Powdery Mildew on Lilac - dangerous to Tomatoes?

JRinPA · August 3, 2013

This week I twice pruned a few tomato leaves that had what appeared to be powdery mildew on them.

Yesterday I realized the lilac bush nearby has the same stuff on the leaves, hanging right next to the garden.

Question - I have read "on the internet" that powdery mildew is plant specific, such that it does not spread between plants of different types. If two different plants near each other both have powdery mildew, it is due to the moist shady conditions growing two slightly different fungi.

My mom tells me every lilac bush she can recall gets that stuff on the leaves in late summer...but she has no idea whether it will affect tomatos.

So...any thoughts?

I have been sorely tempted to cut down that lilac just to allow more sunlight and circulation. It has gone untrimmed for some years and is pretty large. It is nice looking in the spring and the cardinals love to perch there.

greene · August 3, 2013

Here is a link to one site which says the powdery mildew specific to lilacs Microsphaera penicullata differs from the one on roses:

http://gardeninginthemud.wordpress.c...ldew-on-lilac/

On another site they recommend a dilute milk spray to eliminate the powdery mildew; it's worth a try before you cut down the beautiful lilac - which is my favorite flower!

RayR · August 3, 2013

A quick search for Powdery Mildew on Lilac shows Microsphaera syringae is the pathogen. It does not effect tomato.

There are more than one species that can infect Tomato, but Odium lycopersicum is the most likely pathogen in the North East.

JRinPA · August 3, 2013

Thank you both.

There is no way I could reach the lilac to treat it with anything...the top must be 15 ft or more. It definitely needs to be trimmed some at the least.

It is reassuring that the specific mildew should not affect the tomatoes. I took some off already, but I guess I will wait to trim the rest this winter.

Doug9345 · August 3, 2013

Now I'm going to have to look at other lilac around here to see if they have mildew on them. I know I've seen it on Lilacs and it doen't seem to hurt them. There are lilacs around here that must be 50 years old.

JRinPA · August 4, 2013

The pictures I posted are not even the bad leaves - many were solid grey. I think I may have noticed it last year...I got a little deja vu when I saw it.

But according to my mom, lilacs always get that and it does not seem to hurt them. It makes sense that they would get mildewy, they well in shade. The one in our yard is growing out of the corner of the yard where two rows of arbor vitae intersect to divide the lots in town. Pretty shady and a windbreak.

I pruned two tomato leaves/clusters a couple days apart that had a similar grey powder, so I was a little worried.

zeroma · August 6, 2013

Quote:

Originally Posted by JRinPA

Thank you both.

There is no way I could reach the lilac to treat it with anything...the top must be 15 ft or more. It definitely needs to be trimmed some at the least.

It is reassuring that the specific mildew should not affect the tomatoes. I took some off already, but I guess I will wait to trim the rest this winter.

You can cut the lilac way of half way and it will come back beautifully. So trim

away to give your maters more light!

August 3, 2013	#1
JRinPA Tomatovillian™ Join Date: Jul 2013 Location: SE PA Posts: 963	Powdery Mildew on Lilac - dangerous to Tomatoes? This week I twice pruned a few tomato leaves that had what appeared to be powdery mildew on them. Yesterday I realized the lilac bush nearby has the same stuff on the leaves, hanging right next to the garden. Question - I have read "on the internet" that powdery mildew is plant specific, such that it does not spread between plants of different types. If two different plants near each other both have powdery mildew, it is due to the moist shady conditions growing two slightly different fungi. My mom tells me every lilac bush she can recall gets that stuff on the leaves in late summer...but she has no idea whether it will affect tomatos. So...any thoughts? I have been sorely tempted to cut down that lilac just to allow more sunlight and circulation. It has gone untrimmed for some years and is pretty large. It is nice looking in the spring and the cardinals love to perch there.

August 3, 2013	#2
greene Tomatovillian™ Join Date: Jul 2013 Location: Savannah, Georgia Posts: 13	Here is a link to one site which says the powdery mildew specific to lilacs Microsphaera penicullata differs from the one on roses: http://gardeninginthemud.wordpress.c...ldew-on-lilac/ On another site they recommend a dilute milk spray to eliminate the powdery mildew; it's worth a try before you cut down the beautiful lilac - which is my favorite flower!

August 3, 2013	#3
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,464	A quick search for Powdery Mildew on Lilac shows Microsphaera syringae is the pathogen. It does not effect tomato. There are more than one species that can infect Tomato, but Odium lycopersicum is the most likely pathogen in the North East.

August 3, 2013	#5
Doug9345 Tomatovillian™ Join Date: Oct 2011 Location: Durhamville,NY Posts: 2,706	Now I'm going to have to look at other lilac around here to see if they have mildew on them. I know I've seen it on Lilacs and it doen't seem to hurt them. There are lilacs around here that must be 50 years old.

August 4, 2013	#6
JRinPA Tomatovillian™ Join Date: Jul 2013 Location: SE PA Posts: 963	The pictures I posted are not even the bad leaves - many were solid grey. I think I may have noticed it last year...I got a little deja vu when I saw it. But according to my mom, lilacs always get that and it does not seem to hurt them. It makes sense that they would get mildewy, they well in shade. The one in our yard is growing out of the corner of the yard where two rows of arbor vitae intersect to divide the lots in town. Pretty shady and a windbreak. I pruned two tomato leaves/clusters a couple days apart that had a similar grey powder, so I was a little worried.