Anyone try the new foam fertilizer yet?

[Gymnotions]

I've always used liquid Miracle Gro cactus and succulent fertilizer. I just went out to buy another bottle and discovered, after stopping at several stores, that Miracle Gro doesn't make that any more, and now they are pushing a spray foam that you spray on the soil, then water.

I'm hesitant to use it. Has anyone tried it yet?

[cortez753]

You really should use a better fertilizer with better micro nutrients such as dyna gro 7-7-7. I wouldn't use it.

[DaveW]

I see their site says for the foam:-

"Fertilizer Analysis 1 - 1 - 1"

So since it has been pre diluted it's exactly the same ratio as 7 - 7 - 7 after dilution to one seventh strength? Both are really just conventional plant fertilisers though and not specially compounded for cacti, but probably OK if you don't over fertilise and over use them.

Cactus fertilisers are usually lower in nitrogen. I see Miracle Gro Cactus fertiliser was 2-7-7, however I cannot find any information if it contains trace elements as some other Miracle Gro products do.

http://www.miraclegro.com/smg/goprod/mi ... od10600026" onclick="window.open(this.href);return false;

Whether you need a fertiliser with trace elements depends what you grow your plants in and how often you re-pot. If you use soil based mixtures they should contain most of the trace elements needed anyway. However if you follow the modern trend for purely mineral mixes these may be poor, or even deficient in some trace elements and need regular fertilisation, rather akin to hydroponics where all the plants needs have to be artificially supplied and the medium they are growing in is just a neutral substrate there simply to provide support.

I am not sure cacti need such high nitrogen levels as 1 - 1 - 1- or 7 - 7 - 7 though, which are exactly the same proportions except one is more dilute than the other. However it probably depends whether the soil in the pot counteracts this by providing additional phosphorus, but long term unless you regularly re-pot that could gradually be depleted and the higher nitrogen levels become toxic.

The Cornel University recommends:-

"During the active growing season, a monthly feeding of 15-30-15 is advisable, a high nitrogen fertilizer would promote soft, flabby growth."

http://ccenassau.org/resources/cacti-an ... succulents" onclick="window.open(this.href);return false;

"Nitrogen helps plants make the proteins they need to produce new tissues. In nature, nitrogen is often in short supply so plants have ev0lved to take up as much nitrogen as possible, even if it means not taking up other necessary elements. If too much nitrogen is available, the plant may grow abundant foliage but not produce fruit or flowers. Growth may actually be stunted because the plant isn't absorbing enough of the other elements it needs.

Phosphorous stimulates root growth, helps the plant set buds and flowers, improves vitality and increases seed size. It does this by helping transfer energy from one part of the plant to another. To absorb phosphorous, most plants require a soil pH of 6.5 to 6.8. Organic matter and the activity of soil organisms also increase the availability of phosphorus.

Potassium improves overall vigour of the plant. It helps the plants make carbohydrates and provides disease resistance. It also helps regulate metabolic activities"

Really it all comes down to what works for you and how you prefer your cacti to look, big and green with less dense spination, or where the spination may completely obscure the plant body as with plants in habitat? If you are regularly feeding fertilisers with equally balanced N - P - K ratios, an occasional feeding with a tomato fertiliser may help to increase the phosphorus levels and counteract the high nitrogen content of your regular fertiliser.

[cortez753]

Analysis is on back label.

http://www.miraclegro.com/smg/products/ ... oodcfl.pdf" onclick="window.open(this.href);return false;

[DaveW]

The Cactus feed does contain some trace elements then, but does the foam stuff?

[iann]

Foam label:
http://www.miraclegro.com/smg/products/ ... t_Food.pdf" onclick="window.open(this.href);return false;

Another brilliant idea for parting fools from their money.

[A. Dean Stock]

The "foam" fertilizer is a great rip-off by our friends at Miraclegro!! A lot of money for not much of anything. You probably don't have to worry about too much nitrogen because 1/2 of what little is there is in the form of Urea and unless you are keeping your cacti way wetter than I do, most of that urea is going to be flushed out on the floor of the greenhouse or down the sink.
Dean

[iann]

The "foam" fertilizer is a great rip-off by our friends at Miraclegro!! A lot of money for not much of anything. You probably don't have to worry about too much nitrogen because 1/2 of what little is there is in the form of Urea and unless you are keeping your cacti way wetter than I do, most of that urea is going to be flushed out on the floor of the greenhouse or down the sink.
Dean

Where do these ideas come from? Who leaches through their pots immediately after they fertilise? And if they did what makes you think urea would get washed out faster than nitrate or even ammonium? Urea is *less* prone to leaching than nitrate - the nitrate it produces could leach, but it is produced gradually and should be taken up by the roots unless you went nuts with the fertiliser. Any soluble fertiliser can be leached if you follow up with an excess of fresh water, especially in low-organic low-clay soils. Ammonium leaching is usually ignored, but it occurs readily in low-CEC soils such as a cactus soil. Best not to rely on any nitrogen being bound in a cactus soil from one watering to the next (hence the little and often rule).

Urea volatilisation is the usual main source of losses, but is uncommon with soluble urea because it is necessarily incorporated through the pot. You might get some losses in extreme cases with high temperatures and alkaline soils, but it is pretty much a self-limiting process once you get the urea within the body of the soil. I suppose the urea in the foam might volatilise, except the instructions say to water in immediately so it shouldn't be an issue.

Or perhaps you're under the impression the urea won't get nitrified in soil that is only slightly moist? Also untrue. Soil moisture levels don't need to be high for nitrification, but it can be inhibited by excessive temperatures, waterlogging (probably not an issue), and acidic soils. Urea can be taken up directly by roots, but nitrification usually converts urea faster than a plant will take it up.

[A. Dean Stock]

Iann, my 50 years of growing orchids and cacti and a lot of experience measuring what comes out of the pot caused me to make that comment. I believe that you are wrong about so called nitrification taking place easily with urea under general cactus growing conditions. Urea must be processed by bacteria to become available to the plant to any large extent and that requires more moisture than most cactus growing conditions provide. I do realize that it is often almost too moist in your part of the world so that might make some difference in experience. The entire orchid community that is more dependent on good fertilization than cactus growers and discovered the problems long ago and most do not use Urea based fertilizers.
Dean