Dahlia fertilizer

Aptos, CA

Sadly Miss Daisy I am digital camera challenged...( today is our 28th wedding anniversary and I bought "us" a digital camera ), the other problem is...SLOW dial-up modem...no DSL in these here parts yet, but soonly...Right now it would take all Autumn to load a picture...Also the brand of humic acid I use is "John and Bobs" www.johnandbobs.com
Don't let the price scare you, one small bag covers 2000 square feet and it is used 2 times a year. We have optimal natural soil where I live, but I still add stuff to it.
With any luck...I'll get some pix upfairly soon.


Albany, OR(Zone 8a)

Ok, just would like to see your dahlias since you seem to really take good care of them.
That camera sounds like a good gift for "both" of you guys, hehe.
Understand about dial-up, etc. Hope you can get DSL or broadband to enjoy all these pictures of the flowers and plants.

Union City, CA(Zone 9b)

New here , but I read the same thing . I use 0-10-10 on my roses from mid Nov . till late Feb . After reading it 4 or 5 years ago ,thats all I put on them , the Canna's , Lillies and rest of bulbs except the onions , garlic and Orchids .0-10-10 should be on sale right now .

Stanford, CA(Zone 9b)

Having the same problem I had last year. This time of year I get weak flower stems and they bend under the weight of the flowers. Any suggestions?

Issaquah, WA(Zone 7a)

Doss, I think it's just the changing sun and dwindling nutrients; happens every Fall here too. I've heard that Potash is the thing for stronger stems. 0- 0- 50. And if you want some sleepless nights: throw on some 20-0-0 nitrogen late season like poor Poochella. Still in denial. It did NOT get to my tubers. It did not get to my tubers. It did not get to my tubers.....

There is a newish garden bed that I need to amend for a few years. Do you think I should add compost now, or wait until Spring? or both? I just want it to aerate and lighten the soil a bit.

Stanford, CA(Zone 9b)

I'm sure that you'll have nice very green plants - are you worried about the tubers rotting from too much nitrogen?

I live in warm land and I don't pull my tubers, but it makes sense to me that if you put the compost in now it has more time to age.

Thanks for the potash help. The season is almost over so i think that I'll wait until next year and juice them with the potash formula toward the end of August. What do you think?

Issaquah, WA(Zone 7a)

Can't keep my p's straight, sorry. Looks like it's POTASH for stronger stems. See this article. Have always read to add fertilizers/amendments before planting so it's in the soil ready to go. But that varies with what you read!

Here it says to add at planting time and again in July.


One place (colorado dahlia society website)
said to add amendments and fertilizers in fall!
This just doesn't make sense to me and I will email them as to why this is on their website.
What a vast array of info is found on the net. I did see mention of better colors to blooms in an English article too. Perhaps those alfalfa pellets of yours come into play there with some secret ingredient.

Stanford, CA(Zone 9b)

Aha! Thanks a million. Here's the answer to too much nitrogen supplied too. It's worth a try. So Phosphorus and Potash are both required. After reading this I'm wondering if in fact the alfalfa provided too much N. My plants were very late blooming this year. They weren't tremendously bushy this year.

"Phosphorus is essential to all plant functions and is a very important fertilizer. It hastens blooming, stiffens stems, increases root development, and balances any excessive nitrogen applied."

It sounds as if adding phosphorus now might not even be a bad idea. Times for fertilizing are strange. I've always heard to feed trees in the fall too. But if you're going to lift the tubers, it doesn't make any sense to feed now does it?

Here's a link to 'Super Phosphate'

Clearly Phosphate and Potash are the balance to N. So this leaves me a little confused. Does adding separate fertilizers of Phosphate and potash make sense or does a very low N fertilizer do the same thing?

Albany, OR(Zone 8a)

Hi Annie,
I would add compost whenever you can. Never be afraid to put in compost at any time.
I would put the compost on now so the worms can be doing their job thru the wintertime and the rain will help with the composting process. The earlier and longer the compost gets working, the better the soil will be. Just like that lasagna layering.

Issaquah, WA(Zone 7a)

Thank you both. I agree Doss, adding something now when I'm feverishly digging them out of the ground will not allow for any absorption; doesn't make sense. But come Spring, I'll be out there phosphating and potashing for all I'm worth! Fie on Nitrogen is my new battle cry.

I am still optimistic that the time release nitrogen didn't get enough time to do damage. Could be wrong of course, but the tubers coming out of the ground seem very sound as in the past. What a few months will bring, I don't know.

Carol, how is your Dad? I've been thinking of you and your recent strife.
I agree, compost is a girl's best friend. If time allows I will dig some in this Fall- there is so much to do! But always, always, in the spring I add whatever is ready and hope to save some for mulch as well. I revere my worms! Feel bad if I hack one in two with an accidental shovel or fork in the wrong place. They are cheap labor in the garden!

Albany, OR(Zone 8a)

Hey, Annie, Dad is doing better. I came home tonight. I thought about you driving down I-5, wishing I knew your address to stop by to see your place. Next time maybe.

Yes, Nitrogen is dahlias enemy, more or less. I try to keep the N level down very low.

Issaquah, WA(Zone 7a)

What an airhead I am! Sniffing too much vermiculite, I guess. I meant to say Phosphorus, not potash again. Geez. You read it correctly Doss, Phosphorus for stem strength.

Issaquah, WA(Zone 7a)

Carol, glad to hear your Dad is improving. What a good daughter you are to help out. You could have stopped by! Jolene from UT made it out to see my messy, messy mess a week ago, but I was in Seattle at the time and didn't get to meet her.

Next August would be good to see blooms Carol, let's work on a plan or a scheme for a dahlia viewing caper.

Issaquah, WA(Zone 7a)

An update on the kiss of death for tubers:

"We were also told by the Dahlia person we got our tubers from that high N was the eventual kiss of death for the tubers. "

I've been consternating over this high nitrogen thing and asked a grower/analytical chemist whose opinion I highly respect. He says there isn't one smidgeon of scientific evidence that nitrogen has any relationship to tubers rotting. He has asked many times over about this supposed pheonomenon in dahlia circles and always gets the same reply: "heard it from an expert..." That theory is just passed on from "expert" to "expert" but no one can say why, nor have studies been done. Google it, there's nothing out there but hearsay.

Now it could be true that it's a correct informal observation seen and passed on by dahlia growers, but I remain firmly planted in total denial! YAY!
So far I've seen the usual array of tubers come out of my ground and am treating them as always for fungus, drying cuts well before wrapping, and will store in a controlled temperature.

My tuber denial bubble will only burst when I go out to find little saran wrap packets of mush next Spring. I'm crossing my fingers.... that the high nitrogen lie will die an eventual death and will update here if I spot trouble with storage.

Stanford, CA(Zone 9b)

Gee, Poochella. Aren't you clever? You will be the world's expert on whether or not N will be the 'Kiss of Death' for rhizomes and tubers. I can't wait to hear the results.

Good work. :-)

Issaquah, WA(Zone 7a)

Don't get clever and desperate confused Doss! LOL I was just trying to use all resources available ( to support my desired conclusion, of course) Someone would have to be willing to sacrifice tubers in a very controlled nitrogen bath study, to use Candy's words LOL, to make any reproducible conclusions. That won't be me on any large scale anyway.

Stanford, CA(Zone 9b)

I think that your 'experiment' works just fine. No one's going to bath tubers in nitrogen - although maybe Candy might like to??? LOL

Union City, CA(Zone 9b)

I just feed mine yesterday .
0-10-10 .
I have to buy more , I didn't realize the wife filled bottles and MTed bag .
I keep my snail food , different fert. and poisens in a little tote I made . Just shake it out .
I don't like working on plants and having to get up for stuff

Thumbnail by tonyjr
Stanford, CA(Zone 9b)

Very Clever Tony!

Waxhaw (Charlotte), NC(Zone 7b)

I use either 10-20-20 (actually a lawn "winterizer" fertilizer I found in a large 45 lbs bag) or 6-12-12. Latter is available from home depot in a square cardboard box (3 lbs).

As long as the ratios are there (5-10-10, 6-12-12, 10-20-20..) you can just sprinkle a bit around the dahlias.

Eastlake, OH(Zone 5a)

I use liquid kelp while growing them from seed, and during the summer. We get loads of blossoms, and the plants are healthy. We fertilize them with bloom buster. The kelp is used in between fertilization. Ideal stuff for all plants.

Appleton, WI(Zone 5a)

I picked up some fertilizer for bulbs 4-10-6 that I will be trying this year.

Issaquah, WA(Zone 7a)

I can't find the post where someone inquired about rabbit poop: but here is one breakdown of it. Looks to be quite high in nitrogen but remember this is only one website's opinion. Elsewhere it's referred to as "bunny gold" for the garden!

I myself ended up with 10-20-20 this year and to my dismay NO directions other than "this bag will cover 10,000 square feet." Yikes. I'm flying on instinct here and giving a handful to each planting hole, hoping for the best.

Fox River Valley Are, WI(Zone 5a)

Well I have learned from first hand experience that high nitrogen creates lanky stems in peonies and yellow-brittle stems in day lilies.
I just bought 0-45-0 and 0-0-60 for some experiments on my dinner plate dahlias and lilies among other plants like my mamouth sunflowers.


West Caldwell, NJ(Zone 6b)

I had initially fertilized the soil with some organic 0-10-10 stuff that was actually for Bonzai trees. I also have ordered some Alaskan Morbloom, but now I received a catalog for Spray and Grow, from which I ordered the Spray and Grow, Bill's Perfect Fertilizer, and Coco Wet, which you combine and feed the plants with through the leaves (the Coco Wet keeps it on). Anyone used this before? Will let you know how it goes.

New York & Terrell, TX(Zone 8b)

Issaquah, WA
Zone 7a

Nov 14, 2005
1:53 PM

My tuber denial bubble will only burst when I go out to find little saran wrap packets of mush next Spring. I'm crossing my fingers.... that the high nitrogen lie will die an eventual death and will update here if I spot trouble with storage.

How'd they do Poochie?

~* Robin

Issaquah, WA(Zone 7a)

Well, about 98% of them did very well until I foolishly brought them into room temperatures without unwrapping. Mold, mildew, rot ensued into total chaos while I unwrapped as fast as I could in the warm climate.

Had I kept them in cooler temps, I'd guess I would have had very close to 90+% storage success. I'll do the same thing next year, only will not bring inside so early without unwrapping first. I am sold on Saran type wrap.

Further, I am convinced higher nitrogen during the growing season had no effect on tubers/storage either. All plants were treated equally.

Portland, OR

sorry to be such a dummy, but I am new to this. what does "sticky" mean? Is there a place I can go (web site) to learn all this lingo? thanks!

Fox River Valley Are, WI(Zone 5a)

Sticky means it is stuck to the top of the forum...

Beachwood, OH

Way late to this thread! I planted with Espoma Bulbtone on mine last year under the assumption that they would be closest to a bulb - hee hee. I also used tomato fertilizer later in the season under the assumption that its formulated for fruit (flower) production. Worked out fine but was not scientific by any means.

Provincetown, MA

How do you "Stick" something to the top of the Forum? "Sticky" (I'm also new to all this)? I am way, way, late to this forum and read it with gusto, because I was going to pose the same original question. Here's what I am experiencing if anyone out there is reading this late post: I have grown lovely dahlias in complete ignorance for a few years using all sorts of fertilizer (composted cow manure, bulb fertilizer) with great results. This year I ordered from Lynch Creek Farms (seems like a nice company...the bulbs looked great) and the plants I'm getting now look smaller than the el-cheapo bargain things I bought at sleazy outlets in the past. I did the research that said not to over-fertilize with nitrogen rich stuff, and merely stuck them horizontally in my nice fall-compost rich bed, 4" deep, etc., with a little triple phosphate. The shoots are coming up, but I don't think they look as good as the improperly fertilized overly-deeply-improperly planted el-cheapos in the past. Could it be wrong PH? I guess I should wait to see what the flowers do in a few weeks, but so far I am puzzled by all I have read here. I am feeling as if all the "wrong" stuff I did with crappy bulbs performed better at this point. And another question, while I'm at it; One of my friends here on Cape Cod, zone 6, swears that if the plants are deeply mulched in fall I won't have to dig them up. I am skeptical, but open to advice from you all. Cape Cod, by the way, has inconsistant winters, tho it is now zone 6. Any thoughts?

Olympia, WA(Zone 8b)

That place, lynch creek, is just up the road from me, lemme know how they do for you. I bought one in a pot from them about 6 weeks ago, and it already has a bud on it. I am SO excited!!

Best Regards;

Issaquah, WA(Zone 7a)

Welcome Blackbunny. You are in a beautiful part of the country, but I've seen the beastly winter weather reports for the Cape and wouldn't want to chance leaving my tubers in the ground. Maybe try it on a couple, mulch very heavily if you do.

I don't know an answer on the "sticky" status. Maybe other DGers will. Perhaps you need to ask Administration to create a 'sticky' message so it always stays on the top of a forum.

I've tried, bulb fertilizer 10-10-10 with so so results. I've used 19-14-12 Osmocote which is really easy: one feed per season and you're done. I've used MorBloom when buds are setting and didn't really notice a difference. This year I went with 0-20-20 lawn fertilizer until I saw buds forming on very squat plants and said to heck with this I want nitrogen! So I added veggie Osmocote at something like 14-12-? and already the plants look better to me.

Your compost sounds wonderful and well-draining, a most important thing to a tuber. It probably wouldn't be a bad idea to test your pH aiming for something around 6.5, I think. We are naturally acidic out here, so I don't bother. I think if you have pretty healthy soil and work to keep it that way, you'll have a shot at healthy plants.

Have you searched online for a Massachussetts Dahlia Society you could email about the overwintering question?

Beachwood, OH

I forgot to say that I used Messenger on my plants this year. Very odd results this year but I'm not sure I can conclude Messenger is the cause. My dahlias are no more than 20" high and all but the dinner plates have buds on them. Bishop of Landaff and York, the dinner plate dahlia Otto's Thrill, various other cactus and pompon types - all of which should be 3-4' tall. We had a very dry May - hot with no rain for 3 weeks, followed by a very wet June and July with almost daily heavy cloudy and rainy conditions. I've fertilized once with Mighty Plant which is 18-18-18, once with Fish Emulsion and sprayed Messenger on once. I don't have good plant growth which I attribute to either weak tubers or poor growing conditions this year for dahlias, but the buds would lead me to believe that Messenger stimulated them. My schedule says to spray again with Messenger next week and I guess I'll do it. If we would only get some decent days of sunshine.... I love my dahlias.

I have a full perennial garden that pretty much blooms itself out by August except for some plantings of fall bloomers. I grow all my dahlias in containers on the deck in new Pro-Mix and they take over with killer color until frost. Last year was my first yr with Dahlias and I fell in love with them so I'm anxious to have a reprise. Unless it can be blamed on the lack of sustained sunshine I don't understand why my plants are small.

Beachwood, OH

I looked at all kinds of low N fertilizers and finally settled on Espoma's Tomato-tone which is low N, high K. I really think I'm going to head out in the country to the Tractor Supply and buy some Triple Phosphate and bone meal. I'll run out of the Espoma long before the season is over.

Baltimore, MD(Zone 7a)

I am jumping in on this thread to ask a question....Are Dahlias considered Annuals...perennials...bulbs? I am curious because of a flowershow where I had placed them under annuals and it was wrong...

Issaquah, WA(Zone 7a)

Someone at that flower show should have shown you the right place for them. Maybe they didn't know either!

I would put them in the bulbs section, although the correct term for their rooty growth is tuber.

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