AboutSojourner Expertise Intensive gardening along the lines of square-foot gardening and no-till methods such as Ruth Stout and "lasagna" gardening. Fed a family of 7 from the produce grown in the backyard of a city lot. Knowledgeable about most common garden crops, excluding cole crops other than cabbage (e.g. broccoli, brussel sprouts, cauliflower etc. are not my cup of tea). Can help you to make the most of the space that you have - for instance, many community garden plots are fairly small. There are ways to maximize the space you have. Smaller is often better because it's not only more efficient spacewise, it's also easier to take care of - and the easier it is to take care of, the more likely you are to have a successful garden. No yard space whatsoever? I can help you with container growing as well. Give me a shout and I'll try to help.
Experience Vegetable gardener for most of my life, homesteaded for 8 years. Currently have my tiny yard (1'x15' strip along the back fence and a 3'x20 strip along the south side of the house) planted with 2 eggplants, 2 tomatoes, lettuce, coriander, green onions, basil, 4 bell pepper, 4 green pepper, watermelon, 3 yellow squash, 3 zucchini, and green beans. And flowers galore.
Education/Credentials College educated, currently working out a mid-life crisis by getting my doctorate and changing my profession
Question I started a container vegetable garden a little over a month ago. The plants are outside, on my deck, in a 24-gallon tub. I filled the tub with a combination of potting soil from Home Depot and soil with dead leaves from my yard, and some kitchen veggie scraps (thinking it would become compost and was enough soil to grow plants already). Of the things I planted, only the squash and cucumbers were growing really well.
Then I noticed a LOT of bugs crawling on the plants. It looks like there are fireants, along with tiny brown winged insects, and some white insects, and others.
So I went to Pike Nursery and asked for advice on something organic to control the bugs. They sold me an insecticidal soap spray (only 1% solution, and very expensive!), which I sprayed on last week.
The next day, I started seeing brown spots all over the leaves of the squash and cucumber plants. I thought that the spots were a result of the insects having transmitted some kind of fungus or other plant disease, rather than the result of using such a weak solution of insecticidal soap spray.
After a heavy rain, thinking that the rain would have washed the spray off, I sprayed the plants again, yesterday.
Today, the leaves are nearly brown all over, and shriveling at the edges!
I have no idea whether this is because of the spray, or because of the bugs, or something in the soil, etc.
How can I get a leaf tested to find out what the brown really is? (I.e., fungus, bacteria, or "burn" from the spray - which seems unlikely to me.)
Answer Are you sure they're fire ants? Fire ants are extremely aggressive and they build large mounds - typically foraging fire ants won't go more than 40 or 50 feet from their home mound. If you really think you have fire ants (you don't mention what part of the country you live in) it's important for your own safety to locate the mound. If you run over the mound with a lawnmower you could be badly stung, or stepping into it by accident, etc. However they're probably not much of a threat to your squash. Amdro is a widely available product that is effective in killing fire ants - definitely NOT organic though. It's not dangerous to humans or pets if properly handled but it's not organic. Just be sure they're really fire ants before you even think of doing anything to them.
In my experience insecticidal soaps do nothing at all to protect plants from insect damage or disease. I doubt it was directly related to the damage you are seeing - unless you sprayed heavily enough to leave drops on the surface of the plant and it was a VERY sunny, very hot day. It is possible for the drops of liquid to act as a magnifying glass and literally burn small areas of the plant surface before they evaporate.
Without a picture to go from it's difficult for me to tell what disease or insect might be responsible for the damage. However, introducing kitchen scraps and un- or partially rotted leaves into the soil mix also introduced the possibility of contamination from a variety of soil-born funguses and molds that we might not normally see in garden vegetables, especially in such a small container.
I'm guessing, but a typical 24 gallon tub would be a bit over 2' in diameter and about 12" deep. That's really not big enough to plant many plants in. I wouldn't think you could get more than 2 or at most 3 bush type squash plants in that size container and expect to get any fruit. Crowding may be an issue here, as squash and cucumbers are more highly susceptible to diseases in crowded conditions.
I think your problem is complicated by the soil mixture being used. You don't say what kind of bagged soil you got from Home Depot. All "potting soils" are not the same. I tend to use Miracle Gro potting soil and Garden Soil. In the type of container you are describing I would use a 50/50 mix of the Potting soil and the Garden soil. Mixing whole scraps or partially rotted material into your soil is risky at best, and it can be very problematic in such a small closed system as a 24 gallon tub.
If possible I would dump the container, rinse it thoroughly with diluted bleach to sterilize it, and start over with fresh mix. You could substitute peat moss for the Miracle Gro Potting Soil mix - that mix is nearly all peat moss anyway, which is why I wouldn't typically use it straight in the type of container you describe. It sounds like your plants are goners anyway, and at least squash is a fast grower.
Another potential problem is drainage. Does this container have drainage holes in the bottom? If not, your plants could be getting wet feet. Water in the bottom of the container would not be visible from the top, and would contribute to the formation of anaerobic systems which breed a variety of toxins, fungi, molds and diseases that would only be helped along by the half-rotted leaf mixture and scraps you added to the soil. Composting IN the container where you are trying to grow veggies doesn't work very well unfortunately as the process of breaking down organic matter robs the soil of oxygen. Your plant roots NEED oxygen to grow well.
If there is no way for the container to drain excess water from the bottom you will need to create one. The easiest way to do this is to dump the container (another reason to dump it and start over). If it's not too heavy or if you have a couple of beefy strong types to help you, you could also get around this by having the beefy strong types tilt it up enough for you to get at the bottom with a large screw and a screw driver. DON'T try to use an electric powered screwdriver or drill; if there's water in the bottom of the container, it'll start dripping out as you drill the hole and short out your tool at best, electrocute you at worst.
A hand drill would be an excellent way to do this, but they're darn hard to come by these days. I've drilled drainage holes in the bottom of plastic containers using a handheld screwdriver, but if the plastic of your container is very thick you may need a third beefy type to do that for you as well. Again, dumping it would make this child's play since you could just turn the tub upside down and pop a half-dozen or so evenly spaced holes into the bottom for drainage before refilling. If you're worried about dirt falling out, cover the holes with folded coffee filters before adding the dirt back in. That will keep the dirt in but still allow the water to drip through and out.
I recommend a mixture of Rotenone and Pyrethrins or Pyrethrum. Bonide makes this, here is a link to one source and there are many others if you google:
Rotenone is an organic pesticide of long-standing, though some organic experts no longer consider it truly organic because if a lot of it gets into a water supply due to mishandling or overspraying it can kill the fishes there. However the amount used to spritz a handful of plants is unlikely to poison anything even if you mishandle it. This mixture can be hard to find in local stores so I've bought mine online for years. I've used it for over 30 years and it's been both safe and effective for me. If you have an ornamental koi pond right next to the tub, you might not want to use it; otherwise, it's fine. That should take care of any pest problem you might have (and keep in mind that all bugs climbing around on a plant are not pests; some of them are there to EAT the real pests).
In order to try to identify the disease, try this link:
There are a variety of University Extension fact sheets about cucurbit/squash diseases and pests listed there. Most include pictures, to aid you in identifying the problem on YOUR plant.
Or post to me again with more details, maybe a link to pictures on photobucket or some other picture sharing site. I'll try to identify the problem if I can, but I can't do it from the information I have so far.
I hope something in this will be helpful to you. Feel free to ask again or send me more information or links to photos and I'll be happy to respond again.
