millerrocks
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Hydrangea in bed with lime rocks

Hello,

During late spring, a little over 2 months ago, we planted 6 hydrangeas (3 on each side) in the empty flower beds on the front of the house. To cut down on weeds, instead of filling the flower beds with soil, we filled them with white lime rock.

I have read that lime works against the acidic level of the soil making it impossible for the Hydrangeas to change color, which is okay at the end of the day.
I am a bit concerned with the progress they have made. They were labeled as FAST GROWERS but they have not grown very much. I have also noticed a change in the leaf color, from deep green to a lime green. They have had a few blooms here and there, they don't wilt in the summer heat here in zone 9, south of Houston TX. I water them deeply about every 3 days. I purchased them from Lowes as FOREVER AND EVER hydrangeas, the two flanking the outter sides were Foil gifts for Mothers day. One is doing well with no new blooms, while the other is completely fried. I am considering of pulling out the ones flanking the ends and replacing with a creptmertlyes to give them more shade at noon. The front of the house gets good hot sun from about 7 am - 1:30pm and filtered light for the rest of the day.

What is your opinion on the wellfair of my plants? I don't know if being planted around lime rock is stunting their growth, or turning the leaves lime green. Also how much can I expect for them to grow? I can't see them from the road infront of my home.

Thanks for your opinions and help!


right side
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0093.jpg[/img]
[/img]

Left side
[img]https://i76.photobucket.com/albums/j26/BullMiller/samsungintercept2173.jpg[/img]

[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0083.jpg[/img]
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0084.jpg[/img]
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0089.jpg[/img]
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0091.jpg[/img]

the two foil plants flanking the ends are having a hard time. The fried one gets after noon sun from a brake in the trees hovering over my roof on the right side. Underneath the fried leaves there are however new leaf buds. I do not think these will bloom anymore this year.
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0086.jpg[/img]
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0092.jpg[/img]

luis_pr
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Location: Hurst, TX USA Zone 7b/8a

Hydrangeas like acidic soil and tolerate s-o-m-e alkalinity. The lime in the rocks will bleach out and make the soil more alkaline. As long as the process does not release too much lime, the hydrangeas will ignore but if it becomes too alkaline, the leaves will turn lighter green or yellowish, with the leaf veins remaining dark green. Photos 3 and 6 appear to have some leaves near the top exhibiting this.

If the leaves start turning light green or yellowish, without the leaf veins remaining dark green, the plants could be getting too much. Linke in picture number 4 and maybe 5 (not clear/close enough).

As a way of comparing, here in the Dallas / Fort Worth Area, sunrise happens at 6:30am and I let hydrangeas get sun until 11am to 12pm. If I expose them to more, the leaves sunscorch.

While hydrangeas can be fast growers, every now and then you find one that is not. I have a Glowing Embers that is growing nicely but slowly. I expected it to be much bigger by now but -oh well- it happens. The size specificied on the plant label is the expected size at maturity, a commercial term that basically means in 10 years. So your shrubs still have time.

Obtain a soil pH Kit sold at many plant nurseries so you can monitor the soil pH with some regularity. If the kit indicates that the soil is too alkaline, you can acidify it using garden sulphur, iron sulfate, aluminum sulfate, green sand or iron-chelated acidifying liquids. Then monitor the soil so you do not have wet soil -which causes root rot- or periods of irregular soil moisture (the soil gets dry then wet then dry, etc). Aim for "constantly moist" soil instead. Mulch with 3-4" of mulch up to the drip line.

Also, do not fertilize stressed plants. These guys probably have fertilizer pellets in the potting soil mix so next April, add 1/2 to 1 cup of compost, composted manure or cottonseed meal; repeat the application again in June.

Just wondering, have you had a soil test done before?

millerrocks
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Joined: Tue Jul 12, 2011 4:05 pm

Hello, thank you for replying.

I have not tested the soil before. But the soil in the flower bed was always nice and soft, it is a mixture of soil and sand. Before I planted them in the hole, I filled it with water to make sure it had good drainage and it did. It drained in a matter of seconds.

A few concerns jump up at me after reading your most helpful post. Are my hydrangeas in danger of dying if the alkaline levels are too high? Will it stunt their growth/flowering?

I would like to say in more detail that only the top layer is white lime rock. I first filled the depth of the flower bed with the beige gravel rock you see fill potholes on driveways. I wonder if the top layer of lime would be enough to affect the plants. I usually water directly on the base of the plants and soak them for a good 15-20 minutes a few times a week. (DARN: just read up on what a drip line is and it says not to water the base of a tree because it gets root rot, I am going to cry).
The rest of the rock doesn't really get wet unless it rains, which it hasn't in this area. There is a burn ban in effect.

I am not feeling optimistic about their success now, boohoo :,(

I can take closer pictures of the leaves for you tomorrow in the morning. Thanks a bunch for your help

luis_pr
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Location: Hurst, TX USA Zone 7b/8a

Question: Are my hydrangeas in danger of dying if the alkaline levels are too high? Will it stunt their growth/flowering?

Answer: In high enough levels, it can stunt growth. Signs of iron chlorosis on the leaves in some pictures suggests that levels are rising. Again, you could control high levels with some of the things I suggested. And obviously, you could also take out the lime rocks as well.

Watering: about a gallon of water per watering will do for these newly planted shrubs.

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rainbowgardener
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Luis is our acknowledged hydrangea expert and very knowledgeable, so I'm not trying to add or change anything he said. But millerrocks, as I read your two descriptions, I'm hearing about gravel and limestone, but I'm not hearing much about soil. Is the only soil the little circle they are growing in?

Plants can't grow in rock. If you want to have a good sized shrub, it needs a good sized amount of soil. If that bed is not mostly soil/ dirt, I would take all the rocks out, fill it with soil and put a layer of wood chips down on top for mulch/ weed suppression. Even if you have to pull a couple weeds now and then, that is better than killing the shrubs you spent money on.

millerrocks
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Here are a few close up pictures
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0095.jpg[/img]
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0096.jpg[/img]
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0097.jpg[/img]
[img]https://i76.photobucket.com/albums/j26/BullMiller/IMAG0098.jpg[/img]

millerrocks
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rainbowgardener wrote:Luis is our acknowledged hydrangea expert and very knowledgeable, so I'm not trying to add or change anything he said. But millerrocks, as I read your two descriptions, I'm hearing about gravel and limestone, but I'm not hearing much about soil. Is the only soil the little circle they are growing in?

Plants can't grow in rock. If you want to have a good sized shrub, it needs a good sized amount of soil. If that bed is not mostly soil/ dirt, I would take all the rocks out, fill it with soil and put a layer of wood chips down on top for mulch/ weed suppression. Even if you have to pull a couple weeds now and then, that is better than killing the shrubs you spent money on.
Hello Rainbowgaredener thank you for chimming in. I need all the opinions I can get. :) If you look back to pictures 1 & 2 you will see that there are two rows of landscaping bricks lining the flowerbeds. There is soil filled up to the top of the bottom brick then gravel rock filling in the rest to the top brick. so about 6 inches of dirt and then 6 inches of gravel. I dug the holes twice the width of the pots, and a little deeper but filled it(and watered it to settle the soil) with potting soil to level the pot with ground level. Then we carfully filled in the outside space with the gravel around the plants. Lastly we encircled the hydrangeas with mulch.

I have never tested soil before but when we moved in there was a few crazy looking rose bushes and a variety of other unlabled plants growing there. The soil was never tough or clayish. We also planted 2 palm trees on either side of the house and had to dig about 4 foot holes and we didn't run into very much clay. The ground was soft and easy to dig out. It was a mixer of sand and soil.

Do you think they wont do well? The gravel was a last minute idea and I didn't research the lime rock affecting the hydrangeas until after we were done with everything. :(

millerrocks
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luis_pr wrote:Question: Are my hydrangeas in danger of dying if the alkaline levels are too high? Will it stunt their growth/flowering?

Answer: In high enough levels, it can stunt growth. Signs of iron chlorosis on the leaves in some pictures suggests that levels are rising. Again, you could control high levels with some of the things I suggested. And obviously, you could also take out the lime rocks as well.

Watering: about a gallon of water per watering will do for these newly planted shrubs.
Mr. Luis,

If I decide to add more sulfur to the ground, should I consentrate on the drip line of the hydrangeas (which would be the mulched areas surrounding them right?) or should I add it to the entire bed? I have a couple bags of sulfur I bought to change the color from pink to blue, but they are little rocks/pellets, how do I get these into the ground under the gravel? I am sorry that I am inexperianced in all of this. Should I mix the pellets in water and then apply?

Thank you

luis_pr
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Hello, millerrocks. Garden sulphur comes in various forms and its application should be done based on the label instructions (how much and how often) as these vary.

It should be applied around the shrubs starting near the rootball and moving outwards in all directions. You can stop broadcasting it once you get about 3-6 inches past the drip line. The recommended approach is to remove the mulch; water 1/2 gallon (on a new shrub); apply the sulphur per label directions; water again (same amount); and replace the mulch. It is usually not necessary to mix it in with the existing soil.

Do not over apply or apply it more often than recommended because it can cause root burn. Some of the hydrangea roots are fibruous and can burn if given too much sulphur.

millerrocks
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luis_pr wrote:Hello, millerrocks. Garden sulphur comes in various forms and its application should be done based on the label instructions (how much and how often) as these vary.

It should be applied around the shrubs starting near the rootball and moving outwards in all directions. You can stop broadcasting it once you get about 3-6 inches past the drip line. The recommended approach is to remove the mulch; water 1/2 gallon (on a new shrub); apply the sulphur per label directions; water again (same amount); and replace the mulch. It is usually not necessary to mix it in with the existing soil.

Do not over apply or apply it more often than recommended because it can cause root burn. Some of the hydrangea roots are fibruous and can burn if given too much sulphur.
Thank you very much for all your help Luis. I will purchase a soil testing kit and do whats nessasary. I will be looking forward to coming back to update the forum.
Best Regards

luis_pr
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You're welcome. By the way, I just noticed your "new" close up pictures today.

Photos 1 and 4: Iron Chlorosis; observe how the leaves are turning light green to yellowish. Observe also how the leaf veins remain dark green. This indicates that the plant is unable to absorb iron and has a mineral defficiency called "iron chlorosis". The reason for the problem is that the soil pH is too high. Hydrangeas like acidic soils but tolerate some alkalinity. But when this alkalinity gets "bothersome" then they display these symptoms. Add some soil acidifiers like garden sulphur, green sand, iron sulfate, aluminum sulfate or iron-chelated liquid products like Green Light's Iron & Soil Acidifier. The liquid products allow you to acidify the soil faster although you probably have to apply it several times (until the leaves look dark green all around).

https://www.greenlightco.com/products/ironandsoilacidifier/

Photos 2 and 3: Sunscorch (too much sun). Observe how the leaves are turning yellowish. Notice too that the leaf veins are not staying dark green. The shrub needs protection from the sun or it needs to be transplanted elsewhere.

Photo 4: the leaves have developed a fungal infection. This could simply be an opportunistic infection made possible by the heat/sun stress and maybe some overhead watering. You could cut them off or leave them there but if you leave them there, dispose of them in the trash when they eventually dry out during winter. They are loaded with spores and will infect the other shrubs, if they have not done that already. You could also spray fungicides but I am not sure if it would be cost effective this late in the growing season.

millerrocks
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luis_pr wrote:You're welcome. By the way, I just noticed your "new" close up pictures today.

Photos 1 and 4: Iron Chlorosis; observe how the leaves are turning light green to yellowish. Observe also how the leaf veins remain dark green. This indicates that the plant is unable to absorb iron and has a mineral defficiency called "iron chlorosis". The reason for the problem is that the soil pH is too high. Hydrangeas like acidic soils but tolerate some alkalinity. But when this alkalinity gets "bothersome" then they display these symptoms. Add some soil acidifiers like garden sulphur, green sand, iron sulfate, aluminum sulfate or iron-chelated liquid products like Green Light's Iron & Soil Acidifier. The liquid products allow you to acidify the soil faster although you probably have to apply it several times (until the leaves look dark green all around).

https://www.greenlightco.com/products/ironandsoilacidifier/

Photos 2 and 3: Sunscorch (too much sun). Observe how the leaves are turning yellowish. Notice too that the leaf veins are not staying dark green. The shrub needs protection from the sun or it needs to be transplanted elsewhere.

Photo 4: the leaves have developed a fungal infection. This could simply be an opportunistic infection made possible by the heat/sun stress and maybe some overhead watering. You could cut them off or leave them there but if you leave them there, dispose of them in the trash when they eventually dry out during winter. They are loaded with spores and will infect the other shrubs, if they have not done that already. You could also spray fungicides but I am not sure if it would be cost effective this late in the growing season.
I am glad I came back to check and saw you had given me more insight. I am in the process of buying the soil testing kit and hunting down the liquid sulfur to apply asap. I am sure the soil test will say its too alkaline from everything you have told me. But I am glad that it's something I can change to help them be healthy. I sure hope it helps because it was a lot of work to clean the bed and plant the hydrangeas then shovel in that rock etc. I dream of having beautiful hydrangea bushes greeting my front door. I hope my dream isnt impossible.

I will remove those infected leaves and dispose of the like you suggested. I am planning of pulling out the 2 flanking the ends and replacing them with crept myrtle tress to give them more shade.

I will continue to update. Thank you again for all yourknowlegde & :D help.

Moley
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Location: Brooklyn NY

I use Green Light's Iron & Soil Acidifier on my blueberries, rhodies and hydrangeas, got it on Amazon.com for $10, works very well.

luis_pr
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Location: Hurst, TX USA Zone 7b/8a

It also a NPK Ratio of 0-0-0 so it will not trigger growth in places like mine where winters are very mild and applying liquids with nitrogen might wake the hydrangeas. Becase of temperature swings, I always kid that hydrangeas here do not sleep well. That they probably sleep as well as someone sleeping besides a snorer. :lol:



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