My soil test dropped from P 515 down to 363 and k 958 down to 568 in one years time by not add organic matter and only growing a cover crop. Test was done with mehlich-3 standards. I also had high Zn. Last year was so terrible it is hard to judge anything from it. I think a lot of my high reading was caused by tilling in uncomposted oak leaves.

Hi Sammie,

Did they give recommendations on the soil test? I take my soil to the OSU extension agency and they will tell me what to use and how much. If you didn't get any recommendations you could use ammonium sulfate (you can get it at Home Depot)the sulfur will lower the ph and it will only deliver nitrogen fertilizer. Nitrogen is almost always low because it is so mobile in the soil. Did you get a recommendation for how much actual nitrogen you should use per 1000 sq ft?

Sammie,

It can be difficult to correct imbalances in individual containers filled with a soil-less potting mix. However, the heavy watering required to keep container-grown plants happy in summer ought to help leach the excess phosphorus and potassium out of the containers somewhat quickly.

To add nitrogen, you could use any of the organic sources of nitrogen like cottonseed meal, blood meal, etc.

To lower the pH you could add elemental sulfur, but be sure you don't add too much. Or, you could add a good amount (25-33% by volume) of peat moss or compost to each container. Peat moss would be more likely to affect the pH more quickly since it is acidic, but compost would also work as a buffering agent, which means it would help make available the nutrients in the soil. Sometimes, when your growing medium's nutrient balance is out-of-balance that can interfere with the plant roots ability to take up nutrients and compost can counteract that.

If I had this sort of nutrient imbalance in my containers, I'd never purchase that brand of growing medium again and, to fix the current batch, I'd likely dump out the soil from all the containers onto a large tarp, add enough compost and peat moss to make a significant change, and refill the pots. Then I'd add Espoma Tomato-Tone to each pot because it contains micronutrients and beneficial microorganisms. Or, if I couldn't find Tomato-Tone, I'd use one of the products containing beneficial mycorrhizal fungi. I'd probably add some earthworm castings to each pot as well.

Really, while the pH of 7.5 is not ideal and tomatoes would prefer it to be somewhat lower, it also is not so high that I'd be panicky or anything. I believe that high pH interferes with nutrient absorption once it hits 7.8 or so.

Hope this helps,

Dawn

Thank you all for your suggestions. I am shocked that I pay for soil that is not that good.

Do any of you know where I can purchase soil that is good? I need to deal with Lowe's, and need to make many decisions. I have about 25 bags to return. Then, I think I can take out half of the soil from the 20 containers and put it in the dogs' yard to fill in the holes. Perhaps the lower half won't matter too much that it is not good soil.

The soil that was tested was new last year, and has had a year of use by being watered almost daily. It still is this much out of proportion.

I need to find what is good, and do it fast. I intend to plant some tomatoes very early this year. I don't mind taking a chance, but I don't want to wait like last year.

If you have any ideas, I am open for them. I don't know about Lowes'

Sammy

Sammy, do have a garden or flower bed to dump some of the soil into. From what I read it is common for native soil to be low in P & K. DW has a few containers for flowers and when she wants to renew her soil, I just dump it into the garden or flower bed, so far I have had no problem doing so, but over all it is a very low ratio. Of course I don't do that if there is a disease issue.

Larry

We are going to dump the entire thing.Our dogs have a fenced in yard along the side of the house. They dig, and since they are big dogs, the dirt flies everywhere, and quickly becomes a part of the yard. We can use this soil to fill in the holes, and even raise it in parts. We can also use it as fill along the green belt where we have few plants or we can build the paths.

The money thing bothers me a lot. I thought I would be saving money last year by growing tomatoes. Actually I cannot blame the soil, because of our heat, but the soil was and has always probably been bad --- and I have spent 2.25 per bag. Each of the 20 pots took about 5 bags, and the half whiskey barrels took about 6.

Now I am going to get regular top soil and mix it with mushroom compost. I hope that will be a good combination. When I first purchase it, I will send in a sample, but by April 1 I need to be ready to plant, and still have 150 roses to take care of.

Everyone here knows what a "chore" gardening is, and you all probably agree that we love that chore, even though the pressure becomes great at times. Since I still work full time, I have to really pace myself. I plant my roses on March 15 and two weeks later the tomatoes.

Of course with the roses I only actually plant about 15, but still must prepare the beds, and be ready.

I am also going to try to find a self test so this soil business does not get too cumbersome.

Thanks for all your replies.

Sammy,

It bothers me a great deal that the P and K in that soil-less mix is so high after it has been used for a year and watered almost daily. It makes me wonder what the N-P-K was before you started using it and watering it. Are you saying you never fertilized those containers last year? I find that astonishing.

Very large companies like Lowe's that probably sell millions of bags of soil and soil-less mixes every year probably have very little control over the quality of the mixes they sell. To be able to control the content of the mixes, they'd have to make their own private label line of mixes and, in order to make it the quality mix we gardeners prefer, it would be more expensive than competing brands and wouldn't sell as well. Look at how expensive Pro-Mix is. It is a great product, but out of the price range of many Americans as far as using it to fill many large containers.

The best way to have control over the quality of the soil-less mix you use in your containers is to mix up your own. Some years I do that, and other years I purchase a soil-less mix. When I purchase a soil-less mix, I still add other stuff to it, but what I add will vary a great deal depending on what I think of the bagged mix when I open it and can see is. There's not a real formula to explain what I add and why I add it since it can vary for each bag. I just add this and that until I am convinced I've got the growing medium right before I put it in my containers.

To mix your own growing medium, Al's 5-1-1 mix from the Container forum is a good starting point. I tailor the 5-1-1 mix (5 parts pine bark fines, 1 part sphagnum peat moss, 1 to 2 parts perlite, a small amount of garden lime, and a controlled release fertilizer if desired) to meet my plants' needs in our climate. I often substitute compost or coir for some or all of the peat moss, and I like to throw in some other organic amendments as well. I can use the 5-1-1 mix in my containers for 3 or 4 years but I do add some fresh ingredients to it each year.

You might check with local, independent garden nurseries to see if any of them sell a soil-less growing medium for containers. When I lived in Fort Worth, there were nurseries and soil suppliers that sold great mixes that they made themselves or had made for them. I am sure there are places in Oklahoma that do the same thing, but you have to specify you need a container mix, not one for raised beds. Container mixes have to drain better than a mix in a free-draining raised bed.

Otherwise, your only other option is to buy what you can find in bags in stores. Miracle Grow Moisture Control mix works fine for me in containers in dry years, but not as well in very wet years, which is why I often add other ingredients to it if I am expecting a wet year. It may or may not work for you since, in an average year, your part of the state gets significantly higher rainfall that my part of the state.

I do not use regular Miracle Grow or their organic forumula either, which I found to be very poor quality when I tried it several years ago, but the Moisture Control mix has worked well for me in recent years.

There are other brands of soil-less growing mediums in stores, but the problem with any of them is that you have no idea what ingredients are in them in what proportion. Even if they list their ingredients on the back of the bag, most of them don't tell you the ratios so you don't know what you're getting. All things being equal, I'd rather buy a mix that does not have controlled release fertilizer mixed in, but those can be hard to find.

Good luck finding a solution that works for you.

Dawn

This year I have already purchase about 24 bags of the potting soil. It is called Green Country potting soil. I have spoken with some people at Lowe's, and they refunded the money for this year's soil. He said he could not complain to Green Country because they use different places each year. I also used to use Green Country top soil and Green Country mushroom compost.

My in ground garden sample for the roses came back also, but I have mixed that with previous soil, and did add Osmocote to my roses, even though I added nothing to the tomatoes.

The garden is:
nitrogen 4 and normal is 40, phosphorus 245 and should be 65, potassium 338 and should be 250.

My whole yard is larger, and there are many variables. I will work with the roses, and in the future purchase a better grade of soil.

My roses are in hardware cloth containers, so I cannot really amend the soil that well. I am not sure what to do with the older plants.

I am rather upset with Lowe's. I think that there vendors should show them some proof that their product is good. I don't think it is novel of me to have the soil tested -- it is recommended all the time.

Dawn, you are right that it is hard to find a product without the fertilizer mixed in. Lowe's just had Miracle Gro, Green Country and one other.

If someone knows of a reputable place that sells good soil, I hope you will let me know.

I am hoping that this soil won't hurt my dogs' paws.

Sammy