I am getting into container gardens and wondered how often and what everyone is using to get these gorgeous container photos. I live in an extremely hot zone and need to frequently water(though have experimented with some coir from BocaBob that seems to really be helping in that area) Now I think they need more food. Foliar feed? Seaweed and fish emulsion? Miracle grow? what are your secrets??????
fertilizer and containers
I use Miracle Grow Bloom Buster when I think about it. At least once a month. I really like the new applicator that uses the liquid fertilizer.
If you're results oriented and want 'easy', there is no question in my mind that soluble fertilizers are the answer for container plants. You can MAKE organic programs work, but I can almost assure you your results will be more erratic than if you chose an appropriate formulation of a soluble fertilizer. BTW - fish emulsion is not soluble. It forms a suspension of organic molecules that soon fall out of suspension. These molecules need to be broken down into elemental form before they can be assimilated by plants.
The best all-around choice for your fertilizer program (containers) is a 3:1:2 RATIO fertilizer like MG 24-8-16 or 12-4-8. Foliage-Pro 9-3-6 is also a 3:1:2 ratio fertilizer that has all the secondary macro-nutrients + all the necessary minor elements, and all in a favorable ratio. It also derives most of its N from nitrate sources, so there is less worry about ammonium toxicity issues (common, but rarely diagnosed properly) when temps are above 80 or below 55*. It's a great choice.
I'm sorry, Irwells, but there is no way to justify recommending the use any kind of bloom-boosting fertilizer formulation in container culture unless you are using it for very specific manipulation of a decreased N supply, but even then it would have to be supplemented with K to be effective. Plants use an average of 6 times more N than P, so to supply more P than N is a waste. The plant can never use all that P before it needs more N, so ALL bloom-booster formulations (with P as the highest % of the fertilizer - middle NPK # highest) unnecessarily raise the electrical conductivity and level of total dissolved solids in the soil. This makes it more difficult for plants to absorb both water and the nutrients dissolved in water. The high P content also raises pH unnecessarily AND can cause antagonistic deficiencies of other elements, particularly Fe and Mn.
Al
This message was edited Jul 30, 2009 2:03 PM
This message was edited Jul 30, 2009 3:31 PM
Okay, well, I'm pretty happy with the way mine look, and am out of the Bloom Buster in any case, and will probably use up the 2 regular Miracle Gro I have on hand.
I'll look for the ratio you mentioned, but was interested also in how often to apply it to containers, especially when it is so hot. Every watering seems excessive, but wasn't sure if a diluted mix every week was better than the recommended strength every two weeks, or even once a month..
That's kind of difficult to answer. Most soluble fertilizers derive their N from urea, so you should avoid fertilizer applications when soil temps are below 55* or above 80* because of the ammonium toxicity issue mentioned upthread. Soluble fertilizers deriviong their N from nitrate sources aren't as much a consideration.
There is a fair amount of judgment in properly applying fertilizers, and 'properly' has little to do with a schedule. How fast your soil is and your watering habits are the largest determining factor. Then, you need to consider mean temperatures and how robustly the plant in increasing in mass. You might be right on target, fertilizing a plant in a fast soil at full recommended strength weekly, but a plant in a water retentive soil may only tolerate the same dose bi-weekly or even monthly.
You're better off to fertilize more frequently at lower doses than infrequently at recommended maximum doses. It's also better to either apply a stronger solution ( within recommendations) when the planting is growing robustly, or decrease the interval between fertilizer applications.
There are so many variables that I'm afraid there is no one-size-fits-all answer.
Al
Good info for trying to decide. I think when things are stressed here it will help to be gentle(kind of like Mom's chicken soup when you're sick). I tend to use fish emulsion and seaweed when my in-ground plants are first planted, so I'll go that route during the summer, though at a diluted rate. We have such a long growing season I'll reserve the soluble fertilzer for that spring jump start and then start again when it cools off in September.The info about the micronutrients was interesting. I heard the soil around here can have iron tied up because of the high Phosphorous content (I think that's it anyway).Someone on the radio said we don't need to ever have the middle number on lawn fertilizers be anything but 0 because of that.And I know that's how several fertilizers sold around here are labelled...
Remember that your FE will be very ineffective at temperatures below 55* and higher than 80*. Carry-over can be an issue as well. E.g., if you fertilize with FE when it's cool & don't get results, you may tend to fertilize again, or again and again, thinking "it's not working", but organic fertilizers accumulate more readily in soils and can become available in concentration when soil temperatures warm (or cool). This can lead to unexpected burning or ammonium toxicity, which is usually then attributed to some other, unrelated cause.
Al
I didn't know that about fish emulsion. Does the same hold true for seaweed?
I use a good slow release 14-14-14 Smartcote for Hanging Baskets in all my containers at planting time. Since they get watered way more than the flower beds, especially later in the season, which is now for us and when they get a bit root bound, I use Miracle Grow Ultra Bloom 10-52-10. I have done this for a few years and have found that it makes a huge difference. I notice a lot of neighbor's baskets look terrible by Mid August and mine keep going until a hard frost.
I'm sorry, Joanna, but your plants aren't looking good BECAUSE of the bloom booster fertilizer, they're looking good IN SPITE of them. Even the 14-14-14, like all 1:1:1 ratio fertilizers (20-20-20 is another common one) supplies WAY more P than your plants could ever hope to use. In fact, your 10-52-10 supplies 32 times more P than your plants can use. I don't want to offend you, but I am on solid ground when I say that folks who use these high-P formulations are unwittingly doing their plantings a considerable disservice.
Let’s first look at the role of fertilizers in general. There are 6 factors that affect plant growth and yield; they are: air, water, light, temperature, soil or media, and nutrients. Liebig's Law of Limiting Factors states the most deficient factor limits plant growth and increasing the supply of non-limiting factors will not increase plant growth. Only by increasing most deficient factor will the plant growth increase. There is also an optimum combination of the factors and increasing them, individually or in various combinations, can lead to toxicity for the plant.
From the above, we can say that when any nutritional element is deficient in the soil, plant growth slows. We have a term for this occurrence: environmental dormancy. When the deficient element is restored to adequacy levels the environmental constraint caused by the deficient element is eliminated and plant growth can resumes at a normal rate, as long as there are not additional limiting factors. Continuing to increase the element beyond the adequacy range offers no benefits and can deleteriously affect the plant - often in several ways, depending on the element.
Somewhere along the way, we curiously began to look at fertilizers as miraculous assemblages of growth drugs, and started interpreting the restorative (of normal growth) effect of fertilizer as stimulation beyond what a normal growth rate would be if all nutrients were adequately present in soils. It’s no small wonder that we come away with the idea that there are ’miracle concoctions’ out there and often end up placing more hope than is reasonable in them. In couplet with the hope for the ‘miracle tonic’ is ‘more must be better’. I’ll use the latter idea as the lead-in for my thoughts on high-phosphorous fertilizer blends.
Among container growers you often find common belief that high-phosphorus (P) content fertilizers are a requirement for promotion of root growth and/or flowering. Fertilizer blends like 15-30-15, and even 10-52-10 are sold under names that imply that you actually NEED these formulas for plants to bloom well and to produce strong roots. Lets examine that idea in a little more depth.
While anecdotal evidence abounds, there is very little scientific evidence to show any need for such products. I’ve mentioned in other posts that high-P fertilizers are a historical carry-over from when it was most common for plants to be started in outdoor soil beds, the soil in which was usually still quite cold at sowing time. Both the solubility of P and plants’ ability to take it up are reduced in cold soils, so it was reasoned that fertilizing with high levels of P insured that at least some would be available during periods of growth in chilled soils.
We know that tissue analysis of leaves, roots, flowers - any of the live tissues of healthy plants will reveal that P is present in tissues at an average of 1/6 that of nitrogen (N) and about 1/4 that of potassium (K). Many plants even contain as much calcium as P. If we know that we cannot expect P to be found in higher concentrations in the roots and blooms than we find in foliage, how can we justify the belief that massive doses of P are important to their formation?
It is well known among experienced growers that withholding N when all other nutrients are available at adequate levels induces bloom production, even on smaller and younger plants. Though plants USE nutrients at approximately a 3:.5:2 ratio (note the decimal point in the .5, and that N is used at 6 times the level of P, and K is used at 4 times the level of P), most greenhouse operations purposely fertilize with something very near a 2:1:2 ratio to limit vegetative growth so they can sell a compact plant sporting pretty blooms to tempt you.
Simply limiting N limits vegetative growth, but it does nothing to limit photosynthesis. The plant keeps making food, but it cannot use it to grow leaves and extend stems because of the lack of N. To where should we imagine the energy goes? It goes into producing blooms and fruit.
What harm might there be in a little extra P in our soils? First consider that the popular 10-52-10 has almost 32 times more P than a huge percentage of plants could ever use. Even 1:1:1 fertilizer formulas like the popular 20-20-20 are already high P formulas because they have 6.25 times more P (in relation to N) than plants require to grow robustly and normally.
Evidence of phosphate over-fertilizing usually always includes some degree of leaf chlorosis. P competes with iron (Fe) and manganese (Mn) ions for attachment sites and causes antagonistic deficiencies of these micro-nutrients. Unfortunately, the deficiency of these elements causes interveinal chlorosis (yellowing), and the first thing we normally consider as a fix for yellow leaves is more fertilizer, so we give the plants a good dose of our favorite bloom-bomb which causes, no surprise - worsening of the condition.
I’ll close with an anecdote of how I used to fertilize plants with showy blooms before I had a better understanding of the overall picture. I would fertilize with a "bloom-boosting" fertilizer as long as foliage was bright green. As foliage inevitably yellowed, I would then switch to a high N formula until the color returned and start the cycle over again. I THOUGHT that the P was helping produce blooms and the yellowing was caused by a lack of N, which I quickly jumped to correct at the first evidence of yellow. I now understand that the high levels of P were what were causing the yellowing and it wasn’t my returning to a high N formula that greened the plant up again, it was the reduction in the level of P in the soil when I stopped using the high-P formulation.
There is simply no need for any fertilizer with a middle number that is higher than either the first or last (N or K) numbers for container culture unless you're VERY knowledgeable about fertilizers and are using them for a VERY specific purpose, which would automatically have to include a severe reduction in N AND K because they are being derived from alternate sources and there was no other source of P in the soil or finding its way into the soil from other fertilizer sources. There is NO plant that any of us are likely to grow that EVER uses more P than either N or K, so why, oh why would we want to supply so much P? It's because, through ignorance (classic sense of the word - not derogatory), most have been duped.
Al
This message was edited Aug 1, 2009 8:54 AM
Wow, that is a mouth full. I will have to read your posts a few more time to completely understand what you are saying. Despite your comments that the high middle # as being a waste, I have to disagree. For years my baskets looked terrible come August and since I started doing the 10-32-10 in August & September the containers look awesome until frost.
I have a few gardening pals that fertilize with a diluted dose every watering of a balanced 20-20-20, and their containers look fabulous as well. I have too many container to do that, so the slow release seems to be a good alternative. Our growing season is so short and I have been trying different things to keep the max bloom for the longest period.
Most of us are poor observers and get cause/effect relationships wrong all the time. You just know that your plants are looking better since you started using a bloom-booster fertilizer, but it's illogical to assume that is the only possible cause. If your plants are looking better, it is for some other reason than the high-P fertilizer. While, by anecdote, you relate that your plants look better because you are using a fertilizer with a very high P content, by science I can tell you that cannot possibly be so.
You're on a road trip and are behind schedule. You look at your gas gauge & see there is only 1/4 tank left. By your reasoning, filling the tank will make you go faster. We KNOW by science, it won't; and adding huge amounts of P will not make your plants bloom better - it is actually quite bad for your plantings. Or - you get a chain letter that threatens you with dire consequences if you break the chain. you laugh and throw it in the garbage. On your way to work the next day (God forbid) you slip and break a leg. When you get back from the hospital you send out 200 copies of the chain letter and add an extra note telling people they had BETTER forward the chain letter because you have PROOF that bad things will happen if you don't.
Things are not always what they seem. Practically on a daily basis in my forum travels I run into folks who attribute how their plants react to causes that cannot even be remotely related to the effects. High-P fertilizers/blooming are often one of those very misunderstood cause/effect relationships. Plants need no more P during their reproductive phases than they do in any of the other life phases, and they only need about 1/6 the P as N. 24-8-16, 12-4-8, 9-3-6, or any of the other 3:1:2 ratio fertilizers do that best.
A true anecdote: Last Sep 23, I had the Gladwin County, MI Master Gardeners tour my gardens. Almost without exception, they couldn't get over how gorgeous the containers still looked. Is it logical for me to observe that because my containers looked so good in late Sep, and yours only looked good in Aug, that using 24-8-16 fertilizer is better? No, it's not. What IS logical though, is to make the observations that A) You certainly do not need a high P fertilizer to have good looking containers late into the year B) That, since science supports the fact that they are far more likely to be harmful than helpful, it's a bad idea to use them.
As usual, I'm not trying to get you to change anything ..... I just don't want others to follow suit based on erroneous observation. . Because you still disagree, the conversation should be considered as leaning more toward enlightening those listening in, than as an attempt to get you to change anything. I'll have to point out though, that just thinking you are seeing a benefit from the high-P fertilizer and relying on that singular thought as the basis for disagreement is a long way from presenting a convincing case to the others. ;o)
Al
A September container:
Teacup, your problem with iron binding in the soil is more likely due to the alkalinity of your soil; iron shortages are chronic in such soils, even though the soil itself may be rich in iron. That shouldn't be a problem in container media, unless you're using your own soil as part of the mix, and then it'll be a matter of degree.
Al's point about the composition of the media is really about its ability to retain nutrients long enough for the plant to use it without undue accumulation of salts, which result in the dire consequences he describes above. It all depends upon your willingness to commit to a feeding/watering schedule that provides nutrient when it's needed, but not subscribing to the notion that more is better. Remember, a plant can only use so much nutrient over a certain period of time; the efficiency of nutrient delivery is the biggest determinant of success or failure, otherwise you're pouring money right through the bottom of your container, or working counter to your plants' best interest through excessive salt accumulation.