help with fertilizers for container gardening

13 years ago

I made a post in the soils subsection forum about a soil test. People have told me continously to get a soil test before I add nutrients to my soil mixture so that I know what's in it. I told them I do know what's in it because I make my own soil mixture for container gardening. They said since container gardening soil is soilless, that a soil test is unneccessary.

I then told them I was looking for a high potassium and high phosporus fertilizer because this is what fruiting plants (plants that are harvested for their fruit.....any type of squash, any type of melon, any kind of bean, peas,

bell peppers, eggplants, tomatoes, etc.) as well as

veggies grown for the root portion (beets, carrots, turnips, kohlrabi, etc.) require this type of fertilizer.

They suggested that I post my inquiries about looking for a high potassium and high phosporus fertilizer that is suitable for container gardening here on this forum, since

it's the method I use for gardening.

Can anybody recommend any brand name fertilizers that would be available anywhere (such as local hardware stores, local garden supply shops, Walmart, etc.)

Also I normally just stir in a dry fertilizer into my soil recipe, as the recipe I use for container gardneing, that is what is specified to do with the instructions for making it. Would I be able to just stir in a liquid fertilizer when making my soil mixture, or would this create problems? I don't know, as I've never done this before.

Also if you add fertilizer when you make up your batch of soil for container gardening, will it be necessary to

apply fertlizer later when the plants start to bare fruit (this is specifically applied to squash, eggplants, tomatoes,melons, and bell peppers, as I realize they're heavier feeders than root vegetables)

Featured Answer

gardengal48 (PNW Z8/9)

13 years ago

last modified: 9 years ago

I tend to approach fertilizing containers rather simply :-) Al can provide all the science behind it but my experience in the nursery industry that I have transfered to my personal growing situations has worked out great for me - healthy plants, lots of flowers, good crops.

I use an extended release fertilizer when I make up my mix and pot up the plants. Osmocote is a popular brand and is carried darn near everywhere - Ace Hardware, Home Depot, Lowe's, pretty much any garden center. It comes in a variety of formulations but I use the Osmocote Plus Multi-Purpose (actually a related similar brand sold for commercial applications that I can get free from my nursery).

For my long term container plantings - trees and shrubs or mixed perennial containers.....anything that lasts longer than a single growing season - I reapply the Osmocote each spring as new growth begins or when I repot. It lasts about 6 months and provides virtually everything the plants need.

For single season plantings, I supplement the Osmocote with a liquid fertilizer frequently during the growing season. I use a liquid organic product made locally but any kind of water soluble or liquid fertilizer will work as long as it provides the full range of nutrients. The Dyna-Gro suggested above, MiracleGro, Peters or various local brands will all work. Just read the labels to make sure they have necessary trace elements included. These are often found in formulations that encourage fruit and flower development -- lower in N and higher in P or K.

Fertilizing throughout the growing season IS necessary for single season plants like annuals and veggies. Because they complete their lifecycle in a single season and produce a lot of flowers or fruit, they pull out a lot of nutrients. Plus the need for frequent, often daily (or twice daily) watering leaches nutrients out of the planting mix as the water drains and these need to be replaced.

Long term plantings - trees, shrubs, etc. - tend not to have as strong a nutrient demand, so the slow release fert works well. It is what most nursery growers of container plants use. The nutrients still leach out but because they are released to the plants over an extended period, it is not quite so critical as it is with single season plantings. I still hit 'em with a dose of the liquid fert every now and again just to be safe :-)

Not everyone may agree with me, but I think there is a tendency to overthink fertilizing. Trying to get too specific regarding the particular nutrient requirements of various plants can drive you nuts! Just make sure the product you use has the necessary trace elements included. FWIW, the liquid organic product I use is considered an all-purpose, or all three numbers the same -- good for ANY plants. It does contain a full range of trace elements as well. All the container veggies I grow respond well to this product, so I don't bother with one intended specifically for fruit and flower production.

But what works well for me may not be the same for everyone.

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Comments (6)

prestons_garden
13 years ago
last modified: 9 years ago
I would try to keep it as simple as possible. One can get easily carried away and spend a small fortune in fertilizer additives when it is really not necessary.

Tomato Tone makes a decent organic fertilizer and Dyna-gro makes an excellent complete synthetic fertilizer.

Just follow the directions on what ever fertilizer you purchase and you should do just fine.

Yes, you will have to add more fertilizer as the season goes on, again follow the directions.

If I were you, I would go with Dyna-gro, this stuff works great and you get very fast results. Most people on this forum like the Foliage-Pro 9-3-6. You can also get Dyna-gro Bloom 3-12-6, if you desire, so you can switch when your plants start to bloom.

Others will contribute with there experience in fertilizers which a few I'm sure you will want to consider.

Good Luck,

Ron
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jodik_gw
13 years ago
last modified: 9 years ago
I would agree... I think people tend to over think fertilizing, too... I think that as long as the fertilizer you're using contains the necessary micro-nutrients, or you're adding them to a fertilizer that doesn't, you're pretty much covered.

I use Miracle Gro liquid all-purpose plant food, with the addition of micro-nutrients. I'd prefer to use Foliage Pro, but I'm not wasting what I already have.

The industry doesn't make it any easier, either... the shelves at garden centers contain all manner of fertilizers in different proportions, and plenty of specialized types, as well. I don't think many of them are necessary, and with all the choices, it's confusing. It leads people to think there's a lot more to it than there really is.

The bottom line is... the industry is trying to create profit, not great gardeners. Feeding our plants effectively shouldn't be such a difficult task.

I use nothing more than an all-purpose liquid on my potted plants, adding the micro-nutrients that Miracle Gro doesn't have... and on the gardens, I use composted manure and the leftover water from our duck pool. That's it. I'd never go organic with my container plants, simply because of the vast differences between growing in pots and growing in the ground... but I agree that feeding plants is not as complicated as many people think it is... or the industry would have us believe.
mgbeheler
12 years ago
last modified: 9 years ago
I have Miracle-Gro 12-4-8 All purpose Plant Food, but plan to switch to the Foliage Pro 9-3-6 when it runs out. In the mean-time, what "micro-nutrients" are needed, and how do I get them? I need to feed an 18" tall brown-turkey fig that I bought last summer.
Afterthought: Do you know if fertilizer can go bad? Lose nitrogen, or anything like that? I think this jug is about 3 years old. (My houseplant plantation is very small.)
tapla (mid-Michigan, USDA z5b-6a)
12 years ago
last modified: 9 years ago
Synthetic forms of fertilizers, like MG and others, have indefinite shelf lives. If you're using FPO 9-3-6 ..... it's in there. IOW, it's a fertilizer that supplies all the elements required for normal growth that plants normally take from the soil.

From a practical perspective, I've been using 3:1:2 ratio fertilizers for a good number of years, with every plant I've used them on (hundreds and hundreds) responding to them with nearly uncontained abandon. ;-) (they all responded well - I might have been just slightly carried away there).
Al
TheMasterGardener1
12 years ago
last modified: 9 years ago
I am using a dry fertilizer with no urea N. It is 5-15-14 and has 5% Ca, 3.5% Mg, 4% sulfur and .1% iron. It is called maxibloom made by General Hydroponics. The other micro are easy to supply using miracle gro. When it comes to tomatoes and peppers you want a blooming formula with levels of Ca.

help with fertilizers for container gardening

gardengal48 (PNW Z8/9)

Comments (6)

prestons_garden

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jodik_gw

mgbeheler

tapla (mid-Michigan, USDA z5b-6a)

TheMasterGardener1

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