Trillium 2009

[gote]

Paul,
I have always believed that Iron is locked up at high pH. High pH is what causes clorosis on ericaceae like Rhododendron.
However I do think that you are right that the problem is caused by wrong pH.
Göte

[Magnar]

From my garden this week:

[annew]

I think I will repot a couple into fresh compost and leave the rest to see what happens.

[Regelian]

Paul, Göte,

the pH of the soil does change the availablility of cation elements.  Göte has it correct in memory, the lower the pH, the more available the cations become.  This includes Ca+ (calcium), P+ (phosphorus), K+ (potassium), Fe+ (iron), Zn+ (zinc), Al+ (aluminium), amongst others.  Optimal pH for complete disassociation of the ions is around 5.0 pH, which is quite acid.  For most plants this would create an overdose.  Most plants are adapted to a pH between 6.5 - 7.2, with the exception of the Ericas and Co., which prefer 5.0-6.5.  Many woodland plants do prefer a more acid pH.

Soil pH is a complex issue and the actual composition of the top soil and base ground varying greatly to create specific types of environments.

The Trillium looks chlorotic to me, which does mean a lack of iron.  Solution is to increase the organics in the soil and lower the pH gently.

[annew]

Thanks, Jamie. Maybe a dose of sequestered iron might help?

[Maggi Young]

Maybe a dose of sequestered iron might help?

I'd try that, Ann

[johnw]

Our soils here can be very acidic, especially along the coast. When plants, especially rhodos, experience chlorosis iron never seems to work. More often than not epsom salts (magnesium sulphate) and/or gypsum solves the problem rather quickly; sometimes it is starvation and a shot of lime frees up nutrients - this drives the book-readers totally mad. 

Our remedies may simply be specific to our soils but worth a try if the iron fails.

johnw

[Rodger Whitlock]

Our soils here can be very acidic, especially along the coast. When plants, especially rhodos, experience chlorosis iron never seems to work. More often than not epsom salts (magnesium sulphate) and/or gypsum solves the problem rather quickly; sometimes it is starvation and a shot of lime frees up nutrients - this drives the book-readers totally mad. 

Our remedies may simply be specific to our soils but worth a try if the iron fails.

Rhododendron growers in the Pacific Northwest (on the other side of the North American continent) value dolomite. Winter rains leach all soluble nutrients out of the soils, including both calcium and magnesium. Dolomite corrects both deficiencies at the same time.

The conventional wisdom is that our soils are extremely acid but I am none to sure this is true. But nutrient deficiency there is no question about whatsoever.

Over the last decade, I have also given my entire garden a light feed with epsom salts, following the comment of a soil-knowledgable friend who pointed out how most plant foliage here tends to be yellowish. I can't say with certainty that the extra magnesium has made the difference, but certainly everything in my garden seems to grow better these days than it once did.

[Joakim B]

I know that it is often said that the lack is in iron but it is magnesium in the chlorophyll so I expect that it is lack of magnesium that is the cause. Adding some iron derivates like iron sulphate lowers the the pH and makes magnesium more available if existing in the soil so it works indirectly.
This would explain the results that John is talking about. It may be a complex problem where more ions are involved in but having magnesium is good.
Kind regards
Joakim

[annew]

Thank you everyone for your comments.

[gote]

Allegedly we can combat chlorosis with iron chelates (as afoliar feed) so iron deficiency seems to be a reality. Iron is available nearly everywhere in the soil so to add it to the soil is not the answer to chlorosis. However high pH can lock it up so that some plants cannot take it up via the roots.
Since Calcium and magnesium are soulble especially in low pH, it is quite possible to have too little of them in an acid soil. Relatively small amounts are necessary as nutrients. Large amounts rise the pH to a level where the chlorosis problem may occur.
High pH can also cause magnesium deficiency but it seems to be more rare.
I suggest a visit to
http://extension.usu.edu/forestry/HomeTown/care_treatingIron.htm
and/or to
http://www.oznet.ksu.edu/dp_hfrr/extensn/problems/irnchlor.htm

Göte

[gote]

The luteums I posted in May 13th are now in flower - yes there is a faint lemon scent - this means that the markings on the leaves have faded which is a pity.
Göte

[Guff]

Collected some seed today, and planted them. I washed the seed first, then sowed in a leaf compost bed. I will try to keep the spot moist until fall, maybe some will show in the spring? It has taken two springs for me to see seedlings above ground in the past.

[Regelian]

Neeto, Guff!  I didn't realize the seed had an 'aril'-  probably to aid distribution. 

I brought a couple of Tr. cuneatum back with me from Cape Cod, which were just dormant.  Hope I can get them to establish.  Now that seed is ripening, I expect to get my lot from Kristl soon.  I wouldn't have even tried Trillium, if it hadn't been for all of you on this forum.  My previous failures really put me off.  Thanks, all!

[Stephen Vella]

Just to mention that yes the aril aids its distribution by ants and that wasps will do the same. Last summer I harvested some berrys from some T kurabayashii and placed them on an outdoor table and with amazement watched european wasps tear apart at the berry and fly off with the seed and fleshy fruit, all was gone in minuites. Hungry little buggers!