'Endless Summer' hydrangea /Quest for BLUE blooms

Has anyone who has planted 'Endless Summer' hydrangea in areas with alkaline soil been able to keep the blooms blue after the first year? I know about the soil treatments, and have tried a few different approaches with sulfur, etc. with absolutely no success (after three years). I'm wondering if gardeners should just plan to dig an extra large hole and use composted peat moss/regular peat moss alone to completely fill in around a new plant. Any ideas out there?

Are you repeating your amendments every year? Your pH will tend to go back up if you don't amend on a regular basis. Also have you checked your soil pH after you do the amendments? Depending on how alkaline your soil was to begin with you might not have been adding enough to drop the pH. But if your soil is that alkaline I'd either learn to love pink flowers or else grow them in a container where it'll be easier to control the pH.

What is the pH? Dirr says to use aluminum sulphate. I'm assuming that hasn't worked either?

I was recently talking with someone who knew of someone (you know how that goes) that sprayed the blooms themselves with an acidifying agent. If only half of the bloom cluster was sprayed, only that half would be blue. Sorry, that's all I know - but it is an interesting thought . . .

Hoosier, If your soil is very sandy, there is no problem with digging out a large hole and replacing the soil with composted peat moss and peat moss. However, if your soil has a high clay content, you will have created a big bath tub for your hydrangea to drown in. Hydrangeas like well draining soil. You've received good information. A pH meter is essential and you must repeat applications to keep the soil acidic.

Yep. I repeated the applications for two years. Tried sulfur, aluminum and organic fertilizer for acid-loving plants, etc. with no luck. The places they've been growing in are originally very clay-based, but over the years, the soil has been either replaced or amended so much that it's just wonderful loamy soil. So, I think I can avoid that bathtub affect. I do enjoy the heavy bloom that I'm getting, but oh, for blue, blue, blue! I think that this fall, I'm going to remove as much of the soil around the established plants as I can and just heap in composted peat moss, then mulch with regular peat moss and pine needles. Maybe next year? (That idea from Leftwood about spraying the blooms sounds intriguing! I wonder what was used?)

There's no such thing as a spray on acidifying agent product to make hydrangeas turn blue (or pink for that matter, either). Would that there was !
The color is determined by the pH of the soil.

Changing the pH of soil isn't something that happens overnight, but it can be done...gradually...and, as stated above, must be maintained to keep it at that level for the desired color you want.

I have alkaline sandy clay soil but have successfully grown blue hydrangeas by planting them in solid peat moss. They remained blue for three or four years and eventually started becoming pink again due to my not adding aluminum sulphate to the soil.

I resumed the application last year and the pH is now slowly changing.
Last year, a few were a very deep lavender instead of pink, so it's a slow process. It's mostly an experimental project at this point.

A very simplified way to illustrate changing the pH of soil (without getting super technical about it) is this:

If you have black hair, you can bleach it and add dye to it to make it blonde.
But, when your hair grows out it's still going to be black. (Or vice-versa)
The bleach and dye is a tempoary change.

The same principile applies to the soil. Eventually it's going to revert back to it's native pH unless you continue to add the appropriate elements to keep it at the level you want.

Great news, JasperDale. I thought that planting in pure peat moss would work, but it's good to know that I should still continue to apply aluminum sulfate to keep it acid. This I will do. I wonder if I should just dig up the hydrangeas next spring (or this fall?) and replant them in peat, rather than dig out the soil all around them to replace with peat. Maybe I'll do a few each way. Regardless, I'll post how it works out. Thanks.

Here is what Dirr says about flower color in his " Hydrangeas For American Gardens" pp 174 -175

" Blue or pink colors are predicated on the amount of aluminum in the soil in solution which can be absorbed by the roots. Although pH is often listed as the agent of color change, it is actually an instigator of ( a precurser to) the process. If soils are acid, aluminum is available; if more alkaline then aluminum is tied up in insoluable forms and not readily available fo uptake. So, the story is true that high acidity, i.e., low pH, solubilizes ( or makes available) aluminum; the reverse occurs at low acidity ( high alkalinity ). i.e. high pH. Excess phosphorus in the soil will also tie up the aluminum in insoluable precipitates, even in acid aoils. Hydrangea macrophylla grown in pine bark medium, pH 5 to 6 are typically pink. Why? The acidity is high, but almost no aluminum is present in the substrate ( bark). Soil is composed of minerals, typically aluminum, silicon. iron etc,, and therein resides the difference. So how do growers produce blue hydrangeas in pine bark? Aluminum sulfate is added to the surface of the container ata prescribed rate, usually 0.75 to 1.5 ounces evenly distributed on the surface of the 3-gallon container medium. Greenhouse growers also apply it as a drench at the rate of 2.4 ounces per gallon solution with 8 ounces applied as a drench pre 6 inch container. Greenhouse treatments start at budbreak and continue every two weeks for three additional applications. Growers have variable timetables for applications but in our work as soon aa flower buds are visible, a single application at the 1.5 ounce rate per 3-gallon is made. Water thoroughly after application to ensure solubilization of the aluminum and movement into the root zone. Too much is worse than too little: I have dwarfed and killed plants with excessive applications. Hydrangea macrophylla displays a high tolerance to aluminum. Research ( Ma et al. 1997, Ma 2000) showed that aluminum complexes with citric acid in the cell sap and may be detoxified in this manner.

Occaisionally, elemental sulfur ( flowers of sulfur) is recommended for acidifiying the soil and thus mobilizing (solubilizing) aluminum. This is a boderline crazy approach and slow to effect the desired change. If the soil pH is high live with pink, rose, and red hydrangeas--they are beautiful-- or create raised beds, laden with acid organic matter. and apply aluminum sulfate that over time will lower pH and supply aluminum for ready blueing,. Hydrangea macrophylla or H. serrata, in any shade of pink to red is satisfying. Consider nature's gift to the garden, accept and enjoy. On the other hand if soils are acid as lemons. lime may be added to raise the pH if pink, rose and red flowers are desired."

I'm not the best and fastet typist in the world. There may be typing errors.

This message was edited Sep 11, 2008 11:51 AM

So, if I understand this last entry, I'll still need to add aluminum to the soil mix, even if I plant in almost total peat moss. Makes sense, since there would be few minerals in peat moss, I think. Maybe it would work best to mix in an organic fertilizer designed for acid-loving plants, like Holly Tone.

That was my take on what Dirr was saying. But about using sulfur to acidify soil I have a different experience from what Dirr reports. I have the Endless Summer planted in with Enkianthus. The Enkianthus needs truly acid soil but they would not like an accumulation of aluminum. My soil is just below neutral - 6.5 to 6.7. If left alone Endless Summer blooms a light violet. I now add ground sulfur every late fall to keep the Enkianthus happy and the adjacent Endless Summer blooms that beautiful blue. So I must have enough aluminum present in the soil which does become available when the pH is lowered.

Holly Tone is a good organic fertilizer. I use it for the Rhodies and the Enkianthus. I get a better bud set though if I apply Scotts' for Rhodies once in the spring and SulPoMag in mid July.

http://www.basic-info-4-organic-fertilizers.com/sulpomag.html
http://www.amazon.com/s?ie=UTF8&keywords=sul%20po%20mag&search-type=ss&index=garden

Soils are so, well, territorial. You think you know what you have and then you get a real surprise.

Michale Dirr's hydrangea book is just chock full of stuff that makes gardening with hydrangeas a lot more understandable.

I wouldn't fight the PH level, it's a losing battle.

Actually leftwood, I think it depends on the soil. I do use ground sulfur to get blue hydrangeas and it works in the year I apply it. If I forget to apply in the fall, and I'm reminded in the spring because the first blooms appear mauve or light purple, an application of sulfur will correct it in the same growing season, and subsequent blooms in that season will be blue. If I apply in the late fall, the blooms next season are blue right out of the gate. I use Espoma Garden Sulfur - 90%.

My experience seems to directly contradict Dirr's. I did check my accuracy of using the word "and" in the quote to which you refer. I did type it correctly.

This fall I'm sending in soil samples for testing. (It's been about 4 years since I last had it done.) The hydrangea - enkianthus bed will get a test. I'm more curious now than ever as to the aluminum content of the soil because I have never used aluminum sulfate in this bed. In fact I have never used it anywhere as I have a lot of plants in the Ericaceae family that would not tolerate an accumulation of aluminum at their roots.

Soils here can vary within a few feet going from a sand dune, which I have, and to swamp soil, which my neighbor has. Under the sand here is a water impermeable clay layer located anywhere from a few inches under the sand to 20 feet! Makes gardening here extremely interesting!


This message was edited Sep 12, 2008 12:00 PM

Right, Snapple. Soil is a huge factor that dictates how fast a pH change can be done. Clay soils, especially high pH clay (Lol, is there any other?) would take the longest.

I am surprise at the rapidity of your pH change. This is with flakes of sulfur, right? (ground sulfur [meaning soil sulfur] or ground sulfur [meaning ground up sulfur]?) A powdered form would be easily understandable. For the benefit of others, and correct me if I am wrong Snapple, but I believe your needed pH change would be minimal in an area where it was previously the desired level just the season before. This is in contrast from most gardeners, where at least at the time of the initial application, radical change must occur. Indeed, the rate of change should not waver, all other things being equal, but it is the amount of change in question.

Your challenge with adjacent soil types is a blessing as well as a pain. A key, I think, is to know exactly what you're dealing with.

This message was edited Sep 12, 2008 12:15 PM

The Espoma sulfur form is not ground powder but tiny pellets. They dissappear into the soil after about two good rains.
http://www.espoma.com/pdf/garden/GI_31.pdf

The soil is well amended sand (peat and composted oak leaves) and the natural Ph doesn't need much of a nudge. Sulfur absolutely works faster on sandy soil. Rhododendrons grow extremely well here with no Ph change necessary, if you can keep any moisture in the sand! But to keep the Enkianthus happy I try to drop the Ph to at least 6, a drop of about .05 to about. 07. Not much really. I use only sulfur.

BTW an outstanding Enkianths campanulatus is Furin Tsutsuji (Greer Gardens). It has four season interest. In spring the shrub produces large clusters of small pure deep pink nodding bell shaped flowers. The tiered/ layered branching structure stands out from all other shrubs in summer. In fall the leaves are among the showiest of intense reds and golds. Then again in winter the layered branching structure is very notable, especially when it captures and holds snow. They are rock hardy zone 4. Well drained acid soil and regular moisture are all they require.

This message was edited Sep 12, 2008 2:28 PM

Ah. So your sulfur does assimilate rather quickly. A year later, I can still easily see flakes of sulfur in the soil.

I didn't know Enkianthus liked such acid soil. And thanks for the tip on the cultivar. You never know when it will come in handy . . .

I planted an 'Endless Summer' hydrangea last year at about this time. I was convinced that it did not make it through the winter but it did. I added aluminum sulphate in the soil around the plant following the directions on the package earlier this year when it was evident the plant was indeed alive and thriving. The first blooms followed about a month later and were greenish/white. I reapplied (about two months after the first growth emerged, which was when I applied the first time), doubling the dosage and BURNED THE HECK out of the plant. I had a lot of dieback, though what lived was blue for about two months. Now there are a few new blooms that are all greenish/white again. The plant seems to be improving now, but was not happy with the amendment. It was remarkable how quickly it burned and then how quickly the blooms reverted in color. It was never that great blue that it was when I planted it last year.

My hydrangea is planted in an area with well draining soil, what I would consider to be "pretty good" for gardening.

Elizabeth

I'll be darned. It sure "isn't one size fits all" in the amendment department when it comes to coaxing out blue in a hydrangea. What does surprise me is that your blooms are greenish white to begin with. I had thought that the normal color of Endless Summer in neutral or alkaline soil was always pink, with the pink shading to purple and then to blue as the pH drops.

Mine is planted in what I would consider "medium dappled shade" - would that have anything to do with the greenish/white color? It definitely was never pink! The color was great, a rich blue, last year when I bought it at the end of the season on sale from a reputable local nursery. It was a large mature plant, well established. I thought I had killed it when I did the second application of aluminum sulphate this year, but it seems to be making a comeback. The flowers are definitely greeninsh/white again, though. I'm sure sale season is coming up again, I might buy another and plant it fifteen feet or so from this one to see if there is any difference. One of my little conifers died and I need something to replace it with, I think the area is probably perfect for another hydrangea.

Is it possible that a customer had put the wrong plant tag back in the pot? It wouldn't be the first time.

Because I have Enkianthus ( which will not tolerate excess aluminum) in the same bed I dont use aluminum sulfate. I use soil sulfur to lower the pH and make the aluminum already in the soil available. According to Dirr, that's not supposed to work too well. But for me it does.

It would not be possible with mine - it had one of those clunker tags that are hard to remove, and the pot itself was labelled. Driving to work today I saw that the nursery stock is 25-50% off, I'll try to make a trip out there soon, though I know that if I wait until October 1, nearly everything will be 75% off!

Ah, fall and 50%-75% off. Makes fall a welcome season! I' waiting to pick up some hostas and replace a 'Pimoko' spruce. I hadn't better wait too long on the latter however.

I saw this yesterday morning and the phosphorus thing stuck in my head. I am going to try it.
http://www.hgtv.com/landscaping/hydrangeas/index.html


Susan

ic - I checked my two hydrangea references ( Dirr and VanGelderen) re: endless summer.
Dirr does not mention any specifity of color. He does list it as one of the "Best of the Best". VanGelderen says bloom color is pink to blue ( which is what I experience). Yesterday I was prowling around a local garden center when I spied a mop head with greenish white blooms. It was labeled "Endless Summer" and there was absolutely no confusion as to the labeling. So - go figure!

snapple45: I've seen labels that say 'Endless Summer', then also 'Blushing Bride', which is a newer variety with "sparkling" white blossoms, but the same ability to bloom on new wood. It can be confusing! Usually, if the original 'Endless Summer' is sold in a blue pot, and the 'Blushing Bride' in a black or white pot. What color was the one you saw?

The pot was definitely blue. I'm thoroughly confused.

Just to add to the confusion, I saw 1 gallon Hydrangeas at Home Depot yesterday labeled "Forever Summer". They were a mauve color...but the wording on the label said, "lavender"

They were all the same color in the display.
Again, as was said above, Go Figure !

I know the word "mauve" means a different color to different people.