I have 5 very large pelargoniums in pots indoors. They range in age from 4 years to 2 1/12 years and they all are the result of cuttings from one plant that I brought home from the cemetery in the fall of 2018. I don't like to prune my plants. I like to let them grow, and I support the stems with a variety of fiberglass sticks and soft pipe cleaners. My plants are upwards of 5 feet tall. Since they've gotten too big and fragile to move, I also haven't been able to re-pot them. So they are all in undersized pots. Because of this I have to water every 1 to 3 days. They've been pretty healthy, with the occasional breakage of a stem. But now all 5 seem to be dying. Many leaves are turning yellow then brown. If they were concentrated at the bottom of the plant I would assume the problem is over-watering. But these are at random locations. Some of the leaves skip turning yellow and just turn crispy brown - often one half of the leaf turns brown, while the other half is still green. Some leaves exhibit interveinal yellowing. I believe this looks like a magnesium deficiency, so I have spritzed the affected leaves with a epsom salt mixture (1/4 tsp in a pint of water), but it had no effect. As for plant food, I never got into organic fertilizing because this is inside my home and I don't want something that smells. So I've been using a product called Miracid and another called Jack's Blossom Booster once a week. I put about a 1/4 tsp of it in a quart of water. I don't have a good pH meter, just one of those cheapy moisture /pH probes made in china. It seems to indicate that the soil has a pH of about 7.5. I don't use tap water on my plants, because I believe it is fluoridated. I buy bottled spring water for my plants. Same brand for years.

Thoughts?

Do you have a photo of the plants?

I'd imagine there could be changes in soil texture over time- does it hold moisture and air as well as it ever did? Could the center be dried out and moisture not getting throughout?

I am of those who think you should stick with a fertilizer in the 3-1-2 ratio and complete micronutrients (not blossom boost). 3-1-2 said to be the ratio at which those are used by healthy plants. Blossom boost said to cause a flush followed by a pause. and you don't want to overload on P.
I think this is well regarded, for example
https://www.amazon.com/dp/B003SUT6VS/
but I use MiracleGro or Vigoro 'blue crystals' for the same NOK and look to have the micronutrients as well.

You must have done a lot right to get them to 5 feet

I don't know much about plant food. The Miracid is a 30-10-10 product, wheras the Blossom Booster is 10-30-20. I rotate their use about 50/50. so I figure that makes for a pretty even balance of the three primary minerals (40-40-30). But I really don't know what Pelargoniums need.

I don't have a good camera. And this time of day, it is very hard to get any good pictures, however I have tried. Attached are a couple older and a few new pictures of the plants. After this morning's plucking of dead leaves I couldn't get any good closeups of the problems. I've been removing 6 - 8 leaves a day from each of these plants for the past 3 weeks. They weren't tiny leaves either. So that might give you an idea how much these plants have defoliated. As I said before, either half of the leaf suddenly turns brown and crispy with a clear demarcation line, or the entire leaf turns brown and crispy. Other leaves exhibit interveinal yellowing before turning entirely yellow and then turning brown. I never see the yellow transition on the leaves that suddenly turn brown. And I'm all over these plants every day, examining them. They just suddenly shrivel up.

I'm sure you can see from the picture that I can't offer my plants much sunlight. I only have a few east and north facing windows. The downstairs windows are obscured by the front porch roof. I turn on the fluorescent and LED lights for them a couple hours after I get up, and for a couple hours after dusk.

I'm 69, in very poor health and live alone. Never planted a flower in my life until 5 years ago, after my mother died. It didn't do well at the cemetery, so I brought it home. "Big Germanium" did very well inside, growing to a huge plant with leaves 6 - 7" in diameter. Then it suddenly died from a very aggressive case of black leg. The stem turned black and all the petioles shrunk to the size of threads...

I presumed the disease was caused by my over watering it. I hate to see living things die, so I took cuttings from the very top and that started my current line of plants. Anyway, having lost "Big Germanium", I'm very wary these days about over-watering. These plants are so root bound it is very hard to insert a probe or my fingers more than 3/8" deep. I water frequently and in small amounts. The Pelargoniums don't seem to have very big or deep roots, so that seems best. However with the plants too big for me to transplant, they need daily watering. I suspect the plants are suffering from a nutritional or pH problem, but reluctant to spend the big bucks for a proper pH meter. I've tried those pH test strips that people use on their lawns, but have not gotten consistent results.

Agree, do NOT spend money on a ph meter.
You've done very, very well getting them this size. I envy your success with them!
Your fertilizer plan is reasonable enough, in my mind. But if those run out, I'd switch to one that is a 3-1-2 ratio. I cannot say that the acid part of Miracid is hurting or neutral or helping them.
One problem may arise and that is, fertilizers are salts in chemical terms and your watering in small amounts may well be leaving salts to build up in the soil. Maybe you should stop the fertilizer for a while.
I cannot offer more advice. I have been trying to grow and winter over a geranium or two for 2 or 3 years with very frustrating failures.

Thank you SallyG. You may be right about the salt buildup. That could account for the crispy dried out leaves. I will try to delay watering longer, and using a bit more water to flush some of the salt out. But as I said before, I have a tendency to overwater and have lost plants that way.

Wow! Those are the most amazing Pels I think I've ever seen! Plant goals.

I don't feel qualified to advise, but had similar thoughts to Sally, about the soil changing &/or "going sour" over time. I wouldn't worry about a few random leaves going brown for no apparent reason on otherwise great looking plants, which even the healthiest plants do in their most preferred conditions.

I'm having a similar situation with a Begonia. It grew so much and it's in such a tiny pot, I believe it just can't grow enough roots to support the size in the dry air in the house. I should have trimmed and/or repotted in the fall, but I got greedy, wanting to keep the size AND skip the repotting.

If you have spots for some more little pots, maybe it's a good time to make some new little starts. If, at some point, you end up with too many for yourself, you can give them to - whoever and pass along the fun. Or you could put them in the ground as summer landscape plants.

purpleinopp said: Wow! Those are the most amazing Pels I think I've ever seen! Plant goals.
I don't feel qualified to advise, but had similar thoughts to Sally, about the soil changing &/or "going sour" over time. I wouldn't worry about a few random leaves going brown for no apparent reason on otherwise great looking plants, which even the healthiest plants do in their most preferred conditions.

I'm having a similar situation with a Begonia. It grew so much and it's in such a tiny pot, I believe it just can't grow enough roots to support the size in the dry air in the house. I should have trimmed and/or repotted in the fall, but I got greedy, wanting to keep the size AND skip the repotting.

Thanks. I believe you are right about the soil, dry air and random leaf death. I don't have any more windows for starting small plants. I'm 69 and not in good health. I lack the strength to re-pot my big plants. I don't have the heart to cut them down drastically. So I will wait on God.

I don't know if it's the cause of the current shedding of leaves, but your fertilizer(s) don't have a complete complement of micronutrients. In any case, it would be best to switch to something does, like Dynagrow.

@Engineeringtech
I'll for you and your plants.
My indoor plants often seem to sense spring coming with no real reason that I can think they should. Are they that sensitive to the couple minutes extra daylight per day, every day? And tiny angle of sun being farther up? And as the weather gets better and indoor heat runs less, it may not be so dry.

Hortica said: I don't know if it's the cause of the current shedding of leaves, but your fertilizer(s) don't have a complete complement of micronutrients. In any case, it would be best to switch to something does, like Dynagrow.

Sorry for the delay in responding. (My health has not been good.) I googled Dyna-Gro and see a lot of different products. Which specific one would you suggest?

sallyg said: @Engineeringtech
I'll for you and your plants........as the weather gets better and indoor heat runs less, it may not be so dry.

z
Thanks Sally. I think you are right about the moisture. Winter is almost over here. I may buy a humidifier for next winter. Also will be experimenting with the plant food.

purpleinopp said: Wow! Those are the most amazing Pels I think I've ever seen! .....If, at some point, you end up with too many for yourself, you can give them to - whoever and pass along the fun. Or you could put them in the ground as summer landscape plants.

Thanks for the complement. I have already given away a bunch of cuttings to people. At some point I need to do a major trimming. I just hope my girls forgive me for it!

Dyna Gro "Grow" should give you good growth and flowering.

Hortica said: Dyna Gro "Grow" should give you good growth and flowering.

Thank you. I will get some..

Is there any gardening product more laden with misinformation and outright confusion than fertilizers?

I do not recommend Dyna Gro products. Any company that makes false statements should not be trusted.

From their website;
Dyna-Gro
Dyna-Gro formulas contain all 17 essential macro and micro mineral elements which plants require for optimal growth. The exclusion of any one mineral element will result in abnormal growth, premature death, and or failure to complete a full life cycle.
https://hydropros.com/collecti...

There are *not* 17 "mineral" nutrients needed for plant growth.

A mineral is "a solid inorganic substance of natural occurrence."
Dictionary.com

Here are the 17 elements which have been proven essential for growth of (at least some) plants:

"The 17 Essential Plant Elements include nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chlorine, iron, manganese, zinc, copper, molybdenum, and nickel. The non-mineral essential plant elements include hydrogen, oxygen, and carbon.
These are either taken up as a gas or water."
https://hortamericas.com/blog/...

There are only 14 essential "mineral" elements. Their claim of having 17 is false.

Plants do not obtain Hydrogen, Oxygen and Carbon from fertilizers. They take them in as water (H2O) and carbon dioxide (CO2) usually. Nitrogen fixing plants can also take in nitrogen gas (N2) from the air. Even if a fertilizer has these elements that's not where the plant obtains them.

Dyna Gro Grow is too high in phosphorus (P) at 7-9-5 . Terrestrial plants take up NPK at ratios more like 3-1-2. With 7% N, the P should be more like 2%. This fertilizer will cause a buildup of phosphorus that will be especially harmful in a potted plant with no place for the excess phosphorus to leach into. It will stunt the plant's growth.

I have had little success finding mixing rates for this product. I found this :
Easy Maintenance: Mix ¼ – ½ tsp. per gallon of water with every watering.
https://www.livelyroot.com/pro....

This may be for the Dyna Gro Foliage Pro, which is 9-3-6. That is a better ratio, equivalent to 3-1-2. If you use a Dyna-Gro product I'd suggest using the Foliage Pro.

Dyna Gro Grow varies a lot in price on Amazon. One site offered 1 quart for $23.99 (=$95.96/gallon!). Another offered 1 gallon for $42.43. Foliage Pro was $15.60 per quart on one site.

In general, liquid fertilizers are not very economic to buy. The analysis is low (only 7-9-5 for this) and it costs extra to ship the water it's diluted with.

I prefer Miracle-Gro All Purpose 25-8-16, a dry soluble granule. It lacks Mg (magnesium) and Ca (calcium), so it is not totally complete.

I suggest that you switch from spring water to either distilled or reverse osmosis. Spring water can vary a lot in pH depending on the source.

Also spring water is often "hard" because of dissolved minerals such as calcium and magnesium. If you're using Miracle-Gro All Purpose that could be a good thing.! But if your fertilizer is complete, those additional minerals could concentrate in the soil to excess levels.

Distilled and reverse osmosis waters are neutral in pH and do not have minerals. We have a small reverse osmosis unit installed under our kitchen sink. It has its own tap. We are on a well so this removes salts (minerals) from the water softener and the well water. We drink it, cook, and water the houseplants. A filter cartridge lasts a long time.

I think your geraniums look amazing! An occasional leaf turning brown and dying is normal especially the old leaves. If you are watering every day I don't think fertilizer is advisable every time. Maybe weekly?

Best wishes for continued successful growing!

Pat

PS I forgot you mentioned Blossom Booster. WAY too high in phosphorus! Stop using it. The idea that plants need higher phosphorus to produce flowers than foliage is a good way to sell a gardener another product. But it's not good for the plants or the soil.

Miracid might be OK instead of All Purpose except that I don't know the pH of the potting mix. I suspect it may be high. Perhaps Miracid would help lower it. I think Miracid is now "Azalea Camellia and Rhododendron Plant Food".
Analysis 30-10-10. That ratio is OK. Low in potassium but acceptable.

@Engineeringtech

Hortaholic said: Is there any gardening product more laden with misinformation and outright confusion than fertilizers?

I do not recommend Dyna Gro products. Any company that makes false statements should not be trusted.

From their website;
Dyna-Gro
Dyna-Gro formulas contain all 17 essential macro and micro mineral elements which plants require for optimal growth. The exclusion of any one mineral element will result in abnormal growth, premature death, and or failure to complete a full life cycle.
https://hydropros.com/collecti...

There are *not* 17 "mineral" nutrients needed for plant growth.

A mineral is "a solid inorganic substance of natural occurrence."
Dictionary.com

Here are the 17 elements which have been proven essential for growth of (at least some) plants:

"The 17 Essential Plant Elements include nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chlorine, iron, manganese, zinc, copper, molybdenum, and nickel. The non-mineral essential plant elements include hydrogen, oxygen, and carbon.
These are either taken up as a gas or water."
https://hortamericas.com/blog/...

There are only 14 essential "mineral" elements. Their claim of having 17 is false.

Plants do not obtain Hydrogen, Oxygen and Carbon from fertilizers. They take them in as water (H2O) and carbon dioxide (CO2) usually. Nitrogen fixing plants can also take in nitrogen gas (N2) from the air. Even if a fertilizer has these elements that's not where the plant obtains them.

Dyna Gro Grow is too high in phosphorus (P) at 7-9-5 . Terrestrial plants take up NPK at ratios more like 3-1-2. With 7% N, the P should be more like 2%. This fertilizer will cause a buildup of phosphorus that will be especially harmful in a potted plant with no place for the excess phosphorus to leach into. It will stunt the plant's growth.

I have had little success finding mixing rates for this product. I found this :
Easy Maintenance: Mix ¼ – ½ tsp. per gallon of water with every watering.
https://www.livelyroot.com/pro....

This may be for the Dyna Gro Foliage Pro, which is 9-3-6. That is a better ratio, equivalent to 3-1-2. If you use a Dyna-Gro product I'd suggest using the Foliage Pro.

Dyna Gro Grow varies a lot in price on Amazon. One site offered 1 quart for $23.99 (=$95.96/gallon!). Another offered 1 gallon for $42.43. Foliage Pro was $15.60 per quart on one site.

In general, liquid fertilizers are not very economic to buy. The analysis is low (only 7-9-5 for this) and it costs extra to ship the water it's diluted with.

I prefer Miracle-Gro All Purpose 25-8-16, a dry soluble granule. It lacks Mg (magnesium) and Ca (calcium), so it is not totally complete.

I suggest that you switch from spring water to either distilled or reverse osmosis. Spring water can vary a lot in pH depending on the source.

Also spring water is often "hard" because of dissolved minerals such as calcium and magnesium. If you're using Miracle-Gro All Purpose that could be a good thing.! But if your fertilizer is complete, those additional minerals could concentrate in the soil to excess levels.

Distilled and reverse osmosis waters are neutral in pH and do not have minerals. We have a small reverse osmosis unit installed under our kitchen sink. It has its own tap. We are on a well so this removes salts (minerals) from the water softener and the well water. We drink it, cook, and water the houseplants. A filter cartridge lasts a long time.

I think your geraniums look amazing! An occasional leaf turning brown and dying is normal especially the old leaves. If you are watering every day I don't think fertilizer is advisable every time. Maybe weekly?

Best wishes for continued successful growing!

Pat

PS I forgot you mentioned Blossom Booster. WAY too high in phosphorus! Stop using it. The idea that plants need higher phosphorus to produce flowers than foliage is a good way to sell a gardener another product. But it's not good for the plants or the soil.

Miracid might be OK instead of All Purpose except that I don't know the pH of the potting mix. I suspect it may be high. Perhaps Miracid would help lower it. I think Miracid is now "Azalea Camellia and Rhododendron Plant Food".
Analysis 30-10-10. That ratio is OK. Low in potassium but acceptable.

Wow.
Do you just do hit pieces?

You should check out Mr. pelargonium on Youtube, he's an expert grower of them. He also goes to pelargonium shows as well.

Your plants are quite impressive in size!

Iochroma said: Wow.
Do you just do hit pieces?

Hey @Iochroma ,

Wow.
😂 Didn't you just do what you're accusing me of doing? You "hit" me and my post(s) with absolutely no justification given for doing so. Have you read all my posts since I joined in 2021?

How does your post contribute to solving the problem being discussed?

I did point out that Dyna-Gro, which is in the business of making fertilizers, either does not know what it's talking about or is misleading its potential customers. Is that a hit? I consider it important information. Do you work for Dyna-Gro?

The main reason for my post was to redirect @Engineeringtech from products that may actually make the situation worse for the geraniums. That's important because of her/his limited ability to rescue the geraniums by potting them in fresh growing mix.

I added sufficient information to support my recommendations for changing the products to be used. Otherwise it's just one person saying "use this" and another saying "use that" with no rationale given.

If you have something useful to contribute, please do.

Pat

Dyna-Gro Grow (their 7-9-5 product) gave me many years of good results with mostly succulents, and their recommended dose for indoor use is about right.

The soil pH in a container (especially after many years) tends to be dominated by the pH of the water input, especially if that water is buffered or contains salts.

Purified (bottled) water comes in various forms but the kind we consume here is alkaline (pH >9) and in fact it is the same pH as our relatively hard tap water (ground water). That is not great for some plants (can't speak for yours). In fact I acidify both our tap water and our purified water before use. You don't need to do that, but be aware that a pH close to neutral (or a bit acidic) will tend to yield better nutrient uptake. To put it another way, you will tend to see better results with a lower dose of nutrients given neutral instead of alkaline water.

You can get pH test strips or better yet a pH test kit with drops at your local pet/aquarium store (I use a product by API) and it should be reliable within the specified range. Low cost, low tech, very useful. Much better for this purpose than a fancy pH meter.