One thing that I do for my blueberries to lower the ph is grab a couple of five gallon buckets of pine needles from my yard. Then I put them in a metal garbage can and stick my weed eater in the garbage can and shred the needles until they're about half an inch to an inch long. Once that's done I spread a good amount around my plants and let nature do the rest. My blueberries have really perked up the last two years since I started doing this.

I would not say mulch was the "culprit". The function of a mulch is not to affect the soil pH. Based on a soil test to see what pH the soil is, my choice has been to use elemental sulphur.

tj

I had always argued that mulch served two purposes for me, to decrease the soil pH and conserve moisture. I wanted to see what everyone's take was on the ability of decomposing hardwood mulch to acidify the soil. I am considering removing some of the pine mulch from under my pine trees and adding it to some of the more acid-loving plants this spring.

I once had a problem with an acid loving plant because there was some concrete dumpster-dive-prize/planter thingy nearby which was leaching some "stuff" into the soil. When we took the cement stuff away, the plant recovered.

:)

If you search this forum you will find many folks citing university studies on how pine needles have little affect on soil pH. However, this is the first I've heard of other choices of mulch actually raising the pH or, at least, adversely affecting acid lovers. That would be interesting.

tj

There is a myth circulating around that certain types of organic matter will change a soils pH, but there is no research to support that although there is ample research that says that adding any organic matter to soil will not significanly change your soils pH. One study I am familiar with was done by Dr. Abigail Maynard at the UCONN Agricultural Research Station at New Haven, CT that years of amending soils there with Oak leaves and Pine needles did not significantly change the soils pH.
In Illinois you native soil should be slightly acicid, not alkaline, because of the normal amount of rainfall those of us east of the Mississippi get. What did a good, reliable soil test show was your soils pH? What is the humus level in your soil, Rhododendrons grow best in soils well amended with organic matter.

Sounds like the author likes pine mulch.

First question: Your hydrangea seems to thrive? Color of bloom as opposed to color it's supposed to be? And what kind of soil do you have? Rhoddies and azaleas hate two things: wet feet and wind, especially in winter.

As far as the heavy metal content, that's probably smoke to distract you. Yes, under high pH conditions, certain metals contribute to chlorosis, iron being the most significant, manganese and magnesium also contributing, but this is a condition of pH changing the outer shell valence, essentially binding the nutrient to the soil and making it unavailable to the plant.

I often hear people tell me that you can't grow things under (usually oak and pine) trees because of the acidity. You can't grow things under large established trees because they have a root system that makes for unfair competition, not because of pH.

Long term, as in many years and a few or several decades, you'll probably see pH become adjusted slightly. Bottom line, organic mulches (hardwood, pine chips, needles, cocoa shells, peanut hulls, whatever) are better for plants than inorganic (stone). Bark based preferable to wood based because of decomposition time and chemistry (colored mulch is evil).

I have some rhodos and azaleas that seem to have responded well to wood chip mulch made from a mix of shredded hardwood trees and limbs (take this for whatever one person's anecdotal experience is worth). The wood chips were at least a few months old when they were used as mulch.

Soils around here are alkaline. Hydrangeas are pink. Well meaning friends have bought me azaleas and rhodies over the years, they croak when they even see my soil. When I asked a nurseryman how to keep my last rhodie alive, he said to trash it and grow something that likes our alkaline soil.

I have mulched my beds every summer with shredded wood mulch, and fall with mulched leaves, for 25 years. The pH is still 7.3-7.4. I have also been adding my compost for probably 15 years, but soil is still alkaline.

Karen

Karen, Over in Kentucky, Tennessee, and other places around you in SW Ohio, the Rhodoendron family grows wild in the woods because that soil is well endowed with organic matter and is somewhat acidic. Soils east of the
Mississippi River tend, due to the rainfall we get, to be acidic not alkaline. The nurseryman you talked with is wrong. Many people that lived near my daughters when they were in Granville, OH had Rhodendrons growing with no problem getting them to grow and blossom.

Hmm interesting discussions. In the SW suburbs of Chicago, the subdivisions are almost exclusively clay and once the summer droughts come, it is notoriously hard to dig and cultivate. Blue hydrangeas are commonly for sale around here, but I have never seen a 4 year old plant with blue flowers. All of mine are pink and when they are not getting chopped down by my overly obsessive plant-trimming father, the summer droughts wreck havoc on them.

In any case, there are other plants that do well with acidic soil rhodies and azaleas were just a suggestion. I have been to the local woods and the soil is much more acidic and contains more than adequate amounts of organic matter. It is the typical subruban "raped" soil that is so difficult.

What really started this whole thing is we have had water problems on the North side of our house, where I planted a Japanese garden and have mulched it and ammended it with plenty of organic matter (hardwood mulch, cocoa mulch, fallen leaves, you name it). The sumac,hydrangeas, and the Jap. maple and toad lilies are doing wonderful and the soil holds so much water now that spring rains bring water into the 1/2 basement; not standing water but dampness in the area near the fireplace. So, now we ahve to rip out all of the plants, install a drain and slope the soil away from the house. The only problem is that most of the shade-needy plants also want acidic soil and my father and several contractors are convinced that the generous amounts of mulch hold water in and soak it into the house. Get, this, under all that good dirt is about 4-5 inches of riverrock from a very bad initial landscape by my dad. So, the plan is to remove the organic layer and replant all the shrubs into the riverrock layer, which will mean sure death to almost all the shrubs. Any thoughts? I would really like to remove the riverrock, save the organic layer and put it back, but my dad is convinced that the mulch is the culprit. We have moved the mulch away from the brick..about a 18 inches and it seems to have helped with the fall rains, so I was thinking about just thinning the organic layer nearest the house and maybe instal a French -style drain with riverrock on top along the foundation which would involve minimal plant-disturbances and loss.

Sorry for the long post.

kimmsr: Once in a while, you just don't know it all. I live here! You are always telling people to get a soil analysis- I did, and it showed an alkaline pH. What part of this don't you understand?

I have gotten 3 beautiful blue hydrangeas which turned clear pink within a couple of months. My hydrangeas are PINK.

Since you don't seem to believe me, will you believe OSU?
copy & paste this one, direct link to another
http://ohioline.osu.edu/agf-fact/0507.html

Here is a link that might be useful: ohio soil

It is possible that the addition of the mulch has allowed more water to remain in the garden and not run off. There may also have been some elevation change as you developed the garden. Whatever the reason, you need to solve the damp basement problem.

The proposed solution seems quite drastic and expensive. I would be more inclined to find a low spot and make a sump that could be drained with a pump or by hand. This should be something that you can do yourself or with the help of a man servant.

I had a similar situation with a sloping garden that stopped at the road. The pure clay layer underneath the soil backed up the water until it overflowed the curb. Impossible to garden. After some thought and advice, I dug a 5' x 5' x 8" deep sump. This sump was filled with small stones and a 5 gal. pail was set in the stones extending through the soil with a little bit above the surface. The sump was covered with landscape fabric before the soil was replaced. The pail was perforated at the bottom and sides and wrapped with landscape fabric. To keep the bucket in place, a 2' long piece of rebar with a large washer welded to one end was driven through one of the holes in the bottom.

A sump pump or an ice cream pail are used to empty the sump. Not only did it solve the flooding problem, it serves as a water resevoir.

Remember that it is your garden, so do as you want and not as your father or the contractor want. Try an inexpensive solution before spending a lot of money.

Just a final point. Generaly, hardwoods are decideous whereas softwoods are coniferous. Cedar is not considered a hardwood.

Here is a link that might be useful: Sump

That's a viable solution, cowgirl. My son installed something similar in our crawlspace allowing us to quickly disperse excess ground water elsewhere.

Where does one obtain a man servant??

The river rock may be the biggest part of the drainage problem. The difference in soil texture (between it and the "good dirt") usually causes the layer above to need to be saturated before allowing the moisture to pass through it. How thick is the layer of "good dirt" on top of the river rock?

tj

There is clay, with river rock on top, and then soil and decomposed mulch. The river rock is about 4-6 inhes thick and on top of that is about 4 inches of mulch and soil. We have had a few warm spells this winter with lots of rain, and low and behold moving the earth away from the house and extending the gutters another 4 feet has helped tremendously. Also, following the water and digging a shallow trench away from the house seemed to help too!!

Blue hydrangeas will turn pink if they don't have enough aluminum. That can happen if aluminum is low or if aluminum is sufficient but, for whatever reason, the plant doesn't take up enough aluminum to keep its flowers blue. Things that restrict the availability or uptake of the other micronutrients will also affect aluminum levels in the plant. You can increase the level of aluminium around your hydrangeas with aluminum sulfate. One brand name I can think off the top of my head is "True Blue" but there are a bunch of them out there.

The aluminum is only available to plants in acidic soil. Aluminum sulfate acidifies the soil, which is why it can change blossoms color. I.e. the aluminum is able to be used by the plant because the pH has been lowered.

Karen

Here is a link that might be useful: aluminum + soil pH

Right, hence the disclaimer: "Things that restrict the availability or uptake of the other micronutrients will also affect aluminum levels in the plant"
I said you can increase the level of aluminum around your hydrangeas (and I am just a little familiar with the acidifying properties of aluminum sulfate, but I didn't want to get into it). However, sometimes your soil is acidic enough and you're just low on aluminum. Sometimes it's alkaline, or alkaline and low on aluminum. Any any case, aluminum sulfate is a good first step without going into a whole bunch of detail. If all you needed to do in every case was drop the pH, elemental soil sulfur and iron sulfate are both much more effective soil acidifiers if placed in the backfill. But if the aluminum level is depleted (as can happen with any nutrient), even in acidic soils, you have to add it.
(Seems I can't open my yap around here without an argument these days)

squonnk: I didn't put that out there to argue anything, but rather to state what I thought a simple fact. I didn't have any way to know that you are familiar with the concept, now did I? Besides, I'm sure that there are others reading who are not familiar with it.

Really, really not meant as an argument.

BTW, after amending my soil with garden sulfur last spring the first blossoms were a decent blue.Here are the first flowers in spring.
{{gwi:260610}}
In a short time, they started reverting to pink, a couple of dingy pinkish-purple mopheads shown here.

{{gwi:260611}}

I've decided to learn to love pink hydrangeas.

Karen

You're absolutely right Karen.
I was being far too touchy and I apologize.

No, squonnk, I apologize for (unintentionally) offending.

But you are right, sometimes there is far too much arguing. I love this forum, find it so interesting and informative. Really I do try never to be rude, or argumentative and I hope I don't come across that way. I really learn a lot more here than I bring to it, I'm sure.

Karen

There are a lot of variables to your wet basement problem but fixing the grade of the surrounding soil is crucial. It would also be useful to know if the exterior of your foundation has any waterproofing and what shape it is in. In the event that you do any major excavation you should investigate the state of the foundation and make any necessary repairs or improvements while there.
The river rock would be useful to absorb the impact of falling water and as a non-rotting material to put near your house.

Karen, I too decided to keep the pink and white hydrangeas. I just admire pictures of the blue hydrangeas on this site.

Cowgirl, thanks for the suggestions, not sure if the sump will work in this site since this is the main entrance to the garden and I don't think my dad would be up for it (it's his house, my garden since I live in the city).

Plans to get an area re-tuckpointed are underway, as well as the French drain. Gutter extenders and some grading will also help. We are using this as an excuse to re-vamp some of the landscapping that has overgrown some areas, so we are looking forward to it. Junipers, while nice and evergreen, are over done here and are looking to replace them with flowering perrenials. Around the house in full sun, junipers are just too much, so out with them and in with the roses, and clematis!! Finally, we can have the full-sun perrenial border I have always wanted.

Based on my readings, it seems that the decomposing mulch does add organic matter to the soil, but drastic changes in pH are not possible. I was under the impression that decomposing plant matter can acidify the soil, but it seems that only pine needles, and oak leaves can do that.

Since we had a few warm days this weeek I was digging around the house and noticed that some areas were much more "organically fortified" than others, so before our landscape re-design, I plan to get as much mushroom compost, manure, and fallen leaves I can find to enrich all the beds. For the hell of it, I snooped around some of our neighbors landscapping and the soil is like wet cement, at least I can easily get my finger in the soil on our property, so the wood mulch has done something over the 8+ years it has been down. My dad (OCD) likes to pile the mulch on really thick in the front borders and I think that it inhibits the breakdown since there is an area 3" under that looks brand new. I think we are going to just "fluff it up" in the spring instead of getting a truckload, lol.

Thanks to all the suggestions.