Plant compatibility has many aspects to consider. This post addresses the issues that I experienced associated with the proximity between peppers and tomatoes.
Taking from the ideas of “Square Foot Gardening” I attempted to maximize my limited space by alternating and nestling my pepper rows between my tomatoes. The idea was that I new the tomato plants would require a significant amount of space on both sides for maintenance and harvesting and that the peppers which would not occupy much space could coexist near and on one side of each row of tomatoes. This plan, at first had great merit and immediate benefit but as the season wore on it became clear that this was not the best idea.
I’ve learned that peppers enjoy and need significant full sun, well the tomatoes enjoy the sun too but, the tomatoes require more water than the peppers can handle and the tomato plants grow large and shade the peppers and the ground that they shared. Now the pepper plant may have continued to receive adequate sunlight but the ground and consequently the roots didn’t. The result of which causes the pepper plants to suffer.
The suffering of the peppers.
I noticed the tomatoes needs clearly, they wanted water! The leaves on the tomato plant spoke to me and I listened. I adjusted my watering plan to accommodate the the tomatoes, the ’empty can’ philosophy prevailed; the tomatoes were making a lot of noise and I responded. However the peppers were not asking for water and could not cope with constant ‘wet feet’.
Over Watering 101
Plain and simply stated, over-watering leads to disease and death. There are many pathogens that are either born or exacerbated because of excess watering. In my case the wilting of the plant, the wilting and softening of the peppers on the plant got my attention. Upon closer inspection I could see that the ground around the affected plants had been perpetually wet. The moist ground even appeared to have mildew and fungus, I had mushrooms growing!
Determination
As is my modus I photographed the plants and began my web search and discovered the symptom and the diagnosis was stem rot (Phytophthora). It is a soil-borne fungus that attacks peppers. It is Described as “particularly severe in areas where water stands around the plant.” And it recommends that “Plant(s) [be] on a raised bed for optimal drainage. The name (Phytophthora) is of Greek origin and literally translates as Phyto[n] (Plant) phthora (Destroyer)Phytophthora – Wikipedia, the free encyclopedia, also referred to as blight.
Resolution
This and related pathogens are the bane of commercial growers of crops including potatoes and are responsible Great Irish Famine (1845-1849) . That being said, the resolution for me was to remove the affected plants and discard them in the trash. DO NOT RECYCLE them in your compost. DO NOT ATTEMPT TO RECOVER THE SOIL of the root-ball for further use in your garden. The pathogens may further infect and destroy. And last but not least avoidance is the best thing to do. Ensure that you have a planting and watering plan that is amiable for the associated plants.
Wonder how long that pathogen lives in the soil around the diseased plants? If it is going to be an issue that stays in your soil in that area well into the next planting season, you may want to consider using a biological fungicide to protect your next crop there. Try PlantShield HC which contains the beneficial microbe Trichoderma harzianum. That’s a big word I can’t even pronounce, but you can find it under the name Root Shield Home and Garden, and it’s available through Territorial Seed Company, Gardener’s Supply, and Johnny’s Selected Seeds.
Also at Gardens Alive (my personal favorite) they have Plant Guardian Biofungicide which treats Bacterial spot, Powdery mildew, Rust, Gray mold, Scab, Leaf blight (which are bacterial diseases) and it suppresses Downy mildew, Fire blight, Early and late Blight, and Black rot, (fungal diseases). They say it can be applied any time of the day, in full sun and high temperatures. It will not stress the plant or burn the foliage.
I have a couple of questions. When you pulled up your diseased peppers what did the roots look like, were they white and extensive, or were they brownish and relatively small for the plant size? How much of the surrounding soil did you remove? And, a big question….since they were between your tomatoes, did the blight spread to them? I ask because I know you have the Cherokee tomato, which is an heirloom, and heirlooms are not disease resistant. I’m anxious to hear how you handle this, and your plan for prevention in future plantings, so keep us posted.
It’s a war out there. Sorry pal.
As is common, you get straight to the issue. I like that!
Since the answers to these questions are extremely technical and extensive I will summarize and provide links to the sources used for the answers. Though I referred to several sources the most of the answers come from The Fact Sheet and from the references already given (see the origional post)
Q – How long that pathogen lives in the soil around the diseased plants?
A – Not determined. As long as the environmental condition that was ideal for the fungus to grow exist, it will continue. It appears that the “makings” for this pathogen exist in the soil. If conditions are suitable it develops. According to the reference and my interpretation there are in fact two fungi that merge and enter the plant by way of the root. All information gleaned lends to the removal and destruction of affected plants and changing of the soil conditions that harbored the growth of the fungi. Additionally I found that (especially with potted plants which have an increased vulnerability) it is recommended to replace the soil. Because I found nothing that states a longevity of this pathogen and with the extensive amount of information on the subject, supported by the fact that there is no (found by me) cure for it in an affected plant it is likely that the fungi will continue to reproduce and reek havoc.
Q – Is it going to be an issue that stays in your soil in that area well into the next planting season? You may want to consider using a biological fungicide to protect your next crop there.
A – Not determined. This is not known to me. What I do know it that not all of my plants of this type and planted in this bed have fallen to this. I have seemingly healthy plants on either side of others that are dying or that I have already extracted and destroyed. In some cases weeks have past and the adjacent plants still appear well and producing. What I am certain of is that the plants that have fallen were defiantly soaked footed and in some cases had visible mildew and even mushrooms at the base, the other plants did not. My references state that the pathogen can be present for extended periods and not show signs until sufficient stress occurs and warns to keep an eye on other plants. It is also note worthy that there are different ‘versions’ of this and that each has its own host range, so it is possible for the fungi to occur around a particular plant but not be a danger to its plant type.
The use of fungicide is worth considering as a preventative but will not cure an infected plant.
Q – When you pulled up your diseased peppers what did the roots look like, were they white and extensive, or were they brownish and relatively small for the plant size?
A- Not determined. I discarded them without consideration of the appearance of the roots, but not to worry, I have two other pepper plants that I will be extracting today or tomorrow and will document the root condition and update this post.
Q – How much of the surrounding soil did you remove?
A – I remove the root ball. A significant amount of soil fell from the ball, much of the root system was visible. I did not attempt to effectively excise it in its entirety. My expectations were/are that the change of the soil condition (reducing the water) along with the refreshing of the soil (preparing it for the next cycle with fertilizer and amendments) and a change of the plant type would suffice. I maybe wrong. Also it is important to note that I “plug planted”, simply improving the whole that the seedling was planted in.
Q – Since they [the affected peppers] were between your tomatoes, did the blight spread to them?
A – Fortunately not. At this time and it has been more than 4 weeks since I first noticed and began to deal with this, that it has not appeared and in any other plant type. which may be supported by the various strains having specific host types, perhaps. My Cherokees were/are fine!
It is war out there! Truth be told, though the enemies are many and are clever in their ways we shall prevail! Thanks for the great questions. I will keep you posted.
Reference: The Fact Sheet See original post for other references.
Well, I finally got around to completing this response to the questions asked concering the condition of the plant, specificly the roots.
I pulled the plant and it came up very easily, very little resistance. The roots did not appear to have established very much at all. This plant as is true with all of my peppers were purchased as seedlings. Ruffly speaking I have lost half of my peppers and all showed the same symptoms of wilting and excessive moisture at the root. All of the pepper plants yeilded, a few not as well as some others, but all did. So as per your question: A- The roots were brown and relatively small.
Sad. I wondered if you had any root knot nematode problem. I do, and I am very familiar with the roots dealing with nematodes. They are brown, tough, small for the plant and full of galls, or knots that inhibit the plant from taking up the nutrients it needs from the soil. I grow lots of french marigolds to deal with the nematodes which “they say” are prevalent in our desert soils. I guess it’s just my soil, as I have yet to meet anyone who gardens out here that has this issue.
Perhaps the raised rows you are doing now will solve this problem for you. I hope so. I love to hear the solutions. Makes me feel a little more prepared for whatever comes up in my garden next.
We all have our battles but I rather enjoy hearing success stories. They give me hope.