suppose this doesn't help either!

I don't think they get waterlogged in a pot as the water just sinks to the bottom and runs out....

As long as you don't use soil in the pots they won't be waterlogged. The extra watering will leach the potting mix so you need to fertilise more often.

Ahhhhh! Thank you Doug! I was wondering very my Delbard rose, Grand Siecle, was looking a little peaky! Must feed it/them.

SueH wrote:I'm getting tired of the flowers being burnt!  

Tell me about it!

I have two of some roses planted as on at the front garden and the other at the back garden. The front garden has the full sun. The ones at the front always have the sunburn.

Purely by accident that the Zepherine Drouhin and Rose Gajuard at the front never got the sunburn becuase I was lazy and very mean to give them this large space and tucked them under visteria hosta Big Daddy and so on.

I was soo fed up with sunburn I thought this could be my ticket to have the roses free of sunburn. So I created myself a big task. Since November last year I have been planting taller plants and dwarf fruit tees around the roses to create this dappled shade.

I planted Loquat fruit tree moved 2 of 13 years old 2 meters high Chosias next to the roses and replanted the roses under.  I moved two dwarf nut trees to the front and tucked some roses underneath.

The Loquat is getting the frost bite. Err.. Mmmm... Never mind as long as it is not the rose!

But The rose Gajuard next to it is in buds for a month now The buds seem to grow very very slow looking healthy and don't seem to have any scratch on.

See what happens this summer.

SueH wrote:Perhaps John, we should follow Doug's advice about watering 3 x a day.  I am wondering if they would get water logged though.  I suppose as long as I/we have used a good potting compost, they should be ok.  My garden faces north, so I also suppose this doesn't help either!

I was told that the best time to water the plants after 10.30 pm nearer to 11 pm. 'cose by that time the day would reach its coolest peak and that the plant would have recovered from dehaydration and sweating from heat by then and hence the plants will get the chance to absorb and carry water and the nutrition right to the tip of the plant at the very top and its cells will be able to get fattened till the morning and the the plant would be ready for the same cycle of struggle the next day.

It is like doing the same thing when you avoid waering most of the plants late in the day in freezing winters to avoid the damage to its cells but in the summer wait for the coolest part of the day.

The ideal time is just after the sun has risen.....that is so the water doesn't stay too long on the bush and soil evaporation is not quick.....

neptune wrote:The ideal time is just after the sun has risen.....that is so the water doesn't stay too long on the bush and soil evaporation is not quick.....

I agree with you Neptune. Watering this way eliminates the mildew and other diseases on the roses indeed. The drawback would be to have to water very often.

I can't help thinking that the night watering would be suitable for other plants and not the roses.

Then how do I get round watering mixed planting scheme?

The nurseries here water (automatic timing) early in the morning as well as about 2pm.....

good watering is also dependent on soil drainage....plants don't like swimming pools so drainage needs to be looked at. If your drainage is very poor, then watering late at night does no good to the root system as it sits there .....

It is clay soil in here we are on the Chilterns area.

I have been really careful - touch wood - in planting my roses. Hope nothing happens to them. Lots of roots around to suck the excess of water. I suppose good side of packing the area with lots of plants.

Here when it is over 21 degrees celcius for at least 5 consecious days the soil crack opens!

In this really hot weather I water in the evening so the plants can use the water in the cool for as long as possible. (No overhead watering)
I'll often water the pots after lunch as well.
Our soil is based on granitic sand....

You have been busy Alya! Frost bite! Hmmm..... can well remember that! We don't get heavy frost where I live, in fact only very lightly if at all! You must send some photos of what you've done and then again in your summer, then we can all see how things have panned out!