Almost all of the blueberry plants I brought from the store have time release fertilizer capsule in them. Was wondering if anyone know which product I can use that is safe and effective for blueberries in container? Thanks!
Here are some ideas: Slow Release Fertilizer For Acid Loving Plants - Justagric
I’ve used an acidic slow release from Osmocote on blueberry.
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Thanks! Do you know where online I can get ahold of the osmocote slow release for acid plants? Have no luck finding it. I have so many smaller blueberry cuttings that I am growing out and it’s just less of a hassle using some type of slow release fertilizer.
Walmart sells this for under $6…
https://www.walmart.com/ip/Expert-Gardener-Azalea-Camellia-Rhododendron-Plant-Food-Fertilizer-10-8-8-3-lb/602985638
It looks like that Walmart stuff gets it’s Potassium from Muriate of Potash or Potassium Chloride.I’m not sure if @fruitnut remembers bamboo rabbit(Wills),on the old Garden Web,talking about one of his friends who used a fertilizer for potted Blueberries,with that in it and they died.
It is supposedly the Chlorides that harm the plants,especially if they are young.
Potassium from Potassium Sulfate is a better choice.
Personally,I use Jack’s Professional 21-7-7 Acid,from AM Leonard in 25# bags.All my plants are in pots or grow bags,except for one.It is water soluble,like Miracle-Gro.Another,which I started with,was J R Peters Jacks Classic 17-6-6 Acid Special Fertilizer,which comes in smaller containers,if there are only a few plants to feed.
If buying from AML,they have free shipping sometimes.
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Thanks for all the replies!! Ideally I want try something that require no mixing beforehand. Also I am looking at osmocote plus and wondering if that would work. It is 8.4% ammoniacal nitrogen and 6.6% nitrate nitrogen. But is the nitrate form of nitrogen ideal??
Most of these products only slightly acidify. That is great if the soil/potting mix is acidic already–but not if the soil has a neutral or nearly neutral pH.
Fertilizing and acidifying in most cases are separate steps.
Osmocote plus is a better choice for it contains other minerals that a healthy plant needs.
I would not be worried about using ammonical nitrogen, or nitrate nitrogen because they help a plant grow in different ways. I have read that ammonia , or urea N. helps grow lush green leaves, and nitrate N. helps grow plant structures.
Ahh great point blueberry. Yes most of my container blueberry plant are in a very acidic medium that only consist of pine bark and peat moss with the majority of watering from rain water. I measure the ph monthly with the bluelab ph probe/pen and they are all tethering on a ph of 3.9-4.5. Really just want to push the growth of these smaller 1-2 year old plant with the less amount of work possible. No mixing of fertilizer and just put in some amount of time release fertilizer n quick watering from our garden hose.
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Then Ammonium Sulfate is probably the thing to use.It’s like a steroid for Blueberry plants.Only watch the dosage.
The nursery pros often use Osmocote for in-pot plants. You don’t need to use particularly acidic fertilizer… better to take care of that with sulfur or aluminum sulfate. It is often suggested that blueberries don’t respond well to nitrate fertilizers so probably best to use something not past ammonium. Hard to believe nitrates can be that much a problem since they from naturally in the soil anyway as the last phase of useable N as it transforms. There is a lot of advice coming from universities suggesting dire results from using nitrate but the nitrate in Osmocote apparently does not hurt blueberries, maybe because ammonium is the dominant one used. I think the main problem with nitrate is that blueberries can’t absorb it.
At any rate any ammonium or urea based source of N should work great… if you want to go organic, I recommend your own diluted urine.
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I use osmocote plus and separately add sulfur for my potted blueberries, as others have mentioned
I’ve found the sulfur amount to be surprisingly forgiving, I go by the tables in the OSU guides and later spot check with a pH meter and it’s always about right, even though I’m not super precise with it. sorta makes sense because 4.5 to 5.5 (or 4.0-5.0) pH is a 10x range, a big target
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You can quite easily kill blueberries giving them diluted urine…
go easy on trying to force blueberries.
Neglect is just as good for them in the long run as fertilizer.
But, moderate amounts of sulphur, and small amounts of fertilizer are a good route to take.
Blueberries, in most cases, survive 6.0 and even 6.5. But don’t generally thrive.
I have one large potted blueberry that I’ve added nothing to in over 10 years…and it produces a small handfull yearly. Located in 50% shade in a 10 gallon pot.
(Yes, I should take better care of it…before I kill it.)
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I concur that ammonium sulfate is perhaps the best for pushing growth in blueberries. That is what I use for most of my medium to larger container sized plants. But it is a bit more work mixing it n pouring it. The main issue I have with blueberries in containers as crazy as it may sound…is too low of a ph. A mixture of fine pine bark and peat moss often by itself gives me a reading of 3.5-4.0 on my blue lab ph prob as well as a few other ph strips n reader. Perhaps by using ammonium sulfate…along with hollytone fertilizer…and in addiction of rain water it’s acidity the potting medium too well haaaaa. Perhaps I should go back to watering with a garden hose……
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You can kill any plant with careless use of quickly available N, but I’ve been using my urine for about 50 years, including for young vegetable plants and have never killed a thing with it- I can’t say the same thing for urea or even dried blood. Blueberries I fertilize right around first growth giving each one of my 30 year old plants about a quart of straight urine- not dilute. I have 8 plants and my freezer still holds about 4 gallons of fruit although I eat some every day- a stuffed gallon bag every 3-4 weeks.
Here’s from a university rec. “One nutrient deficiency we commonly see in the plants is low nitrogen.”
Lots more on blueberry nutrition in the entire link: https://extension.psu.edu/keys-to-establishing-a-successful-blueberry-planting.
So how often have you killed blueberries with excess N?
Mine thrive in soil that the top 10 inches are at about 6.2 but the pH drops to 5.6 below that. I’ve come to the conclusion that the literature is not really correct and plants can thrive in lighter, well drained, high organic content soil at higher pH than usually recommended. I have seen this at several locations over the years.
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Often I kill using excess N? (Or urine?)
About as often as I kill them from neglect.
Far too often or I’d have a larger collection of blueberries than I do.
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I have to agree with Alan. The most difficult plant I have has been my Tea camellia. If you give it any nitrate fertilizer, it will give you the finger. The urea in urine generally breaks down into ammonia fertilizer as it ages. Undilute urine is better for many plants than slow-release Osmocote. It sounds gross, but urine is a superior source of nitrogen for many plants. Just make sure you do not have an excessive sodium consumption if you are fertilizing with your urine. Some plants do not respond well to sodium.
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I can second that. My blueberry patch gets watered by all 3 of my kids when we are outside. All it has seemed to do is make more buckets of blueberries.
Does anyone have an idea how long blueberries can live? Mine were planted by the previous owner in 1980 and were honestly my favorite thing about this property. They seem to be thriving, but I had read somewhere they have limited lifespans.? I have never fertilized them in the 17 years I have lived here besides my kids “watering” them. They get silted 5-10 times a rainy season because they were planted in the floodplain of my creek. I figured someone here may have an answer for how long they may live…
Thanks, and happy growing.
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Where I live, blueberries do too, so as long as you aren’t trying to grow them in heavy soil, they tend to thrive once they establish.