Can you get away with only changing parf of the soil ?

[Elliot]

we use the largest green pots bought at home depot. To change the entire soild would involve over 2 cu feet of miracle grow potting mix plus composted manure. A friend in the same situation asked if he could change only part of the soil. Would this work?

[Rockporter]

sure, why not?

I would just fluff the mix mix perlite and dolomite lime, then use the ferts you want. I don't know if you are using self watering containers or not but I use the mix over and over again. As long as you didn't have any diseases that would warrant tossing the mix then you should be good.

[lakelady]

I'm glad I saw this post, I was wondering the same thing. I have several SWC from last year and sure did use a lot of mix. I think I'll dump 1/2 and refresh it up.

[baileyj]

Elliot,
I agree with Rockporter. I am not sure which containers you are using. I grow 90% in Earthboxes and am using mix that is now 8 years old. Each year I refresh the mix as Rockporter said and I replace the top few inches where the fertilizer strip was located and any areas with salt residue...I do this in all my self watering containers.

For regular planters I follow much the same process--discarding any fertilizer if I had a strip, dumping the mix into a wheelbarrow and adding perlite or more mix to lighten up the mix.
If I find boggy, wet conditions in the container I may replace 50-75% of the mix, but not all. This I have found only after many years in the same Earthbox and not in any other containers.

I did have a scare a few years ago and thought I had late Tomato blight so I discarded about 15 boxes of mix. In retrospect I do not think that was my problem but I was hesitant not to take action.

As long as the soil looks, smells and feels healthy I would reuse...after refreshing it !
Good luck !
Judi

[Elliot]

We did have fungal problems or heat problems last summer with all of our tomato plants. Wouldn't the cold weather kill any of the fungi in the soil?

[bcday]

The two or three most common fungal diseases -- Early Blight (Alternaria solani), Late Blight (Phytophthora infestans) and Septoria -- live only on the aboveground parts of the plants, not in the soil or on the roots.

Early Blight and Septoria can overwinter on dead infected tops, but all you need to do is make sure every bit of diseased leaves, stems and fruit are removed from your garden by the end of the season. That will eliminate them as a source of spores that might infect next year's plants. Once they are gone, so is the fungus. If you get rid of the diseased tops and your plants still get infected again next year, it is from spores that came in on the wind from somewhere else or from infected plants that you bought from a nursery, not from your soil.

If the fungal disease affecting your plants is Fusarium or Verticillium, those are soil-borne and it would be worth looking specifically into how to distinguish those particular diseases from other problems so that you don't waste time and money replacing your container mix unnecessarily.

[SharonRossy]

I have done both, completely removing and replacing and then getting lazy and partially removing what I had. I had similar results either way. The only time I felt the need to completely remove and sterilize was when I used a container mix that was not soilless. But this year I am going to be using the smart pots and will use the 511 mix of pine bark fines, peat and perlite with lime and fertilizer.

[ginger2778]

Originally Posted by bcday

The two or three most common fungal diseases -- Early Blight (Alternaria solani), Late Blight (Phytophthora infestans) and Septoria -- live only on the aboveground parts of the plants, not in the soil or on the roots.

Early Blight and Septoria can overwinter on dead infected tops, but all you need to do is make sure every bit of diseased leaves, stems and fruit are removed from your garden by the end of the season. That will eliminate them as a source of spores that might infect next year's plants. Once they are gone, so is the fungus. If you get rid of the diseased tops and your plants still get infected again next year, it is from spores that came in on the wind from somewhere else or from infected plants that you bought from a nursery, not from your soil.

If the fungal disease affecting your plants is Fusarium or Verticillium, those are soil-borne and it would be worth looking specifically into how to distinguish those particular diseases from other problems so that you don't waste time and money replacing your container mix unnecessarily.

Great news because this is the first year I have been fighting Septoria all season.i have27 earthboxes. I love them.
Marsha

[Elliot]

BCDay: Thanks for you input. We grow our tomatoes in large HD pots. We remove the upper most amount of the plants each Fall but the base and roots are too hard to remove so we remove them right now.

I was at a local nursery today. They suggested that I soak my plant roots with an antifungal and then use it periodically as a foliar spray. What is your take on it?

[bcday]

What antifungal did the nursery suggest? Most of the anti-fungal foliar sprays that are safe for home gardeners to use on vegetables act by coating the foliage with a physical barrier that prevents the fungal spores from accessing the leaf. They were not designed for use as a soil drench and wouldn't kill any fungus in the soil. If your plants have one of the three foliar fungal diseases I mentioned above (Early Blight, Late Blight, or Septoria), soaking the roots with a foliar anti-fungal spray won't help. Those three diseases don't grow on or in the roots at all and don't live in the soil by themselves either.

The antifungal solutions that are used on commercial farm soils for the soil-borne Fusarium or Verticillium require special equipment, are not safe for home gardeners to use, and are generally not available to people who aren't licensed to use them. There are folks here on the forum who can advise you as to how they deal with Fusarium and Verticillium if your plants become infected with one of those.

If you want to buy something to soak the roots with, read the label instructions thoroughly first to see if the product is intended for that use.

[amideutch]

I would definitely do a root dip consisting of MycoGrow Soluable, Actinovate and Biota Max. This will help in disease prevention and plant growth. Ami

[bcday]

What diseases does a root dip prevent?

[baileyj]

Amazing to learn something every day....I used the dip Ami speaks of which I found here on TV last year. But....I have never tested my water for chlorine, which I am sure has been added...I find out now it defeats the purpose of all these beneficials I have started to add.....
I am now planning to add another chlorine filter to my Automated watering system in addition to the sediment filter...
Here I thought I was ahead doing good things for my plants and I was just killing off all the good additions....
Judi

[amideutch]

What diseases does a root dip prevent?

You can check the respective sites as to the diseases they control. All three will help in controlling most soil borne diseases. Also they will enhance plant growth and the myco's will set up a symbiotic relationship with the plant that will enhance nutrient uptake by the plant and will also assist in fighting disease.

As far as the chlorine is concerned most of it will dissipate in the first inch of top-soil so the loss of myco's/bacteria should be minimal. But a chlorine filter wont hurt either.

Ami

[bcday]

Originally Posted by amideutch

I would definitely do a root dip consisting of MycoGrow Soluable, Actinovate and Biota Max. This will help in disease prevention and plant growth. Ami

Ami, you said "help in disease prevention". I did do a search to find out what diseases a root dip would prevent and didn't find any. Also I prefer to see independent studies, not claims made by the manufacturers. A URL that has .edu rather than .com might be a more credible source.