Growth on my hawthorn.

I'm not sure if this is a problem or not. Does any one know what this is on my hawthorn. Is it a problem.

It's a rust, related to cedar-apple rust. You can try spraying with a fungicide now (I use lime sulfur) but amputation at this stage is generally the only "cure." You can help prevent it in the future with preventative spraying with a fungicide in later winter or early spring. 2 or 3 applications a week or so apart.

Keep hawthorn away from Juniperus species.

You are just in the beginning of building up your branches on this young tree, so there is no reason not to cut it off immediately, as far away as possible from the infestation and than spray the tree with diluted lime sulfur! When you do so, cover up the ground surface with plastic so that the stuff those not penetrate the surface. Put the infested plant as far away as possible from your other trees until you are sure it is rust free! Make sure to clean your cutter you used with alcohol or with a small flame, to prevent this stuff from spreading! Look closely at all your other trees for signs of further infestation! Preventive spraying in early and late winter will help these infestations to happen!
Good luck,
Hans van Meer.

Thankyou both for your posts. I will do as you suggest and will keep a look out on my other trees.

One question about using lime slupur. Two actually. What dilution do you use, and do you only use it when the tree is not in leaf.

Mix Lime Sulphur with water at a rate of between 1:25 to 1:50 One teaspoon holds 5ml of lime sulphur so you can add between 2 to 4 teaspoons of lime sulphur to 1/2 litre of water. Keep it off the leaves as it can scorch them, but if you apply it carefully, with a disposable soft bristled brush, there shouldn't be a problem. (Disposable as the bristles will fall apart after a few uses.)

Thanks Kev.

My bottle says 1:40. I use a spray bottle. I apply when the tree needs it, leaves or no -- and I don't usually cover the soil at this dilution.

I've been using a mix of 1:30 for years now and this mix cures and prevents many fungal diseases.

will baddeley wrote:I've been using a mix of 1:30 for years now and this mix cures and prevents many fungal diseases.

Do you spray this on the leaves like Jim does.

Smithy wrote:

will baddeley wrote:I've been using a mix of 1:30 for years now and this mix cures and prevents many fungal diseases.

Do you spray this on the leaves like Jim does.

Yes, no problem! To stop further contamination of the tree you are spraying and for the trees surrounding, you need to spray every part of the tree! But to prevent the freshly sprayed solution from dripping on to your soil surface and penitrates your soil, cover it up with some plastic. For the same reason, during the next couple of days dont spray the foliage when you water!
Cheers,
Hans van Meer.

Hans van Meer. wrote:

Smithy wrote:

will baddeley wrote:I've been using a mix of 1:30 for years now and this mix cures and prevents many fungal diseases.

Do you spray this on the leaves like Jim does.

Yes, no problem! To stop further contamination of the tree you are spraying and for the trees surrounding, you need to spray every part of the tree! But to prevent the freshly sprayed solution from dripping on to your soil surface and penitrates your soil, cover it up with some plastic. For the same reason, during the next couple of days dont spray the foliage when you water!
Cheers,
Hans van Meer.

Thanks Hans
I am getting the full picture now . I just like to know all the details befoe i start spraying things. I have a few fungus problems and have not got on top of it. I will be on it this weekend.

does the lime sulphur have a shelf life as i have a couple of opened bottles that have been in the shed for at least a year.
Thanks Smithy

I've had the same bottle for the last three years and it still works. I drape an old thick towel over the soil and leave until the tree has dried. I tend to spray as buds start to open in the Spring, as a preventative for most fungal diseases but see no reason why it cannot be applied now. Make sure you get in underneath aswell

will baddeley wrote:I've had the same bottle for the last three years and it still works. I drape an old thick towel over the soil and leave until the tree has dried. I tend to spray as buds start to open in the Spring, as a preventative for most fungal diseases but see no reason why it cannot be applied now. Make sure you get in underneath aswell

Thanks Will, Thats a good idea with the towel . I will start spraying now but i will be preventative spraying next year.

Good luck!

Thanks Jim.

Let me clarify two things here: first, if the weather is hot, do not apply lime sulfur. Second, let's remember the life cycle of the cedar-apple rusts (this is cedar-hawthorn rust, of course). One type of spore is produced by junipers and infects rose hosts; the spores produced on the rose host infects junipers. By July, and if it's as hot and dry where you are as it is here, junipers are no longer infective and there's no further worry to the hawthorns. What you need to do is look for the infected junipers and trim off the galls for next year [with cedar apple rust, the galls only last one year, so don't even worry; hawthorn rust galls last a few years, so it's worth getting rid of them; quince rust galls are perennial, so it's totally worth finding and destroying them). So that growth on your hawthorn: cut it off. And if you have juniper bonsai, *they* are the ones in peril from the spores produced on that growth. Watch them carefully next spring and remove any galls. The cedar-apple rust galls are produced on leaf scales, so they can be removed without aesthetic damage to a bonsai; hawthorn rust attacks young twigs, so the risk to the beauty of an infected juniper is much higher and needs to be caught earlier.

Thanks Nina that is very helpful. I will digest this so i understand it fully. Do you have any pics of the galls on junipers.

When immature, a hawthorn rust gall just looks like a bumpy growth; when mature and after a rainstorn, it exudes orange-yellow tentacles that I think you'll know when you see. The cedar-apple gall is showier:

http://plantclinic.cornell.edu/FactSheets/cedar-applerust/cedar-applerust.htm

but this fact sheet has a good picture of the stage on hawthorn.